1 00:00:02,280 --> 00:00:05,840 Cannabis... It's merely a plant, a wild weed... 2 00:00:05,840 --> 00:00:07,840 but it produces a range of effects that is unmatched. 3 00:00:08,160 --> 00:00:10,720 but it produces a range of effects that is unmatched. 4 00:00:10,720 --> 00:00:13,320 For some, it's a blissful release... 5 00:00:13,320 --> 00:00:15,160 It is nice. 6 00:00:15,160 --> 00:00:19,240 It is so nice. It is nicer than nice. 7 00:00:19,240 --> 00:00:23,520 It is... I don't know if I can say this on camera, but it's almost as nice as sex. 8 00:00:23,520 --> 00:00:29,760 While for others, it's something that seems to have unravelled their minds and emptied their lives. 9 00:00:29,760 --> 00:00:32,040 I'm an addict and 10 00:00:33,960 --> 00:00:37,200 I loathe myself, I really do. 11 00:00:37,200 --> 00:00:39,520 I'm ruled by it, I'm ruled. 12 00:00:39,520 --> 00:00:42,160 And I don't think it'll ever stop until I'm dead. 13 00:00:45,120 --> 00:00:47,880 I hear the voice of a girl I used to know. 14 00:00:47,880 --> 00:00:53,680 Sometimes she's told me to commit suicide and things, but I tend to just ignore it. 15 00:00:53,680 --> 00:00:56,280 In this film, I want to get to the 16 00:00:56,280 --> 00:01:01,240 bottom of this conflict by asking the most basic questions about cannabis. 17 00:01:01,240 --> 00:01:04,080 Can it really cause schizophrenia? 18 00:01:04,080 --> 00:01:08,280 The vulnerable group are children under 15 19 00:01:08,280 --> 00:01:12,440 receiving high doses or concentrations of THC repeatedly. 20 00:01:12,440 --> 00:01:15,880 Can it lead you to take harder drugs? 21 00:01:15,880 --> 00:01:18,120 You don't have enduring 22 00:01:18,120 --> 00:01:22,400 biological changes that occur because of the cannabis exposure. 23 00:01:22,400 --> 00:01:26,280 Or, could cannabis even be good for you? 24 00:01:26,280 --> 00:01:31,160 With all the publicity around the link with cannabis smoking and the potential of increasing 25 00:01:31,160 --> 00:01:36,440 the risk of psychosis, here we have a component of the plant which itself is anti-psychotic. 26 00:01:36,440 --> 00:01:40,280 The science is so often obscured by opinion 27 00:01:40,280 --> 00:01:44,720 but what does the latest research reveal about the world's favourite drug? 28 00:01:56,160 --> 00:01:59,160 In my job as a psychologist, I deal with addiction. 29 00:01:59,160 --> 00:02:03,000 I work with people with heroin and crack cocaine dependence. 30 00:02:03,000 --> 00:02:05,240 But with heroin and crack cocaine.. 31 00:02:05,240 --> 00:02:10,760 I regularly see people brought to their knees, lives ruined, even deaths. 32 00:02:10,760 --> 00:02:16,640 But by comparison, for cannabis, it seems to me the effects are like a walk in the park. 33 00:02:16,640 --> 00:02:23,080 And yet this is the one drug that's rarely out of the public eye, and shrouded in controversy. 34 00:02:23,080 --> 00:02:28,000 And that's because more people use cannabis than all other illicit drugs put together. 35 00:02:28,000 --> 00:02:31,880 According to a United Nations report, 36 00:02:31,880 --> 00:02:36,760 almost one in 20 adults across the globe uses it each year. 37 00:02:36,760 --> 00:02:39,280 Of the people watching this programme, 38 00:02:39,280 --> 00:02:43,040 one in three will have tried it, and thousands will be smoking it now. 39 00:02:44,800 --> 00:02:49,480 I've tried cannabis. I've smoked it a few times. And yes, I've inhaled. 40 00:02:49,480 --> 00:02:52,400 Did I like it? Not really. 41 00:02:52,400 --> 00:02:59,080 I was giggly, and having said that, though, I felt a bit uneasy and 42 00:02:59,080 --> 00:03:02,520 a bit behind the conversation, a bit thick, to be honest. 43 00:03:02,520 --> 00:03:04,960 And it wasn't really for me. 44 00:03:04,960 --> 00:03:11,480 But I can see the attraction, I can see that feeling out of control, 45 00:03:11,480 --> 00:03:14,400 relaxed and enjoying the flow of a conversation 46 00:03:14,400 --> 00:03:17,000 would be, for many people, a good thing to do. 47 00:03:17,000 --> 00:03:23,000 But I want to know why one simple weed has such a profound impact on all our lives. 48 00:03:25,720 --> 00:03:31,160 The story of the cannabis plant begins 50 million years ago, in an unexpected place. 49 00:03:37,080 --> 00:03:39,320 This is Kazakhstan. I'm hoping to find out 50 00:03:39,320 --> 00:03:44,040 why this psychoactive plant might have evolved here, of all places. 51 00:03:47,280 --> 00:03:53,520 Professor Kanat Sarsenbaev is Kazakhstan's national cannabis expert. 52 00:03:53,520 --> 00:03:56,760 He takes me to the nearby mountains to explain. 53 00:04:02,680 --> 00:04:05,520 So here we are in the Tian Shan mountains. 54 00:04:05,520 --> 00:04:08,520 Is this the origin of cannabis? 55 00:04:08,520 --> 00:04:10,800 I think so, 56 00:04:10,800 --> 00:04:18,080 because cannabis evolved in this place many million years ago, 57 00:04:19,360 --> 00:04:26,840 After evolving, it distributed through the Tian Shan chain to China. 58 00:04:26,840 --> 00:04:29,920 After this, to all the world. 59 00:04:29,920 --> 00:04:37,720 The Tian Shan mountain chain stretches 2,500km, reaching into China and Pakistan. 60 00:04:37,720 --> 00:04:39,800 While it's hard to know exactly where 61 00:04:39,800 --> 00:04:45,160 along this chain cannabis evolved, what it evolved from is clear. 62 00:04:45,160 --> 00:04:50,600 Cannabis is a close relative of the hop plant, but with one crucial difference. 63 00:04:50,600 --> 00:04:55,520 Cannabis contains a chemical called THC, tetra-hydro-cannabinol, 64 00:04:55,520 --> 00:04:58,680 the active ingredient, which gets you stoned. 65 00:04:58,680 --> 00:05:00,400 Here we are. 66 00:05:00,400 --> 00:05:06,680 We're in the mountains here and it's not in great abundance but here it is, here's a specimen of cannabis. 67 00:05:06,680 --> 00:05:11,200 This plant has been here for millions of years but what I don't understand is why 68 00:05:11,200 --> 00:05:18,360 would this plant have evolved THC, this psychoactive compound. What was the reason for the cannabis plant? 69 00:05:18,360 --> 00:05:26,360 I consider that accumulation of THC gives a lot of privilege to cannabis. 70 00:05:26,360 --> 00:05:33,680 This plant very resistant to ultra-violet. Extremely. 71 00:05:33,680 --> 00:05:39,160 So it's a defence against ultra-violet light at this altitude? 72 00:05:39,160 --> 00:05:42,920 Another thing, the taste of the leaves.. you can taste if you want. 73 00:05:42,920 --> 00:05:46,640 I'll have a little bite here. Yes, it's not so good. 74 00:05:49,280 --> 00:05:51,200 Oh, yeah, that's really bad. 75 00:05:51,200 --> 00:05:57,000 Yes, cattle consider the same and they don't eat leaves and 76 00:05:57,000 --> 00:05:59,280 plant during the vegetation period. 77 00:05:59,280 --> 00:06:05,360 So just like any other plant, cannabis evolved defences to enable it to survive. 78 00:06:05,360 --> 00:06:11,640 It just so happens that in the case of cannabis, these defences took the form of the chemical, THC. 79 00:06:14,640 --> 00:06:18,960 But the reason why THC gets you stoned is due to another, 80 00:06:18,960 --> 00:06:22,400 entirely unrelated accident of evolution. 81 00:06:29,760 --> 00:06:34,600 The origins of our response to cannabis strangely preceded the existence of the plant... 82 00:06:36,240 --> 00:06:42,160 ..and can be traced back millions of years to primitive creatures living in the ancient oceans. 83 00:06:42,160 --> 00:06:47,000 And those creatures still exist today, in the more familiar waters of Portsmouth. 84 00:06:47,000 --> 00:06:51,800 What we're looking for are some buoys, or a boat that has been here a while, 85 00:06:51,800 --> 00:06:58,520 and maybe on the underside we'll see hanging off the bottom of the buoy hundreds of these creatures. 86 00:07:03,880 --> 00:07:06,560 In a minute we can take a look with a camera, 87 00:07:06,560 --> 00:07:10,640 so if I just set that up now as we're coming here. 88 00:07:13,600 --> 00:07:16,320 Shall I grab this monitor? Yeah, grab the monitor. 89 00:07:16,320 --> 00:07:19,560 You should hopefully, as I go under the water 90 00:07:19,560 --> 00:07:22,800 now start to see one or two of the sea squirts. 91 00:07:22,800 --> 00:07:25,760 Oh, yes! Let's go further down, and you can see one 92 00:07:25,760 --> 00:07:28,240 there right now in the light. Can you see it? 93 00:07:28,240 --> 00:07:30,320 Oh, yes, now I can see. Close-up. 94 00:07:30,320 --> 00:07:34,080 And there's more here. There we are. 95 00:07:34,080 --> 00:07:36,760 But what on Earth 96 00:07:36,760 --> 00:07:42,240 does a sea-squirt have to do with the way cannabis affects the human brain? 97 00:07:42,240 --> 00:07:47,280 Well, if we go back say 500 million years ago to the oceans 98 00:07:47,280 --> 00:07:50,440 that would have been full of creatures like these 99 00:07:50,440 --> 00:07:54,600 before there were fish and animals with backbones in the sea. 100 00:07:54,600 --> 00:07:59,440 We would find living in the oceans, thriving, creatures such as these 101 00:07:59,440 --> 00:08:03,240 sea-squirts, that we find here on the marina today. 102 00:08:03,240 --> 00:08:09,560 And they have within them, very simple nervous systems 103 00:08:09,560 --> 00:08:13,880 that operate in much the same way that our nervous systems operate. 104 00:08:18,400 --> 00:08:22,480 In all animals, the nervous system is made of the same components - 105 00:08:22,480 --> 00:08:25,880 large numbers of nerve cells carrying electrical signals, 106 00:08:25,880 --> 00:08:27,960 and wherever these cells meet, 107 00:08:27,960 --> 00:08:31,040 the signal is passed from one cell to a receptor in the next cell, 108 00:08:31,040 --> 00:08:34,120 by a chemical messenger called a neurotransmitter. 109 00:08:34,120 --> 00:08:38,800 Across the brain there are different types of these neurotransmitters 110 00:08:38,800 --> 00:08:40,960 such as dopamine and serotonin. 111 00:08:40,960 --> 00:08:46,440 All animals from donkeys to humans have inherited this basic structure. 112 00:08:46,440 --> 00:08:48,240 But way back in time, 113 00:08:48,240 --> 00:08:52,840 the sea squirt evolved an innovation to this system. 114 00:08:52,840 --> 00:08:56,800 What happened was the nervous system acquired a new chemical, 115 00:08:56,800 --> 00:08:59,680 a chemical if you like that had a new flavour, 116 00:08:59,680 --> 00:09:04,680 a new type of chemical, and it's this chemical that is related 117 00:09:04,680 --> 00:09:07,480 in structure and a similar shape 118 00:09:07,480 --> 00:09:09,760 to the chemical that's found in cannabis. 119 00:09:11,680 --> 00:09:13,880 Because of this similarity, 120 00:09:13,880 --> 00:09:17,880 these new signals came to be known as cannabinoids. 121 00:09:17,880 --> 00:09:20,760 On this buoy here, 122 00:09:20,760 --> 00:09:24,960 you can see quite a lot of them. And, what's been found is 123 00:09:24,960 --> 00:09:29,720 that these compounds, the cannabinoid type compounds, 124 00:09:29,720 --> 00:09:33,560 they affect the time it takes for the siphon to close 125 00:09:33,560 --> 00:09:35,280 in response to touch. 126 00:09:35,280 --> 00:09:39,520 It in fact takes longer for the siphon to close 127 00:09:39,520 --> 00:09:43,080 when they've been exposed to these cannabinoid compounds. 128 00:09:46,160 --> 00:09:49,600 Once the cannabinoid receptor evolved in the sea-squirt 129 00:09:49,600 --> 00:09:53,840 then it was inherited by every other vertebrate animal which followed 130 00:09:53,840 --> 00:09:56,160 including us humans. 131 00:10:00,240 --> 00:10:03,160 It was only a matter of time before one of these creatures 132 00:10:03,160 --> 00:10:05,880 would encounter the cannabis plant, 133 00:10:05,880 --> 00:10:09,800 so that THC and the cannabinoid receptor would meet. 134 00:10:09,800 --> 00:10:14,680 Since it was here in East Asia that cannabis first proliferated, 135 00:10:14,680 --> 00:10:18,640 it was probably here that that first meeting took place. 136 00:10:18,640 --> 00:10:22,520 It's not really difficult to imagine how it happened, 137 00:10:22,520 --> 00:10:24,960 I mean no-one knows for sure 138 00:10:24,960 --> 00:10:28,600 when THC and the cannabinoid receptor first came together 139 00:10:28,600 --> 00:10:31,640 but it has to have been here in these mountains. 140 00:10:31,640 --> 00:10:35,400 And whether it was an animal who, hungry, 141 00:10:35,400 --> 00:10:39,520 overcame the unpleasant taste and had a good munch on a cannabis bush, 142 00:10:39,520 --> 00:10:42,840 or it was a bird flying around, or a rodent... 143 00:10:42,840 --> 00:10:46,880 the first stoned animal is lost to history. 144 00:10:46,880 --> 00:10:48,920 In that very first stoned animal, 145 00:10:48,920 --> 00:10:53,360 THC from the cannabis plant flowed from its gut into its bloodstream 146 00:10:53,360 --> 00:10:56,040 and was carried to its brain. 147 00:10:56,040 --> 00:10:59,240 There, it met the cannabinoid receptor evolved so many 148 00:10:59,240 --> 00:11:01,960 millions of years earlier in the humble sea-squirt. 149 00:11:01,960 --> 00:11:04,920 And it just so happened to fit... 150 00:11:04,920 --> 00:11:06,880 like a key in a lock. 151 00:11:11,960 --> 00:11:14,920 It was inevitable that eventually 152 00:11:14,920 --> 00:11:19,080 cannabis would meet its perfect partner...us. 153 00:11:21,560 --> 00:11:25,480 It's not known exactly when humans started consuming cannabis, 154 00:11:25,480 --> 00:11:28,920 but there's evidence that it's been used in this region 155 00:11:28,920 --> 00:11:30,960 for nearly three thousand years. 156 00:11:32,600 --> 00:11:37,080 Nomadic tribes passing through Kazakhstan would pick the plant 157 00:11:37,080 --> 00:11:41,240 and then distribute it selling it along the silk road and other ancient 158 00:11:41,240 --> 00:11:43,880 supply routes, to China, to India 159 00:11:43,880 --> 00:11:49,240 and to other countries to the west, And in a way cannabis joined 160 00:11:49,240 --> 00:11:51,880 the ancient commodities of salt and tea, 161 00:11:51,880 --> 00:11:55,720 and its progress from that point on became unstoppable. 162 00:12:00,840 --> 00:12:07,280 From 2700BC cannabis was used in China, as a treatment for pain, 163 00:12:07,280 --> 00:12:10,240 malaria and constipation. 164 00:12:12,200 --> 00:12:16,880 From there, as it spread along trade and slave routes, cannabis became 165 00:12:16,880 --> 00:12:21,040 more closely entwined with human history than any other illicit drug. 166 00:12:32,520 --> 00:12:36,000 Despite the global and enduring popularity of cannabis, 167 00:12:36,000 --> 00:12:39,800 modern science is only just beginning to comprehend its effects. 168 00:12:42,160 --> 00:12:44,320 Here, just outside Washington DC, 169 00:12:44,320 --> 00:12:47,360 scientists are trying, for the first time, 170 00:12:47,360 --> 00:12:51,800 to find the density and location of the cannabinoid receptors 171 00:12:51,800 --> 00:12:53,840 in the human brain. 172 00:12:53,840 --> 00:12:57,280 Conducting the research is Dr Garth Terry. 173 00:13:01,240 --> 00:13:04,720 What stage are you at, what's happening? We have our volunteer here 174 00:13:04,720 --> 00:13:08,400 who is being put into the scanner. First we have to make sure 175 00:13:08,400 --> 00:13:12,640 his head's in the right position, so he has this white mask on his face. 176 00:13:16,560 --> 00:13:18,280 What are you injecting him with? 177 00:13:18,280 --> 00:13:21,280 We're injecting him with the radioactive drug, 178 00:13:21,280 --> 00:13:22,640 it works like a dye. 179 00:13:22,640 --> 00:13:26,120 It targets only the cannabinoid receptors throughout the entire body 180 00:13:26,120 --> 00:13:28,800 and we're imaging the cannabis receptors in the brain. 181 00:13:28,800 --> 00:13:31,240 So this drug will accumulate in the brain 182 00:13:31,240 --> 00:13:34,640 and we'll get a picture of where those cannabinoid receptors are 183 00:13:34,640 --> 00:13:37,320 and how dense they are throughout the entire brain. 184 00:13:37,320 --> 00:13:41,280 By mapping out where cannabinoid receptors exist in the brain, 185 00:13:41,280 --> 00:13:43,200 and in what density, 186 00:13:43,200 --> 00:13:47,280 it should help shed light on the role of the cannabinoid system 187 00:13:47,280 --> 00:13:50,080 which scientists are only just beginning to understand. 188 00:13:52,760 --> 00:13:57,640 What would you say the function is of these endo-cannabinoid chemicals? 189 00:13:57,640 --> 00:14:01,040 They act like a dimmer switch for other neurotransmitters, 190 00:14:01,040 --> 00:14:04,120 like dopamine, when they're released in large quantities. 191 00:14:04,120 --> 00:14:07,200 You need to have a way to turn down that signal, 192 00:14:07,200 --> 00:14:09,920 sort of turn down the amount of neurotransmitter released. 193 00:14:09,920 --> 00:14:14,040 Why do these other chemical messengers need regulating? 194 00:14:14,040 --> 00:14:17,720 That's a good question. If you have too much of a signal, 195 00:14:17,720 --> 00:14:20,760 it can actually be toxic to some brain cells. 196 00:14:20,760 --> 00:14:23,360 Imagine the case in epilepsy. 197 00:14:23,360 --> 00:14:26,480 A lot of message is getting across, it's not being regulated 198 00:14:26,480 --> 00:14:29,640 it's all garbled, it's being sent all at once, in full force. 199 00:14:31,200 --> 00:14:36,000 In cases such as epilepsy, too much of a neurotransmitter is released, 200 00:14:36,000 --> 00:14:40,680 flooding through the brain and activating too many nerve cells. 201 00:14:40,680 --> 00:14:43,760 But when the cannabinoid receptors are activated, 202 00:14:43,760 --> 00:14:45,160 they cause the nerve cells 203 00:14:45,160 --> 00:14:48,000 to reduce the amount of neurotransmitter they release. 204 00:14:48,000 --> 00:14:51,680 In this way, the cannabinoid system keeps the brain stable, 205 00:14:51,680 --> 00:14:54,680 with levels of neurotransmitters at a happy medium. 206 00:14:57,040 --> 00:15:00,040 After five hours, the scan is complete. 207 00:15:00,040 --> 00:15:02,680 So Garth, have you got the results in? 208 00:15:02,680 --> 00:15:07,720 Yes, we finished our five-hour scan and let me show you what we have. 209 00:15:07,720 --> 00:15:10,760 So this is an image from our subject from today. 210 00:15:10,760 --> 00:15:12,920 The receptors are highlighted in what colour? 211 00:15:12,920 --> 00:15:17,040 In bright red. Well, any colour you see, there are receptors, 212 00:15:17,040 --> 00:15:20,920 and red is the really dense areas, and you can see there's a lot of red and yellow. 213 00:15:20,920 --> 00:15:24,960 Green and blue are the really not dense areas, where there are not many receptors. 214 00:15:24,960 --> 00:15:27,680 So they really are everywhere? Yes. 215 00:15:27,680 --> 00:15:32,280 They are the densest receptors in the brain, 216 00:15:32,280 --> 00:15:36,160 the most populated throughout the entire brain. 217 00:15:36,160 --> 00:15:39,400 Are they only in the brain or are they in other parts of the body? 218 00:15:39,400 --> 00:15:43,200 I can show you an image of a whole body scan we've done here, here's one. 219 00:15:43,200 --> 00:15:45,080 Oh, my god, look at that. 220 00:15:45,080 --> 00:15:48,800 You can see it goes right into the brain, look how hot that is. 221 00:15:48,800 --> 00:15:51,800 But there's also cannabinoid receptors in the liver. 222 00:15:51,800 --> 00:15:55,840 Look at the bone marrow, the vertebral column, the ribs. 223 00:15:55,840 --> 00:16:01,480 So how does what we're seeing in this image relate to the experience of using cannabis? 224 00:16:01,480 --> 00:16:06,200 Well, look at the amount of cannabinoid receptors in the brain - a lot of them. 225 00:16:06,200 --> 00:16:09,480 A lot of the effects of cannabis use are in the brain. 226 00:16:09,480 --> 00:16:16,360 Euphoria... As an anxiolytic, it dissolves your anxiety or it can even cause your anxiety. 227 00:16:16,360 --> 00:16:18,880 So cannabis abusers or cannabis users 228 00:16:18,880 --> 00:16:21,240 talk about having this high, this euphoria, 229 00:16:21,240 --> 00:16:24,480 that's probably from some of the deep structures in the brain. 230 00:16:24,480 --> 00:16:27,760 Garth's research shows that the cannabinoid system protects 231 00:16:27,760 --> 00:16:31,720 the brain by regulating the other neurotransmitters within it. 232 00:16:33,280 --> 00:16:38,320 And the fact that it is so widespread is reflected in the range of sensations it brings. 233 00:16:41,120 --> 00:16:43,560 I have one spliff, nice and relaxed. 234 00:16:43,560 --> 00:16:45,560 Another one, more relaxed. 235 00:16:45,560 --> 00:16:47,600 By the third I might start giggling. 236 00:16:49,680 --> 00:16:54,160 I could do anything. Right now I could run in this sand. 237 00:16:54,160 --> 00:16:57,240 I could run in the sand from here to the pier and back, 238 00:16:57,240 --> 00:16:59,800 and probably just barely have a sweat. 239 00:17:02,280 --> 00:17:06,000 How to explain the coming up bit I guess... It's just... 240 00:17:06,000 --> 00:17:10,160 slipping in to a nice warm bath, I think is the best way to... 241 00:17:10,160 --> 00:17:13,440 At the end of the day, slipping into a nice warm bath, 242 00:17:13,440 --> 00:17:16,960 maybe a Jacuzzi going on, few bubbles, little yellow duck. 243 00:17:16,960 --> 00:17:20,600 It's just sort of that sort of like, "aaah..." 244 00:17:20,600 --> 00:17:26,000 That the cannabis plant should have evolved to produce a chemical 245 00:17:26,000 --> 00:17:28,320 that fits the highly complex receptors 246 00:17:28,320 --> 00:17:33,400 in our brain to cause these effects feels like a wild coincidence. 247 00:17:33,400 --> 00:17:36,320 But it's not as strange as you might think. 248 00:17:36,320 --> 00:17:42,080 There are hundreds of thousands of plant species and they create thousands of chemicals 249 00:17:42,080 --> 00:17:46,920 and it would be just remarkable if there wasn't one that didn't interact with the human brain. 250 00:17:46,920 --> 00:17:51,200 And they do, there's the opium poppy and the tobacco plant, 251 00:17:51,200 --> 00:17:53,640 and both of those act on the brain. 252 00:17:57,160 --> 00:18:02,760 These plants can affect our body chemistry because they're made of the same building blocks as we are. 253 00:18:02,760 --> 00:18:04,800 Cannabis is no exception. 254 00:18:11,120 --> 00:18:15,120 Whether you like it or not, each and every one of us 255 00:18:15,120 --> 00:18:18,880 is fundamentally wired to respond to cannabis. 256 00:18:21,800 --> 00:18:24,920 So has it simply been the victim of prejudice? 257 00:18:24,920 --> 00:18:27,560 How real is the dark side of cannabis? 258 00:18:37,720 --> 00:18:39,840 It's like I married cannabis, 259 00:18:39,840 --> 00:18:43,320 I never had a relationship of me own except with cannabis. 260 00:18:43,320 --> 00:18:45,880 That was my relationship... with cannabis. 261 00:18:45,880 --> 00:18:49,600 I did have chances in the past but I blew it because I married that thing. 262 00:18:49,600 --> 00:18:53,520 I feel powerless over this drug, I despise it. 263 00:18:53,520 --> 00:18:56,440 I gave up on life ten years ago. I thought... 264 00:18:56,440 --> 00:19:00,120 that's me doomed now because I can't stop this insidious addiction. 265 00:19:00,120 --> 00:19:06,080 John, not his real name, began his relationship with cannabis in his early 20s. 266 00:19:06,080 --> 00:19:08,760 It was 1991 and I got in with the wrong crowd, 267 00:19:08,760 --> 00:19:11,000 going to rave clubs and things. 268 00:19:11,000 --> 00:19:15,800 Some of the lads would be smoking spliffs and I wanted to fit in. 269 00:19:15,800 --> 00:19:20,800 Everybody else was doing it, even me mates round where I grew up, they were all doing it... 270 00:19:20,800 --> 00:19:27,480 and I thought, well, you know just to join the club like, and... 271 00:19:27,480 --> 00:19:29,960 But I got stuck with it, 272 00:19:29,960 --> 00:19:34,800 it started to rule my life and it was on my mind constantly, 273 00:19:34,800 --> 00:19:38,880 and I knew there was going to be a problem there. 274 00:19:38,880 --> 00:19:44,240 Now, every day of John's life is structured around cannabis. 275 00:19:44,240 --> 00:19:46,800 This morning I've been up since four o'clock 276 00:19:46,800 --> 00:19:50,240 and I've smoked about six, seven, eight spliffs, I don't know. 277 00:19:50,240 --> 00:19:56,520 My usual day is sad, but true... 278 00:19:56,520 --> 00:19:59,560 I'll get up in the morning whatever time it may be. 279 00:19:59,560 --> 00:20:01,640 I'll brew up, have a cup of tea, 280 00:20:01,640 --> 00:20:04,560 have a cup of coffee, spliff in between... 281 00:20:04,560 --> 00:20:08,280 Then I might go out for a walk round the park sometimes 282 00:20:08,280 --> 00:20:11,680 or feed the birds and then I'll have some more spliffs, cup of tea. 283 00:20:11,680 --> 00:20:14,240 Then come the evening time, seven o'clock, 284 00:20:14,240 --> 00:20:17,480 I might have a couple of glasses of wine, spliff, spliff. 285 00:20:17,480 --> 00:20:21,000 Then I'll roll a spliff which I'll smoke when I'm in bed. 286 00:20:21,000 --> 00:20:23,640 And that's Groundhog Day. 287 00:20:23,640 --> 00:20:26,200 And that happens most days in the week. 288 00:20:26,200 --> 00:20:29,440 And today is no exception. 289 00:20:29,440 --> 00:20:31,280 Right now... 290 00:20:31,280 --> 00:20:35,760 I have to be perfectly honest, I want youse to go for a bit while 291 00:20:35,760 --> 00:20:39,800 I skin up and make a spliff and then perhaps come back in half an hour. 292 00:20:51,680 --> 00:20:55,240 John can now barely imagine life without cannabis. 293 00:20:57,920 --> 00:21:02,720 I think to myself, if I stop, if I stop, how am I going to cope in the real world? 294 00:21:04,360 --> 00:21:07,680 That's how I feel. How am I going to function? 295 00:21:07,680 --> 00:21:11,120 How am I gonna mix with people? How am I gonna converse with people? 296 00:21:11,120 --> 00:21:15,200 I'm not used to doing that. I've spent 17 or 18 years puffing away on cannabis. 297 00:21:15,200 --> 00:21:17,400 It's like I'd have to start all over again... 298 00:21:17,400 --> 00:21:19,600 And I think it's too late now, it's too late. 299 00:21:19,600 --> 00:21:21,440 I've squandered my opportunities. 300 00:21:21,440 --> 00:21:25,120 I'm an addict, I loathe meself, I really do. 301 00:21:32,240 --> 00:21:36,680 Listening to John, he sounds like he needs cannabis to live. 302 00:21:36,680 --> 00:21:40,920 It's undoubtedly an addiction, but not in the same way as harder drugs. 303 00:21:42,400 --> 00:21:46,360 Heroin users that I see, there's no question really, that if they don't 304 00:21:46,360 --> 00:21:51,040 take the drug on a regular basis, they're going to be sick. 305 00:21:51,040 --> 00:21:53,760 They're going to get physical withdrawal symptoms 306 00:21:53,760 --> 00:21:55,000 and those symptoms 307 00:21:55,000 --> 00:21:58,680 are going to get worse and worse unless they take more of the drug. 308 00:21:58,680 --> 00:22:03,800 And that's I suppose, a classical definition of physical dependence. 309 00:22:03,800 --> 00:22:06,680 Cannabis is clearly much more subtle. 310 00:22:06,680 --> 00:22:13,280 It's not physical addiction, in that if they stop, they're not going to be physically ill. 311 00:22:13,280 --> 00:22:16,280 But if they stop they'll feel craving... 312 00:22:16,280 --> 00:22:18,840 a strong need to take the drug again. 313 00:22:18,840 --> 00:22:21,400 That is psychological addiction, 314 00:22:21,400 --> 00:22:28,280 and I don't think of it as a sort of lesser cousin to physical addiction, it's equally serious. 315 00:22:28,280 --> 00:22:35,120 So while it can be very damaging, addiction to cannabis is not a physical process in the body. 316 00:22:35,120 --> 00:22:40,040 Yet cannabis has been accused of permanently changing the brain in other ways. 317 00:22:44,320 --> 00:22:49,400 Does cannabis somehow make us more likely to abuse other, stronger, 318 00:22:49,400 --> 00:22:51,840 drugs such as cocaine or heroin? 319 00:22:56,320 --> 00:23:01,440 To answer that question, scientists have turned to rats. 320 00:23:02,800 --> 00:23:07,080 Their brain chemistry is similar to ours, but unlike humans, 321 00:23:07,080 --> 00:23:10,120 it's possible to give them cannabis in controlled amounts 322 00:23:10,120 --> 00:23:12,720 to see if this increases their taste for heroin. 323 00:23:14,400 --> 00:23:18,160 Dr Steve Goldberg has been measuring the effects. 324 00:23:18,160 --> 00:23:22,200 Well, in this room, we've got two groups of chambers, 325 00:23:22,200 --> 00:23:23,920 one either side. 326 00:23:23,920 --> 00:23:25,760 We're working with rats 327 00:23:25,760 --> 00:23:30,240 on this side that have had a previous exposure to cannabis. 328 00:23:30,240 --> 00:23:37,360 On the other side, the animals are control animals that have not had the exposure to cannabis. 329 00:23:37,360 --> 00:23:40,600 And we're looking at the differences between these two groups 330 00:23:40,600 --> 00:23:45,240 in terms of how much heroin they take 331 00:23:45,240 --> 00:23:47,720 and how hard they work for it. 332 00:23:47,720 --> 00:23:49,960 What does this individual rat have to do here? 333 00:23:49,960 --> 00:23:52,560 He's in a test situation, a light comes on, 334 00:23:52,560 --> 00:23:54,800 tells him that heroin's available. 335 00:23:54,800 --> 00:23:58,800 In order to get the heroin, he has to poke his nose through a hole, 336 00:23:58,800 --> 00:24:00,600 and he gets a dose of heroin. 337 00:24:00,600 --> 00:24:03,880 The flashing light is now him receiving a dose of heroin. 338 00:24:03,880 --> 00:24:05,600 He's just had a dose of heroin? Yes. 339 00:24:05,600 --> 00:24:06,960 Each group of rats, 340 00:24:06,960 --> 00:24:11,600 those who have been exposed to THC and the control group who haven't, 341 00:24:11,600 --> 00:24:13,760 have the opportunity to take heroin 342 00:24:13,760 --> 00:24:17,320 by poking their noses against a dispenser. 343 00:24:17,320 --> 00:24:19,600 The number of nose-pokes or doses 344 00:24:19,600 --> 00:24:23,120 that each rat takes is measured automatically. 345 00:24:23,120 --> 00:24:27,920 Steve then compares the results to see whether the past exposure to THC 346 00:24:27,920 --> 00:24:32,200 makes the rats more likely to take more frequent doses of heroin. 347 00:24:32,200 --> 00:24:36,800 So what results have you found for this rat and for other rats in his group? 348 00:24:36,800 --> 00:24:42,120 We found that rats that had exposure to cannabis in the past 349 00:24:42,120 --> 00:24:46,000 will work for and obtain more heroin each session 350 00:24:46,000 --> 00:24:50,880 than the control rats that didn't have the cannabis exposure. 351 00:24:50,880 --> 00:24:54,360 Actually, that's quite shocking that you found a connection 352 00:24:54,360 --> 00:24:56,160 between cannabis and heroin. 353 00:24:56,160 --> 00:25:01,000 The history of cannabis exposure produces a tolerance-like effect 354 00:25:01,000 --> 00:25:03,880 where they're less sensitive to the drug 355 00:25:03,880 --> 00:25:08,800 and that carries over to heroin, so they need a bigger dose to get the same effect. 356 00:25:11,000 --> 00:25:17,440 Tolerance just refers to the amount of a drug required to get you high when used repeatedly. 357 00:25:17,440 --> 00:25:20,520 It is not the same as addiction or desire for a drug, 358 00:25:20,520 --> 00:25:23,880 which is better measured by the effort made to get it. 359 00:25:23,880 --> 00:25:26,840 But if you then go on and in both groups 360 00:25:26,840 --> 00:25:32,520 and increase the number of times they have to nose-poke to get 361 00:25:32,520 --> 00:25:37,360 the heroin, in other words increase the price for getting heroin, 362 00:25:37,360 --> 00:25:38,960 then the two groups are the same. 363 00:25:40,440 --> 00:25:44,440 Steve gradually increases the number of nose-pokes required 364 00:25:44,440 --> 00:25:45,880 for one dose of heroin. 365 00:25:47,560 --> 00:25:52,240 As the workload rises, they reach a point, around 75 nose-pokes 366 00:25:52,240 --> 00:25:56,680 where both groups give up and stop working for the heroin. 367 00:25:59,960 --> 00:26:04,720 So with increased effort, the effect between the two groups disappeared. 368 00:26:04,720 --> 00:26:06,040 That's true. 369 00:26:06,040 --> 00:26:09,480 This shows there's no difference in the drive to get heroin 370 00:26:09,480 --> 00:26:14,320 between rats who have had cannabis and rats who have not. 371 00:26:14,320 --> 00:26:16,000 So what's the human implication? 372 00:26:16,000 --> 00:26:22,800 Basically, that you don't have enduring biological changes 373 00:26:22,800 --> 00:26:26,200 that occur because of the cannabis exposure 374 00:26:26,200 --> 00:26:30,440 that predetermine that you're going to go on and become 375 00:26:30,440 --> 00:26:33,680 addicted to other hard drugs. 376 00:26:33,680 --> 00:26:38,080 It says it's more of a social and historical thing that drives it. 377 00:26:38,080 --> 00:26:43,640 As ever, the picture is more complicated than a chemical switch in the brain. 378 00:26:43,640 --> 00:26:46,280 It seems it's more likely to be your peer group 379 00:26:46,280 --> 00:26:50,320 or life-stresses such as unemployment or the end of a relationship, 380 00:26:50,320 --> 00:26:53,360 that lead people from cannabis on to harder drugs. 381 00:26:55,200 --> 00:26:57,840 Yet there's another accusation levelled at cannabis. 382 00:26:57,840 --> 00:27:02,520 That it triggers one of the most severe of all mental disorders. 383 00:27:02,520 --> 00:27:05,600 Permanent psychosis, or schizophrenia. 384 00:27:09,680 --> 00:27:11,080 This is our family. 385 00:27:11,080 --> 00:27:13,640 This is Mark who's 28, 386 00:27:13,640 --> 00:27:21,520 Natalie who's 25 this is Paul who's 19 and this is his twin, Melissa. 387 00:27:21,520 --> 00:27:29,120 And, as far as we know, none of them suffer from any mental illness of any kind, 388 00:27:29,120 --> 00:27:35,400 so we think it's probably the cannabis which has caused the difficulties with Paul. 389 00:27:43,840 --> 00:27:47,520 Paul Floyd started smoking skunk, one of the most potent strains of cannabis, 390 00:27:47,520 --> 00:27:49,800 four years ago at the age of fifteen. 391 00:27:51,520 --> 00:27:55,280 After a year, he started to have strange experiences. 392 00:27:55,280 --> 00:27:57,360 'At first when I heard the voices, 393 00:27:57,360 --> 00:28:01,160 'I thought it was God talking to me, and I had delusions about God' 394 00:28:01,160 --> 00:28:04,280 and they were causing me to believe that I was Jesus 395 00:28:04,280 --> 00:28:07,520 and that I'd rise to heaven and things if I took it. 396 00:28:07,520 --> 00:28:11,760 I first started hearing them when I was on skunk and then they began 397 00:28:11,760 --> 00:28:16,240 to just start happening in normal every day life, as well. 398 00:28:16,240 --> 00:28:21,120 At first, Paul's parents were confused by his behaviour. 399 00:28:21,120 --> 00:28:22,440 It was a gradual change 400 00:28:22,440 --> 00:28:27,640 which we didn't really recognise for what it was, at the time. 401 00:28:27,640 --> 00:28:30,960 So there were things like staring very intently 402 00:28:30,960 --> 00:28:35,320 at members of the family, other people, weren't there? 403 00:28:35,320 --> 00:28:41,440 Um, laughing to himself when there was nothing to laugh about. 404 00:28:41,440 --> 00:28:46,600 And some strange sort of body posturing sometimes, 405 00:28:46,600 --> 00:28:51,400 it's quite hard to describe, like some strange sort of gestures. 406 00:28:51,400 --> 00:28:56,040 Almost boxing at times, wasn't it? Yes. 407 00:28:56,040 --> 00:28:57,760 Quite peculiar, really. 408 00:28:59,520 --> 00:29:03,640 After that, Paul's behaviour changed rapidly, as over time, 409 00:29:03,640 --> 00:29:06,600 twelve separate voices appeared and gave him instructions. 410 00:29:07,840 --> 00:29:10,080 'They used to tell me to throw things away 411 00:29:10,080 --> 00:29:12,760 'like I'd throw away my CD collection.' 412 00:29:12,760 --> 00:29:15,920 They were saying I should bring about the downfall of, like, 413 00:29:15,920 --> 00:29:19,440 the music industry by throwing CDs away. 414 00:29:19,440 --> 00:29:21,640 Other people would follow 415 00:29:21,640 --> 00:29:25,680 through some sort of mind link or something. 416 00:29:27,560 --> 00:29:31,800 Sometimes the voices would speak to Paul through the radio or television. 417 00:29:31,800 --> 00:29:35,520 From programmes like Coronation Street, the characters would say 418 00:29:35,520 --> 00:29:38,320 to clean things. 419 00:29:38,320 --> 00:29:43,640 I had to buy a lot of cleaning products and they had to be matching in every room of the house, 420 00:29:43,640 --> 00:29:50,480 matching colours, he got quite distressed if they weren't the same colours in each room. 421 00:29:50,480 --> 00:29:56,480 I've got a shed full of mops and buckets that he persuaded me to buy when he was 422 00:29:56,480 --> 00:29:59,840 very fixated on cleaning. 423 00:29:59,840 --> 00:30:05,720 Yet even at this point, Sheila and Dave didn't connect Paul's behaviour with cannabis... 424 00:30:05,720 --> 00:30:08,240 because they didn't even know he was smoking it. 425 00:30:08,240 --> 00:30:12,680 Innocently, every week, we would give him an allowance... 426 00:30:12,680 --> 00:30:16,640 Even then we didn't make the link between how he was behaving 427 00:30:16,640 --> 00:30:20,720 and the fact that he smoking that necessarily, did we? 428 00:30:20,720 --> 00:30:23,360 I know that sounds probably a bit naive now. 429 00:30:31,120 --> 00:30:34,960 It was only once Sheila and Dave took Paul to a psychiatrist 430 00:30:34,960 --> 00:30:38,360 that they connected his problems with cannabis. 431 00:30:38,360 --> 00:30:40,480 Paul was diagnosed with schizophrenia, 432 00:30:40,480 --> 00:30:45,800 and prescribed anti-psychotic medication which he may have to take for the rest of his life. 433 00:30:47,360 --> 00:30:52,440 But although the connection between Paul's cannabis use and schizophrenia may seems clear... 434 00:30:52,440 --> 00:30:55,840 it's extremely hard to demonstrate. 435 00:30:59,160 --> 00:31:02,600 Proving the link between cannabis and psychosis is never going to be easy. 436 00:31:02,600 --> 00:31:05,080 It's a bit like a chicken and the egg situation. 437 00:31:05,080 --> 00:31:07,120 Does the drug cause mental illness, 438 00:31:07,120 --> 00:31:11,000 or is it that people with mental illness in some way seek out cannabis? 439 00:31:13,520 --> 00:31:18,040 'One person trying to untangle this puzzle is Dr Cathy Fernandes.' 440 00:31:18,040 --> 00:31:20,040 Tell me, how are you studying the link 441 00:31:20,040 --> 00:31:22,040 between cannabis and schizophrenia? 442 00:31:22,040 --> 00:31:23,720 What we're really interested in 443 00:31:23,720 --> 00:31:25,600 is the long-lasting effects of cannabis. 444 00:31:25,600 --> 00:31:29,600 We're using mice to do this because we can control when they have the cannabis, 445 00:31:29,600 --> 00:31:31,440 what age they have it, and for how long. 446 00:31:31,440 --> 00:31:35,000 So this is the centre of your experiment. What goes on here? 447 00:31:35,000 --> 00:31:38,080 This is a behavioural task called the Morris Water Maze. 448 00:31:38,080 --> 00:31:42,320 It's a spatial memory task, so we are looking at differences in memory and learning. 449 00:31:42,320 --> 00:31:45,480 They have to learn the location of a hidden platform in the pool, 450 00:31:45,480 --> 00:31:50,520 so here we have the platform that's hidden below the level of the water. 451 00:31:50,520 --> 00:31:52,960 The water's sort of opaque, isn't it? 452 00:31:52,960 --> 00:31:56,840 That's right, it hides the platform under the water. 453 00:31:56,840 --> 00:32:01,080 So really they have to learn to navigate by using cues or objects outside the room, 454 00:32:01,080 --> 00:32:02,680 so if you look around the room, 455 00:32:02,680 --> 00:32:06,840 we have various objects outside the pool and these help the animals to navigate, 456 00:32:06,840 --> 00:32:10,720 so when they reach the platform, they can look up and try and locate themselves. 457 00:32:10,720 --> 00:32:14,320 So we're looking at how fast and how quickly they reach the platform, 458 00:32:14,320 --> 00:32:18,960 and whether they can swim in a straight direction when they reach the platform. 459 00:32:20,480 --> 00:32:25,600 So Cathy took two groups of mice. The first group were exposed to THC 460 00:32:25,600 --> 00:32:31,360 when they were juveniles, equivalent to age 10 to 15 in humans. 461 00:32:31,360 --> 00:32:35,000 So we gave them something equivalent to two or three joints a day... 462 00:32:35,000 --> 00:32:37,880 And we treated them for two weeks, when they were young, 463 00:32:37,880 --> 00:32:42,080 then we stopped their drug treatment we waited for them to grow up, until they were adults, 464 00:32:42,080 --> 00:32:43,400 about two months later. 465 00:32:43,400 --> 00:32:47,560 so now we're ready to test them, they're drug free, don't have any THC on board now. 466 00:32:49,600 --> 00:32:51,200 'The first mouse goes in.' 467 00:32:54,720 --> 00:32:57,560 But what can a swimming mouse tell you about psychosis? 468 00:32:57,560 --> 00:33:02,640 We don't know if any normal mice would ever have schizophrenia. 469 00:33:02,640 --> 00:33:05,280 But we do know there are some very important core features 470 00:33:05,280 --> 00:33:07,920 of schizophrenia we can study in animals. 471 00:33:07,920 --> 00:33:10,360 One of those features is a memory impairment. 472 00:33:10,360 --> 00:33:14,040 We can look at that directly in mice, using this sort of task here, 473 00:33:14,040 --> 00:33:20,040 we can pick up differences in memory after giving the mice cannabis. 474 00:33:20,040 --> 00:33:24,800 You have to say, he doesn't look as if he's remembered the location of the platform. 475 00:33:24,800 --> 00:33:30,080 You can see he's swimming around but really not finding the location of the platform. 476 00:33:30,080 --> 00:33:33,800 If he does find it, you'd have to conclude that it was by chance, I think. 477 00:33:33,800 --> 00:33:39,280 That's right. He has already been swimming for a while so now I will guide him to the platform location. 478 00:33:41,960 --> 00:33:43,440 And there he is. 479 00:33:59,720 --> 00:34:04,360 'Cathy repeats the memory test with a squad of 12 mice, 480 00:34:05,880 --> 00:34:10,080 'before moving on to a second group of mice who received THC 481 00:34:10,080 --> 00:34:15,240 'when they were slightly older, equivalent to teenagers aged 15 and over.' 482 00:34:24,560 --> 00:34:25,680 And straight there. 483 00:34:25,680 --> 00:34:32,280 That's right, so you see a much straighter, a more directed action to the one he found it much quicker. 484 00:34:33,840 --> 00:34:38,320 'Once more twelve mice are tested before Cathy compares the results 485 00:34:38,320 --> 00:34:41,520 'of the two groups against a control group.' 486 00:34:46,200 --> 00:34:50,000 So this is the track data that we have from the computer system that we use, 487 00:34:50,000 --> 00:34:53,360 it's able to give us really accurate recording and measures... 488 00:34:53,360 --> 00:34:56,400 not just the time it takes for the mice to reach the platform, 489 00:34:56,400 --> 00:35:00,080 but also how far they've swam, the distance they've swam. 490 00:35:00,080 --> 00:35:02,920 So the first mice we have here, these are the black mice 491 00:35:02,920 --> 00:35:05,880 that received THC when they were very young adolescents, 492 00:35:05,880 --> 00:35:09,600 and if you look at the track, they're really swimming all over the pool, 493 00:35:09,600 --> 00:35:13,560 not in a very straight pattern, and taking a long time to reach the location. 494 00:35:13,560 --> 00:35:19,160 So if we now compare to the mice who received the THC when they were teenagers or young adults, 495 00:35:19,160 --> 00:35:22,560 you can see they really have learnt the location of the platform, 496 00:35:22,560 --> 00:35:26,640 so clearly giving THC when you're an older age doesn't seem to cause an impairment. 497 00:35:26,640 --> 00:35:29,120 Can you quantify the difference between the two? 498 00:35:29,120 --> 00:35:31,720 We do find a very large significant difference, 499 00:35:31,720 --> 00:35:36,560 as much as 25% deficit in the THC-treated young adolescent mice, 500 00:35:36,560 --> 00:35:40,200 so we really are fairly sure that there's a strong impact in giving 501 00:35:40,200 --> 00:35:45,760 THC to young adolescents, there's a lasting effect on their memory performance when they're adult. 502 00:35:45,760 --> 00:35:50,400 Could you translate that to human development? 503 00:35:50,400 --> 00:35:54,480 We think that would indicate the vulnerable group are children 504 00:35:54,480 --> 00:36:00,160 under 15 receiving high doses or concentrations of THC repeatedly. 505 00:36:00,160 --> 00:36:03,040 It's a worrying trend because the number of children 506 00:36:03,040 --> 00:36:06,000 who are now taking cannabis is really on the rise. 507 00:36:06,000 --> 00:36:10,360 So we know that in the UK at least, 40% of 15-year-olds have tried cannabis already, 508 00:36:10,360 --> 00:36:16,040 and this is the point at which they might be developmentally vulnerable to the effects of THC. 509 00:36:16,040 --> 00:36:20,040 Cathy's research implies that just a few years 510 00:36:20,040 --> 00:36:24,080 can make a critical difference to how cannabis affects your brain. 511 00:36:24,080 --> 00:36:28,040 But for schizophrenia to develop is rare. 512 00:36:28,040 --> 00:36:32,040 The likelihood of developing schizophrenia in your lifetime is 1%. 513 00:36:32,040 --> 00:36:35,120 Occasional cannabis use can raise this to 2% 514 00:36:35,120 --> 00:36:39,440 while heavy use might raise the lifetime risk to 6%. 515 00:36:49,800 --> 00:36:56,040 The problem is, anyone using cannabis won't know whether they are vulnerable until it's too late. 516 00:36:56,040 --> 00:37:00,480 Now Paul is trying to rebuild his life. 517 00:37:00,480 --> 00:37:02,120 We're immensely proud of him. 518 00:37:02,120 --> 00:37:06,440 The way he's got through things, he's back at college... 519 00:37:06,440 --> 00:37:12,440 We're really, really proud of him, he's coped amazingly well with it all. 520 00:37:18,720 --> 00:37:23,080 I'm hoping to learn to drive and possibly go to uni and study further, 521 00:37:23,080 --> 00:37:26,480 and I'd like to go to Africa and build a school and things like that. 522 00:37:30,560 --> 00:37:34,960 Despite stopping smoking cannabis and starting medication, 523 00:37:34,960 --> 00:37:38,480 the voices in Paul's head have not left him entirely. 524 00:37:40,920 --> 00:37:43,880 Now I hear the voice of a girl I used to know - 525 00:37:43,880 --> 00:37:45,880 I didn't know her very well, 526 00:37:45,880 --> 00:37:48,200 but for some reason she stuck in my head. 527 00:37:48,200 --> 00:37:50,920 I hear her voice most of the day 528 00:37:50,920 --> 00:37:54,800 and before I go to sleep is the worst time. 529 00:37:54,800 --> 00:37:58,720 Sometimes she's told me to commit suicide and things 530 00:37:58,720 --> 00:38:01,440 but I tend to just ignore that. 531 00:38:01,440 --> 00:38:04,120 The thought that he will always be hearing that 532 00:38:04,120 --> 00:38:06,120 is really difficult to contemplate 533 00:38:06,120 --> 00:38:09,080 because I can hardly imagine what that must be like. 534 00:38:11,200 --> 00:38:13,720 Paul's story shows what long-term effects 535 00:38:13,720 --> 00:38:16,240 cannabis might have on the human brain. 536 00:38:20,120 --> 00:38:23,400 Now, research into the short-term effects of using cannabis 537 00:38:23,400 --> 00:38:26,680 suggests that there may be a link with schizophrenia here too. 538 00:38:30,640 --> 00:38:34,760 The first studies of the immediate effects of THC on the human brain 539 00:38:34,760 --> 00:38:37,760 are now being made by Dr Zerrin Atakan. 540 00:38:37,760 --> 00:38:40,840 I really want to see how cannabis does its effect, 541 00:38:40,840 --> 00:38:42,680 especially in the brain, 542 00:38:42,680 --> 00:38:46,960 because this is the most widely used drug in the world 543 00:38:46,960 --> 00:38:49,360 and we still know not too much about it. 544 00:38:49,360 --> 00:38:52,240 Especially how it works in the brain. 545 00:38:52,240 --> 00:38:55,920 Zerrin was particularly interested in how THC can affect 546 00:38:55,920 --> 00:39:00,360 the brain's internal control over your behaviour and inner thoughts. 547 00:39:00,360 --> 00:39:03,160 As you know, when people smoke cannabis 548 00:39:03,160 --> 00:39:06,040 sometimes they can have, some of them, 549 00:39:06,040 --> 00:39:08,680 have difficulty in controlling their behaviour, 550 00:39:08,680 --> 00:39:11,520 and that's why we chose a task that could measure this. 551 00:39:11,520 --> 00:39:14,360 And the task is called response inhibition, 552 00:39:14,360 --> 00:39:16,760 or how you stop yourself from doing something, 553 00:39:16,760 --> 00:39:18,400 or how you put the brakes on. 554 00:39:18,400 --> 00:39:20,680 OK. Can you show me the task? Yeah. 555 00:39:20,680 --> 00:39:26,920 When volunteer lies in the scanner, this is what he sees. 556 00:39:26,920 --> 00:39:30,200 He sees an arrow pointing right or left, 557 00:39:30,200 --> 00:39:35,280 and he is asked to press the button right or left accordingly. 558 00:39:35,280 --> 00:39:40,120 And then occasionally there will be an arrow pointing upwards, 559 00:39:40,120 --> 00:39:43,080 and he is asked not to press the button. 560 00:39:43,080 --> 00:39:45,200 So in a sense he is asked to do nothing? 561 00:39:45,200 --> 00:39:49,120 He is asked to stop himself from pressing the button 562 00:39:49,120 --> 00:39:54,200 and this was the particular bit of the task that we were interested in. 563 00:39:54,200 --> 00:39:56,360 And this is how we put the brakes on... 564 00:39:56,360 --> 00:39:58,680 So I guess that sort of braking 565 00:39:58,680 --> 00:40:02,600 is the sort of control over behaviour that we do all the time. Yeah. 566 00:40:02,600 --> 00:40:08,000 So Zerrin gave this task to volunteers, inside a brain scanner. 567 00:40:08,000 --> 00:40:13,480 Each of them had received THC equivalent to smoking one joint. 568 00:40:13,480 --> 00:40:17,720 She then repeated the experiment with a placebo for comparison. 569 00:40:19,560 --> 00:40:23,160 What she was looking for was the brain activity in each group 570 00:40:23,160 --> 00:40:27,480 as they tried not to press the button in response to the up arrow. 571 00:40:27,480 --> 00:40:31,000 This is the average of 15 volunteers. 572 00:40:31,000 --> 00:40:33,840 And this is the placebo condition, 573 00:40:33,840 --> 00:40:37,320 basically this is the normal situation. 574 00:40:37,320 --> 00:40:40,160 This is the normal brain responding to that task. 575 00:40:40,160 --> 00:40:44,680 As you can see certain areas are looking red there 576 00:40:44,680 --> 00:40:49,120 which are activated, that is the pre-frontal cortex... 577 00:40:49,120 --> 00:40:52,680 and this is what you would expect in a normal situation, 578 00:40:52,680 --> 00:40:57,400 when we are stopping yourself from doing something. 579 00:40:57,400 --> 00:41:01,640 This is the average of again 15 people 580 00:41:01,640 --> 00:41:04,320 this time who have taken THC, cannabis. 581 00:41:04,320 --> 00:41:08,720 And what you see, very clearly, that in fact the normal areas 582 00:41:08,720 --> 00:41:11,760 are not working, there's no activity. 583 00:41:11,760 --> 00:41:15,960 Zerrin believes that the inactivation of these frontal areas of the brain 584 00:41:15,960 --> 00:41:18,080 which interpret our surroundings 585 00:41:18,080 --> 00:41:21,800 might explain some effects of cannabis such as paranoia. 586 00:41:21,800 --> 00:41:25,600 If your brakes aren't on, you might misinterpret 587 00:41:25,600 --> 00:41:29,440 or you could maybe see a shadow or hear a sound. 588 00:41:29,440 --> 00:41:33,360 Normally you would say this is just a branch or this is just the wind, 589 00:41:33,360 --> 00:41:36,560 but if you already misinterpreting what is going on, 590 00:41:36,560 --> 00:41:41,040 you're not putting the brakes on, you might interpret that as someone following you. 591 00:41:41,040 --> 00:41:44,560 So this is showing how cannabis affects the brain. 592 00:41:44,560 --> 00:41:47,120 And would that be a similar way 593 00:41:47,120 --> 00:41:50,960 in which the brain of a schizophrenic might be working? 594 00:41:50,960 --> 00:41:53,320 Yes, there are similarities, I agree, 595 00:41:53,320 --> 00:41:57,880 especially if you think that cannabis can affect people 596 00:41:57,880 --> 00:42:01,240 in a way that they become suspicious 597 00:42:01,240 --> 00:42:05,480 and same thing you see also in people with schizophrenia, 598 00:42:05,480 --> 00:42:08,840 that they can be over-suspicious about their environment, 599 00:42:08,840 --> 00:42:13,160 and again we know that this area is a suspect area 600 00:42:13,160 --> 00:42:16,720 in severe mental illness like schizophrenia. 601 00:42:18,800 --> 00:42:21,040 Zerrin's research is preliminary 602 00:42:21,040 --> 00:42:24,600 but implies that when the brain is under the influence of THC, 603 00:42:24,600 --> 00:42:28,160 the effects can be similar to those seen in schizophrenia. 604 00:42:28,160 --> 00:42:31,080 It reinforces the idea that smoking cannabis 605 00:42:31,080 --> 00:42:34,440 can, in a small number of cases, trigger the condition. 606 00:42:46,080 --> 00:42:49,280 But cannabis has another face entirely. 607 00:42:49,280 --> 00:42:52,720 Here in California, people are using it to improve their health. 608 00:43:01,480 --> 00:43:04,920 Following a legal statute called the Compassionate Use Act, 609 00:43:04,920 --> 00:43:07,760 passed in 1996, those with a medical problem 610 00:43:07,760 --> 00:43:12,000 can obtain cannabis from a high street dispensary. 611 00:43:13,040 --> 00:43:16,280 There's quite a strong smell of cannabis. 612 00:43:17,680 --> 00:43:19,600 Oh look, look. 613 00:43:21,680 --> 00:43:24,680 These are all edible forms of cannabis, I guess - 614 00:43:24,680 --> 00:43:29,160 green label cakes, single shot cakes, triple-X cakes, 615 00:43:29,160 --> 00:43:31,520 vegan chocolate chip, vanilla brownie, 616 00:43:31,520 --> 00:43:36,200 down here various forms of soda, tea and so forth, 617 00:43:36,200 --> 00:43:42,040 chocolate chip, vanilla, rich berries, mango, 618 00:43:42,040 --> 00:43:44,120 all cannabis ice-cream. 619 00:43:44,120 --> 00:43:47,120 There's two condensed buds of cannabis. 620 00:43:47,120 --> 00:43:50,600 Oh, and look - a joint itself. 621 00:43:50,600 --> 00:43:54,080 And here's the centre of the operation, 622 00:43:54,080 --> 00:43:57,880 and lo and behold it's a sort of bank of cannabis there. 623 00:44:04,040 --> 00:44:07,400 One of the people making medical use of marijuana, 624 00:44:07,400 --> 00:44:10,080 as it's known in the US, is Allison Stanley. 625 00:44:10,080 --> 00:44:12,040 When I started to look into this 626 00:44:12,040 --> 00:44:18,040 I thought "No way, this is just another gimmick, 627 00:44:18,040 --> 00:44:21,280 "this is for potheads, this is for druggies," you know, 628 00:44:21,280 --> 00:44:25,560 "I don't want to get addicted". I wasn't for it in the beginning. 629 00:44:25,560 --> 00:44:28,640 But after exhausting all conventional treatments, 630 00:44:28,640 --> 00:44:30,640 she had to reconsider. 631 00:44:30,640 --> 00:44:33,880 I was in a very serious car accident last summer, 632 00:44:33,880 --> 00:44:38,760 where I was shoved under the dashboard, and I had a detached colon as a result of it, 633 00:44:38,760 --> 00:44:44,320 I had a knee injury, I have a shoulder injury, and I'm going through multiple surgeries. 634 00:44:44,320 --> 00:44:48,320 And my doctors weren't able to address the pain issue, 635 00:44:48,320 --> 00:44:51,160 or the lack of sleep that I was getting. 636 00:44:51,160 --> 00:44:55,840 I keep it in my bedroom, and only in my bedroom. 637 00:44:55,840 --> 00:45:00,960 All you do is insert this... and you do this. 638 00:45:00,960 --> 00:45:03,960 It helps with the pain, definitely, 639 00:45:03,960 --> 00:45:06,160 and it definitely helps me sleep at night. 640 00:45:07,560 --> 00:45:09,280 So it's brought life back to me. 641 00:45:10,320 --> 00:45:13,720 Elsewhere in Los Angeles, Tom is using medical marijuana 642 00:45:13,720 --> 00:45:15,880 for entirely different reasons. 643 00:45:15,880 --> 00:45:19,600 I smoke medical marijuana, cannabis, because it makes me relaxed. 644 00:45:19,600 --> 00:45:24,240 It helps me deal with day-to-day stress in life. 645 00:45:24,240 --> 00:45:26,160 It really helps me with anxiety, 646 00:45:26,160 --> 00:45:28,920 and I have incredible anxiety attacks 647 00:45:28,920 --> 00:45:32,400 where I just get stressed out, I can't deal with reality. 648 00:45:32,400 --> 00:45:37,080 Previously I had a prescription to anxiety drugs 649 00:45:37,080 --> 00:45:41,120 and those anxiety drugs, taking them so much 650 00:45:41,120 --> 00:45:43,760 and it was just really, really bad for me. 651 00:45:45,360 --> 00:45:47,360 It was the strain of the business world 652 00:45:47,360 --> 00:45:49,760 that drove Tom to find a release. 653 00:45:49,760 --> 00:45:52,480 The corporate world made me stressed, 654 00:45:52,480 --> 00:45:54,080 extremely stressed. 655 00:45:55,680 --> 00:45:56,720 Totally stressed. 656 00:45:56,720 --> 00:45:59,760 I am so happy I'm out of the corporate world, it's amazing. 657 00:46:00,800 --> 00:46:02,440 TOM COUGHS 658 00:46:02,440 --> 00:46:05,760 I'm not very social when I don't smoke marijuana. 659 00:46:05,760 --> 00:46:08,720 I like smoking marijuana... It calms me down. 660 00:46:08,720 --> 00:46:11,200 I just feel totally at ease, everybody knows me - 661 00:46:11,200 --> 00:46:13,840 "Smoke a little marijuana, Tom, you'll be great. 662 00:46:13,840 --> 00:46:16,440 "Everything's gonna be fine, you know. Take a hit!" 663 00:46:19,920 --> 00:46:26,200 Usually I'll do that, just smoking large quantities with other patients 664 00:46:26,200 --> 00:46:29,960 and we're all medicating together, collectively, 665 00:46:29,960 --> 00:46:34,560 and so we'll do that in more of a social environment 666 00:46:34,560 --> 00:46:37,000 where we're medicating, yet being social. 667 00:46:37,000 --> 00:46:40,000 So it's not that we're socially smoking the marijuana, 668 00:46:40,000 --> 00:46:43,400 we're medicating it for use, but we're doing it together. 669 00:46:44,640 --> 00:46:48,760 For Tom and Alison, obtaining cannabis is straightforward. 670 00:46:48,760 --> 00:46:52,720 They go about it the same way as you would obtain any other medicine, 671 00:46:52,720 --> 00:46:54,240 by going to a doctor. 672 00:46:55,880 --> 00:46:58,320 Alan, how does your practice work here? 673 00:46:58,320 --> 00:47:00,720 It works just like my internal medicine office, 674 00:47:00,720 --> 00:47:04,000 patients call in, they come in, they're evaluated by myself, 675 00:47:04,000 --> 00:47:05,000 I make a diagnosis 676 00:47:05,000 --> 00:47:08,480 and if appropriate I recommend medical cannabis for them. 677 00:47:08,480 --> 00:47:11,120 What are some of the complaints people come in with? 678 00:47:11,120 --> 00:47:14,960 The common complaints are either Chronic Pain Syndrome of some sort, 679 00:47:14,960 --> 00:47:18,280 and that can be a specific back or hip injury, 680 00:47:18,280 --> 00:47:20,800 anxiety's a very common one, 681 00:47:20,800 --> 00:47:22,840 depression, insomnia. 682 00:47:22,840 --> 00:47:28,160 What proportion would you say come in with the common mental health disorders, anxiety and depression? 683 00:47:28,160 --> 00:47:31,000 Probably anxiety, depression represent about half the patients. 684 00:47:31,000 --> 00:47:34,680 As many as that. Couldn't that make their problems worse? 685 00:47:34,680 --> 00:47:36,760 If somebody has mild daily anxiety, 686 00:47:36,760 --> 00:47:39,760 they're just trying to feel 25% better. 687 00:47:39,760 --> 00:47:43,520 Is it reasonable for them to try using a little plant extract, 688 00:47:43,520 --> 00:47:47,360 if you look at it that way, it's kind of hard to argue against. 689 00:47:47,360 --> 00:47:51,840 It's just it's been built up as being such a scary, scary thing. 690 00:47:51,840 --> 00:47:53,240 And it just isn't. 691 00:47:53,240 --> 00:47:56,960 What if I walked into your practice on a Monday morning, 692 00:47:56,960 --> 00:47:58,800 and I sat down and I said, 693 00:47:58,800 --> 00:48:02,720 "Dr Frankel, my mood's good, I don't have any pain, 694 00:48:02,720 --> 00:48:07,320 "but you know what, I just can't seem get over writer's block. 695 00:48:07,320 --> 00:48:10,240 "I'm sitting at my PC and I'm just not getting it 696 00:48:10,240 --> 00:48:12,600 "and I've been stuck for a week, 697 00:48:12,600 --> 00:48:15,400 "can you give me anything for my creativity?" 698 00:48:17,520 --> 00:48:21,400 I know that people would disagree with it, with me for saying this, 699 00:48:21,400 --> 00:48:25,840 but to me that's a reasonable, I think, human right, 700 00:48:25,840 --> 00:48:29,680 to try and improve your situation by doing constructive things 701 00:48:29,680 --> 00:48:31,520 under a professional's care. 702 00:48:31,520 --> 00:48:33,400 And could that include cannabis? 703 00:48:33,400 --> 00:48:35,360 Yes. In my opinion. 704 00:48:36,520 --> 00:48:41,240 Would it be fair for me to think that it doesn't really matter 705 00:48:41,240 --> 00:48:44,560 what people come in with, if they're the right age, 706 00:48:44,560 --> 00:48:49,440 they've got general pain or psychological problems, 707 00:48:49,440 --> 00:48:52,880 the answer from Dr Frankel's point of view is cannabis. 708 00:48:52,880 --> 00:48:56,320 Yes, if I were a cardiologist and patients were coming into me, 709 00:48:56,320 --> 00:48:58,920 they'd leave with cardiology medications. 710 00:48:58,920 --> 00:49:02,000 If I'm a cannabiologist and they're coming to me cos they've tried 711 00:49:02,000 --> 00:49:03,920 so many other things and they've failed, 712 00:49:03,920 --> 00:49:07,240 the likelihood is they'll leave with a cannabis recommendation. 713 00:49:11,920 --> 00:49:14,600 While the system in place here runs smoothly enough, 714 00:49:14,600 --> 00:49:17,040 it worries me that it's open to abuse, 715 00:49:17,040 --> 00:49:19,880 but more than that, it's an experiment 716 00:49:19,880 --> 00:49:22,720 that is being stretched beyond any available evidence. 717 00:49:24,120 --> 00:49:29,400 I don't really have a problem buying into the view 718 00:49:29,400 --> 00:49:33,040 of cannabis as being connected to treating pain, 719 00:49:33,040 --> 00:49:35,720 you know, that seems to be pretty clear. 720 00:49:35,720 --> 00:49:39,160 Whether we can make a much greater leap of faith 721 00:49:39,160 --> 00:49:43,400 towards buying into the treatment of common mental disorders 722 00:49:43,400 --> 00:49:46,680 such as anxiety and depression with cannabis 723 00:49:46,680 --> 00:49:49,920 is a bigger order and I'm still pretty sceptical about that. 724 00:49:51,160 --> 00:49:52,800 To add to the uncertainty, 725 00:49:52,800 --> 00:49:56,520 although medical cannabis is approved by California state law, 726 00:49:56,520 --> 00:49:59,160 it's still illegal under federal law, 727 00:49:59,160 --> 00:50:02,600 so even here where residents have voted for medical cannabis, 728 00:50:02,600 --> 00:50:05,520 the relationship is still a confused one. 729 00:50:07,200 --> 00:50:12,800 It's a surprising situation for a plant that's been with us so long. 730 00:50:12,800 --> 00:50:15,720 Other plant-based drugs with medical uses, 731 00:50:15,720 --> 00:50:18,000 such as aspirin, cocaine and heroin, 732 00:50:18,000 --> 00:50:20,600 have all been exploited for their full benefits. 733 00:50:20,600 --> 00:50:22,840 But cannabis lags behind. 734 00:50:23,880 --> 00:50:27,600 In fact only now is the world's first legal medicine 735 00:50:27,600 --> 00:50:30,000 based on the cannabis plant being produced, 736 00:50:30,000 --> 00:50:32,160 deep in the English countryside. 737 00:50:32,160 --> 00:50:34,320 I'm going there for a rare glimpse. 738 00:50:35,640 --> 00:50:38,120 Even though it's all done completely legally, 739 00:50:38,120 --> 00:50:40,360 with the permission of the Home Office, 740 00:50:40,360 --> 00:50:44,680 the security arrangements means the exact location has to remain a secret. 741 00:50:44,680 --> 00:50:47,120 That means we're gonna have to turn the camera off. 742 00:50:49,480 --> 00:50:53,040 Come on through, John. Thank you. So this is it? 743 00:50:53,040 --> 00:50:56,360 This is it, you can see here, one of our growing areas. 744 00:50:56,360 --> 00:50:59,840 And a fairly wide selection of plants. 745 00:50:59,840 --> 00:51:02,120 Come on in, have a look. Thank you. 746 00:51:02,120 --> 00:51:03,920 Gosh, there's loads of it! 747 00:51:09,880 --> 00:51:11,600 How many plants have we got here? 748 00:51:11,600 --> 00:51:15,200 There's about 5,000 plants here and every year we grow about 30,000. 749 00:51:15,200 --> 00:51:19,520 And how much volume of cannabis would this produce per year? 750 00:51:19,520 --> 00:51:23,360 The payload, the botanical raw materials it's called, about a tonne. 751 00:51:23,360 --> 00:51:24,800 Gosh. 752 00:51:24,800 --> 00:51:28,040 To turn it into a saleable pain relief medicine, 753 00:51:28,040 --> 00:51:29,680 the cannabis is first dried. 754 00:51:30,840 --> 00:51:37,160 Each and every plant is a clone, so that the exact properties are known and consistent. 755 00:51:37,160 --> 00:51:38,493 It's like hanging out the washing. 756 00:51:38,528 --> 00:51:40,620 let's go in here now. 757 00:51:43,760 --> 00:51:45,600 After you. 758 00:51:45,600 --> 00:51:48,160 We need to get into this kit I'm afraid. 759 00:51:53,840 --> 00:51:56,960 Next it is milled and heated... . 760 00:51:56,960 --> 00:52:01,240 So we See raw material, will be 761 00:52:01,240 --> 00:52:02,840 put into the 762 00:52:02,840 --> 00:52:07,960 mill and its grounded down to particals of about a millimeter. 763 00:52:07,960 --> 00:52:10,200 At this stage nothing's wasted... 764 00:52:10,200 --> 00:52:13,360 Yes, it all goes in there exactly. 765 00:52:13,360 --> 00:52:17,400 The plant material is reduced to a concentrate And then it ends up in 766 00:52:17,400 --> 00:52:23,040 here, spinning down to about 60 degrees and all the liquid just evaporates away. 767 00:52:23,040 --> 00:52:26,560 To give you an idea of the sort of material it is, 768 00:52:26,560 --> 00:52:28,880 it's sort of treacle like. 769 00:52:28,880 --> 00:52:32,160 It's quite sticky. It really is quite sticky, and that makes it 770 00:52:32,160 --> 00:52:34,080 quite hard to work with therefore. 771 00:52:34,080 --> 00:52:35,760 Let's have a look at that. 772 00:52:35,760 --> 00:52:36,880 Oh, gosh. 773 00:52:38,320 --> 00:52:43,200 The final product is a liquid which the patient sprays into their mouth 774 00:52:43,200 --> 00:52:46,000 so removing the need for harmful smoking. 775 00:52:46,000 --> 00:52:49,080 Yet, despite this meticulous processing, 776 00:52:49,080 --> 00:52:51,360 it's still not widely available. 777 00:52:51,360 --> 00:52:53,160 It's not exactly taking it's place 778 00:52:53,160 --> 00:52:55,200 in the pharmacies across the country. 779 00:52:55,200 --> 00:52:57,640 Is that because the effects are quite weak? 780 00:52:57,640 --> 00:52:59,960 No, they're not weak at all. 781 00:52:59,960 --> 00:53:03,720 I think that cannabis wouldn't have survived over the millennia 782 00:53:03,720 --> 00:53:07,880 as a medicinal...entity if it had been weak. 783 00:53:07,880 --> 00:53:09,960 And cannabis-medicines aren't weak. 784 00:53:09,960 --> 00:53:12,840 It's simply that we're dealing with a group of patients 785 00:53:12,840 --> 00:53:16,480 who have tried all the standard medicines and haven't responded 786 00:53:16,480 --> 00:53:19,960 before they ever come into the medical clinical trials with this drug. 787 00:53:19,960 --> 00:53:22,840 Dealing with outcome measures which are really vague - 788 00:53:22,840 --> 00:53:26,440 Pain and spasticity are very hard to quantify in a research situation. 789 00:53:28,360 --> 00:53:30,960 Despite this, so far, the only available product 790 00:53:30,960 --> 00:53:34,200 is a treatment for pain caused by multiple sclerosis, 791 00:53:34,200 --> 00:53:37,200 and this is licensed only in Canada. 792 00:53:37,200 --> 00:53:40,440 But there's a possibility of treating many more ailments 793 00:53:40,440 --> 00:53:44,160 thanks to an unexpected property of the plant. 794 00:53:44,160 --> 00:53:45,760 If you look in the microscope, 795 00:53:45,760 --> 00:53:49,400 you can see some glistening golfball-like structures. 796 00:53:56,320 --> 00:53:58,880 And those are the glandular trichomes 797 00:53:58,880 --> 00:54:01,120 in the inflorescence of the plant 798 00:54:01,120 --> 00:54:04,440 which contain the chemicals we're interested in for making a medicine. 799 00:54:04,440 --> 00:54:05,880 It's not just THC. 800 00:54:05,880 --> 00:54:11,400 These trichomes contain CBD, another valuable chemical. 801 00:54:11,400 --> 00:54:15,640 There's a lot of CBD in that particular one as well, cannabidiol, another cannabinoid, 802 00:54:15,640 --> 00:54:19,520 a non-psychoactive cannabinoid, an important component to the medicine. 803 00:54:19,520 --> 00:54:23,760 So, from your point of view, in terms of developing medications, 804 00:54:23,760 --> 00:54:25,800 cannabidiol, CBD, what role does that have? 805 00:54:25,800 --> 00:54:29,240 We hope it's gonna... We're fascinated by this stuff, 806 00:54:29,240 --> 00:54:34,520 which has tremendous potential as an anti-inflammatory but also as an anti-psychotic. 807 00:54:34,520 --> 00:54:38,960 So you're telling me CBD could be a treatment for psychosis? 808 00:54:38,960 --> 00:54:40,440 Yes, isn't that ironic? 809 00:54:40,440 --> 00:54:44,440 With all the tremendous publicity around the link between cannabis smoking 810 00:54:44,440 --> 00:54:47,440 and the potential of increasing the risk of psychosis, 811 00:54:47,440 --> 00:54:51,480 here we have a component of the plant which itself is anti-psychotic. 812 00:54:51,480 --> 00:54:54,800 And we're saying... Within the same plant, you have a chemical 813 00:54:54,800 --> 00:54:56,400 which has an opposite effect 814 00:54:56,400 --> 00:54:59,080 and which therefore be protective to some extent? 815 00:54:59,080 --> 00:55:00,720 I think it's a level of concern 816 00:55:00,720 --> 00:55:03,440 that some of the recreational cannabis that's out there 817 00:55:03,440 --> 00:55:07,720 contains no CBD at all and that is a modern phenomenon. 818 00:55:07,720 --> 00:55:11,840 Previously, it was much more usual for people to be smoking cannabis 819 00:55:11,840 --> 00:55:14,320 some CBD in it at least. 820 00:55:14,320 --> 00:55:20,120 As recreational cannabis plants are grown for higher THC content, 821 00:55:20,120 --> 00:55:23,360 so their CBD content falls, 822 00:55:23,360 --> 00:55:27,520 simply because the plant isn't able to produce high levels of both. 823 00:55:27,520 --> 00:55:31,000 So your trick, as a developer of medication, 824 00:55:31,000 --> 00:55:34,920 is, I suppose, to change the relative balance of THC and CBD. 825 00:55:34,920 --> 00:55:40,120 Exactly so... Getting that proportion right for different conditions is going to be key. 826 00:55:40,120 --> 00:55:44,600 We think for pain and spasticity, a roughly equal balance of THC 827 00:55:44,600 --> 00:55:47,840 and CBD is good, because each has their own type of pharmacology, 828 00:55:47,840 --> 00:55:52,320 quite separate mechanisms of action, and they interact together in a helpful way. 829 00:55:52,320 --> 00:55:54,840 Probably along with other plant constituents too. 830 00:55:54,840 --> 00:55:58,800 But for other conditions like inflammation or psychosis, 831 00:55:58,800 --> 00:56:02,080 you wouldn't want, probably, any THC at all. 832 00:56:02,080 --> 00:56:04,360 You'd want some of the other plant components, 833 00:56:04,360 --> 00:56:08,240 but you'd want the CBD mainly, alongside those other components. 834 00:56:11,480 --> 00:56:15,760 For a plant that's been known and used medicinally for almost 3,000 years, 835 00:56:15,760 --> 00:56:20,720 it's surprising that new chemicals and uses are still being discovered. 836 00:56:20,720 --> 00:56:24,400 What I find even more surprising is that the medicinal use of cannabis 837 00:56:24,400 --> 00:56:27,640 is so far from being widely accepted. 838 00:56:32,360 --> 00:56:38,520 It seems to me that across the world, our relationship with cannabis remains confused. 839 00:56:38,520 --> 00:56:40,760 And not without reason. 840 00:56:40,760 --> 00:56:44,200 For many people, it brings them a great deal of pleasure. 841 00:56:46,040 --> 00:56:49,600 Unless you've actually tried it, you can't say how good it feels. 842 00:56:49,600 --> 00:56:52,840 All I know is that I feel absolutely fantastic. 843 00:56:52,840 --> 00:56:56,440 But all drug use comes with a price. 844 00:56:58,360 --> 00:57:00,960 It's like the old record says - you reap what you sow. 845 00:57:00,960 --> 00:57:03,040 And it's so true. 846 00:57:03,040 --> 00:57:09,320 Because I'm reaping what I sowed, and I regret it, I've just wasted my life. 847 00:57:09,320 --> 00:57:15,040 I've just let life pass me by because I've been sat in the chair just smoking cannabis. 848 00:57:15,040 --> 00:57:19,440 From what I've seen, unlike heroin and crack cocaine, the drugs that I deal with 849 00:57:19,440 --> 00:57:24,360 as a psychologist, cannabis is just not in the same league. 850 00:57:24,360 --> 00:57:28,200 It can't kill you, and it's very unlikely to ruin your life. 851 00:57:28,200 --> 00:57:30,840 But that's not to say it's entirely safe. 852 00:57:30,840 --> 00:57:36,720 Actually, I'm quite impressed with how much evidence has been gathered about the dangers. 853 00:57:36,720 --> 00:57:40,160 It seems to me that cannabis has no place in the developing brain. 854 00:57:40,160 --> 00:57:44,200 And although the numbers of people likely to be affected is tiny, 855 00:57:44,200 --> 00:57:46,200 there does appear to be a link 856 00:57:46,200 --> 00:57:50,040 between early use of cannabis and mental health problems. 857 00:57:50,040 --> 00:57:53,400 For our family, it's been absolutely devastating. 858 00:57:53,400 --> 00:57:57,000 Paul is still suffering the effects, still hears the voices. 859 00:57:57,000 --> 00:57:59,880 And possibly always will do. 860 00:57:59,880 --> 00:58:03,760 Yet these extreme effects are rare. 861 00:58:03,760 --> 00:58:10,200 In the end, it's my impression that the most significant damage caused by cannabis is subtle. 862 00:58:10,200 --> 00:58:11,880 It's not at the extremes, 863 00:58:11,880 --> 00:58:16,560 it's the thousands of regular smokers whose lives are held back. 864 00:58:16,560 --> 00:58:18,160 It's the apathy. 865 00:58:18,160 --> 00:58:21,960 It's the sitting around, smoking, not getting things done. 866 00:58:21,960 --> 00:58:26,360 The valuable, precious opportunities of life are lost. 867 00:58:32,680 --> 00:58:37,640 Subtitles by Red Bee Media Ltd