WEBVTT 00:00:01.060 --> 00:00:04.075 This is a tuberculosis ward, 00:00:04.100 --> 00:00:07.916 and at the time this picture was taken in the late 1800s, 00:00:07.939 --> 00:00:10.556 one in seven of all people 00:00:10.580 --> 00:00:12.340 died from tuberculosis. 00:00:12.780 --> 00:00:15.540 We had no idea what was causing this disease. 00:00:16.140 --> 00:00:18.196 The hypothesis was actually 00:00:18.220 --> 00:00:21.476 it was your constitution that made you susceptible. 00:00:21.500 --> 00:00:24.236 And it was a highly romanticized disease. 00:00:24.260 --> 00:00:27.076 It was also called consumption, 00:00:27.100 --> 00:00:30.236 and it was the disorder of poets 00:00:30.260 --> 00:00:32.996 and artists and intellectuals. 00:00:33.020 --> 00:00:36.756 And some people actually thought it gave you heightened sensitivity 00:00:36.780 --> 00:00:38.980 and conferred creative genius. NOTE Paragraph 00:00:40.700 --> 00:00:42.836 By the 1950s, 00:00:42.860 --> 00:00:45.436 we instead knew that tuberculosis was caused 00:00:45.460 --> 00:00:48.836 by a highly contagious bacterial infection, 00:00:48.860 --> 00:00:51.036 which is slightly less romantic, 00:00:51.060 --> 00:00:53.316 but that had the upside 00:00:53.340 --> 00:00:56.676 of us being able to maybe develop drugs to treat it. 00:00:56.700 --> 00:00:59.716 So doctors had discovered a new drug, iproniazid, 00:00:59.740 --> 00:01:03.116 that they were optimistic might cure tuberculosis, 00:01:03.140 --> 00:01:04.916 and they gave it to patients, 00:01:04.940 --> 00:01:06.716 and patients were elated. 00:01:06.740 --> 00:01:10.236 They were more social, more energetic. 00:01:10.260 --> 00:01:14.860 One medical report actually says they were "dancing in the halls." 00:01:15.500 --> 00:01:17.116 And unfortunately, 00:01:17.140 --> 00:01:19.860 this was not necessarily because they were getting better. 00:01:20.420 --> 00:01:22.620 A lot of them were still dying. 00:01:23.660 --> 00:01:30.260 Another medical report describes them as being "inappropriately happy." 00:01:31.220 --> 00:01:34.820 And that is how the first antidepressant was discovered. NOTE Paragraph 00:01:35.980 --> 00:01:40.036 So accidental discovery is not uncommon in science, 00:01:40.060 --> 00:01:43.196 but it requires more than just a happy accident. 00:01:43.220 --> 00:01:46.660 You have to be able to recognize it for discovery to occur. NOTE Paragraph 00:01:47.500 --> 00:01:50.236 As a neuroscientist, I'm going to talk to you a little bit 00:01:50.260 --> 00:01:51.676 about my firsthand experience 00:01:51.700 --> 00:01:54.916 with whatever you want to call the opposite of dumb luck -- 00:01:54.940 --> 00:01:56.556 let's call it smart luck. 00:01:56.580 --> 00:01:59.300 But first, a bit more background. NOTE Paragraph 00:02:00.460 --> 00:02:03.116 Thankfully, since the 1950s, 00:02:03.140 --> 00:02:07.116 we've developed some other drugs and we can actually now cure tuberculosis. 00:02:07.140 --> 00:02:10.795 And at least in the United States, though not necessarily in other countries, 00:02:10.820 --> 00:02:12.316 we have closed our sanitoriums 00:02:12.340 --> 00:02:16.020 and probably most of you are not too worried about TB. 00:02:16.900 --> 00:02:19.556 But a lot of what was true in the early 1900s 00:02:19.580 --> 00:02:21.436 about infectious disease, 00:02:21.460 --> 00:02:24.100 we can say now about psychiatric disorders. NOTE Paragraph 00:02:24.820 --> 00:02:27.836 We are in the middle of an epidemic of mood disorders 00:02:27.860 --> 00:02:31.620 like depression and post-traumatic stress disorder, or PTSD. 00:02:32.300 --> 00:02:36.156 One in four of all adults in the United States 00:02:36.180 --> 00:02:37.660 suffers from mental illness, 00:02:38.180 --> 00:02:41.316 which means that if you haven't experienced it personally 00:02:41.340 --> 00:02:43.636 or someone in your family hasn't, 00:02:43.660 --> 00:02:46.916 it's still very likely that someone you know has, 00:02:46.940 --> 00:02:48.580 though they may not talk about it. 00:02:50.220 --> 00:02:53.516 Depression has actually now surpassed 00:02:53.540 --> 00:02:58.396 HIV/AIDS, malaria, diabetes and war 00:02:58.420 --> 00:03:01.676 as the leading cause of disability worldwide. 00:03:01.700 --> 00:03:05.316 And also, like tuberculosis in the 1950s, 00:03:05.340 --> 00:03:07.396 we don't know what causes it. 00:03:07.420 --> 00:03:09.356 Once it's developed, it's chronic, 00:03:09.380 --> 00:03:10.876 lasts a lifetime, 00:03:10.900 --> 00:03:13.220 and there are no known cures. NOTE Paragraph 00:03:14.660 --> 00:03:16.876 The second antidepressant we discovered, 00:03:16.900 --> 00:03:19.356 also by accident, in the 1950s, 00:03:19.380 --> 00:03:22.580 from an antihistamine that was making people manic, 00:03:23.860 --> 00:03:25.060 imipramine. 00:03:26.220 --> 00:03:29.876 And in both the case of the tuberculosis ward and the antihistamine, 00:03:29.900 --> 00:03:31.596 someone had to be able to recognize 00:03:31.620 --> 00:03:34.036 that a drug that was designed to do one thing -- 00:03:34.060 --> 00:03:36.636 treat tuberculosis or suppress allergies -- 00:03:36.660 --> 00:03:39.396 could be used to do something very different -- 00:03:39.420 --> 00:03:40.620 treat depression. 00:03:41.380 --> 00:03:44.396 And this sort of repurposing is actually quite challenging. 00:03:44.420 --> 00:03:48.356 When doctors first saw this mood-enhancing effect of iproniazid, 00:03:48.380 --> 00:03:50.836 they didn't really recognize what they saw. 00:03:50.860 --> 00:03:52.716 They were so used to thinking about it 00:03:52.740 --> 00:03:55.516 from the framework of being a tuberculosis drug 00:03:55.540 --> 00:03:57.596 that they actually just listed it 00:03:57.620 --> 00:04:00.396 as a side effect, an adverse side effect. NOTE Paragraph 00:04:00.420 --> 00:04:01.571 As you can see here, 00:04:01.596 --> 00:04:05.620 a lot of these patients in 1954 are experiencing severe euphoria. 00:04:06.900 --> 00:04:10.516 And they were worried that this might somehow interfere 00:04:10.540 --> 00:04:13.396 with their recovering from tuberculosis. 00:04:13.420 --> 00:04:19.676 So they recommended that iproniazid only be used in cases of extreme TB 00:04:19.700 --> 00:04:23.380 and in patients that were highly emotionally stable, 00:04:24.220 --> 00:04:28.116 which is of course the exact opposite of how we use it as an antidepressant. 00:04:28.140 --> 00:04:32.596 They were so used to looking at it from the perspective of this one disease, 00:04:32.620 --> 00:04:36.540 they could not see the larger implications for another disease. NOTE Paragraph 00:04:37.380 --> 00:04:40.076 And to be fair, it's not entirely their fault. 00:04:40.100 --> 00:04:42.876 Functional fixedness is a bias that affects all of us. 00:04:42.900 --> 00:04:46.356 It's a tendency to only be able to think of an object 00:04:46.380 --> 00:04:48.980 in terms of its traditional use or function. 00:04:49.740 --> 00:04:51.636 And mental set is another thing. Right? 00:04:51.660 --> 00:04:53.676 That's sort of this preconceived framework 00:04:53.700 --> 00:04:55.476 with which we approach problems. 00:04:55.500 --> 00:04:58.756 And that actually makes repurposing pretty hard for all of us, 00:04:58.780 --> 00:05:02.316 which is, I guess, why they gave a TV show to the guy who was, 00:05:02.340 --> 00:05:04.140 like, really great at repurposing. NOTE Paragraph 00:05:04.660 --> 00:05:06.540 (Laughter) NOTE Paragraph 00:05:07.180 --> 00:05:11.516 So the effects in both the case of iproniazid and imipramine, 00:05:11.540 --> 00:05:12.916 they were so strong -- 00:05:12.940 --> 00:05:15.156 there was mania, or people dancing in the halls. 00:05:15.180 --> 00:05:18.316 It's actually not that surprising they were caught. 00:05:18.340 --> 00:05:21.820 But it does make you wonder what else we've missed. 00:05:23.020 --> 00:05:25.196 So iproniazid and imipramine, 00:05:25.220 --> 00:05:27.636 they're more than just a case study in repurposing. 00:05:27.660 --> 00:05:30.636 They have two other things in common that are really important. 00:05:30.660 --> 00:05:33.156 One, they have terrible side effects. 00:05:33.180 --> 00:05:35.796 That includes liver toxicity, 00:05:35.820 --> 00:05:38.796 weight gain of over 50 pounds, 00:05:38.820 --> 00:05:40.596 suicidality. 00:05:40.620 --> 00:05:44.796 And two, they both increase levels of serotonin, 00:05:44.820 --> 00:05:47.156 which is a chemical signal in the brain, 00:05:47.180 --> 00:05:48.380 or a neurotransmitter. 00:05:49.380 --> 00:05:51.876 And those two things together, right, one or the two, 00:05:51.900 --> 00:05:53.516 may not have been that important, 00:05:53.540 --> 00:05:57.276 but the two together meant that we had to develop safer drugs, 00:05:57.300 --> 00:06:00.820 and that serotonin seemed like a pretty good place to start. NOTE Paragraph 00:06:01.660 --> 00:06:05.556 So we developed drugs to more specifically focus on serotonin, 00:06:05.580 --> 00:06:09.236 the selective serotonin reuptake inhibitors, so the SSRIs, 00:06:09.260 --> 00:06:11.996 the most famous of which is Prozac. 00:06:12.020 --> 00:06:13.996 And that was 30 years ago, 00:06:14.020 --> 00:06:17.220 and since then we have mostly just worked on optimizing those drugs. 00:06:17.740 --> 00:06:20.956 And the SSRIs, they are better than the drugs that came before them, 00:06:20.980 --> 00:06:23.076 but they still have a lot of side effects, 00:06:23.100 --> 00:06:25.996 including weight gain, insomnia, 00:06:26.020 --> 00:06:27.220 suicidality -- 00:06:28.100 --> 00:06:30.436 and they take a really long time to work, 00:06:30.460 --> 00:06:32.996 something like four to six weeks in a lot of patients. 00:06:33.020 --> 00:06:35.196 And that's in the patients where they do work. 00:06:35.220 --> 00:06:38.076 There are a lot of patients where these drugs don't work. NOTE Paragraph 00:06:38.100 --> 00:06:41.476 And that means now, in 2016, 00:06:41.500 --> 00:06:45.316 we still have no cures for any mood disorders, 00:06:45.340 --> 00:06:47.396 just drugs that suppress symptoms, 00:06:47.420 --> 00:06:51.476 which is kind of the difference between taking a painkiller for an infection 00:06:51.500 --> 00:06:52.916 versus an antibiotic. 00:06:52.940 --> 00:06:54.796 A painkiller will make you feel better, 00:06:54.820 --> 00:06:57.900 but is not going to do anything to treat that underlying disease. 00:06:58.700 --> 00:07:01.036 And it was this flexibility in our thinking 00:07:01.060 --> 00:07:03.996 that let us recognize that iproniazid and imipramine 00:07:04.020 --> 00:07:06.116 could be repurposed in this way, 00:07:06.140 --> 00:07:08.116 which led us to the serotonin hypothesis, 00:07:08.140 --> 00:07:11.140 which we then, ironically, fixated on. 00:07:11.980 --> 00:07:14.516 This is brain signaling, serotonin, 00:07:14.540 --> 00:07:15.796 from an SSRI commercial. 00:07:15.820 --> 00:07:18.180 In case you're not clear, this is a dramatization. 00:07:18.660 --> 00:07:22.716 And in science, we try and remove our bias, right, 00:07:22.740 --> 00:07:25.116 by running double-blinded experiments 00:07:25.140 --> 00:07:28.836 or being statistically agnostic as to what our results will be. 00:07:28.860 --> 00:07:33.156 But bias creeps in more insidiously in what we choose to study 00:07:33.180 --> 00:07:34.900 and how we choose to study it. NOTE Paragraph 00:07:36.260 --> 00:07:39.836 So we've focused on serotonin now for the past 30 years, 00:07:39.860 --> 00:07:42.100 often to the exclusion of other things. 00:07:42.860 --> 00:07:44.220 We still have no cures, 00:07:45.180 --> 00:07:48.596 and what if serotonin isn't all there is to depression? 00:07:48.620 --> 00:07:50.676 What if it's not even the key part of it? 00:07:50.700 --> 00:07:52.876 That means no matter how much time 00:07:52.900 --> 00:07:55.636 or money or effort we put into it, 00:07:55.660 --> 00:07:57.580 it will never lead to a cure. NOTE Paragraph 00:07:58.500 --> 00:08:01.076 In the past few years, doctors have discovered 00:08:01.100 --> 00:08:06.020 probably what is the first truly new antidepressant since the SSRIs, 00:08:06.540 --> 00:08:07.836 Calypsol, 00:08:07.860 --> 00:08:11.316 and this drug works very quickly, within a few hours or a day, 00:08:11.340 --> 00:08:13.236 and it doesn't work on serotonin. 00:08:13.260 --> 00:08:15.940 It works on glutamate, which is another neurotransmitter. 00:08:16.380 --> 00:08:17.876 And it's also repurposed. 00:08:17.900 --> 00:08:20.980 It was traditionally used as anesthesia in surgery. 00:08:21.540 --> 00:08:23.196 But unlike those other drugs, 00:08:23.220 --> 00:08:25.036 which were recognized pretty quickly, 00:08:25.060 --> 00:08:26.756 it took us 20 years 00:08:26.780 --> 00:08:29.436 to realize that Calypsol was an antidepressant, 00:08:29.460 --> 00:08:32.316 despite the fact that it's actually a better antidepressant, 00:08:32.340 --> 00:08:33.956 probably, than those other drugs. 00:08:33.980 --> 00:08:38.076 It's actually probably because of the fact that it's a better antidepressant 00:08:38.100 --> 00:08:39.995 that it was harder for us to recognize. 00:08:40.019 --> 00:08:42.100 There was no mania to signal its effects. NOTE Paragraph 00:08:42.580 --> 00:08:45.676 So in 2013, up at Columbia University, 00:08:45.700 --> 00:08:47.276 I was working with my colleague, 00:08:47.300 --> 00:08:49.276 Dr. Christine Ann Denny, 00:08:49.300 --> 00:08:53.100 and we were studying Calypsol as an antidepressant in mice. 00:08:53.660 --> 00:08:56.476 And Calypsol has, like, a really short half-life, 00:08:56.500 --> 00:08:59.556 which means it's out of your body within a few hours. 00:08:59.580 --> 00:09:00.996 And we were just piloting. 00:09:01.020 --> 00:09:03.276 So we would give an injection to mice, 00:09:03.300 --> 00:09:04.596 and then we'd wait a week, 00:09:04.620 --> 00:09:07.300 and then we'd run another experiment to save money. NOTE Paragraph 00:09:08.020 --> 00:09:10.156 And one of the experiments I was running, 00:09:10.180 --> 00:09:11.836 we would stress the mice, 00:09:11.860 --> 00:09:14.076 and we used that as a model of depression. 00:09:14.100 --> 00:09:17.436 And at first it kind of just looked like it didn't really work at all. 00:09:17.460 --> 00:09:18.980 So we could have stopped there. 00:09:19.540 --> 00:09:22.436 But I have run this model of depression for years, 00:09:22.460 --> 00:09:24.356 and the data just looked kind of weird. 00:09:24.380 --> 00:09:26.236 It didn't really look right to me. 00:09:26.260 --> 00:09:27.476 So I went back, 00:09:27.500 --> 00:09:28.996 and we reanalyzed it 00:09:29.020 --> 00:09:32.836 based on whether or not they had gotten that one injection of Calypsol 00:09:32.860 --> 00:09:34.060 a week beforehand. 00:09:34.940 --> 00:09:36.956 And it looked kind of like this. 00:09:36.980 --> 00:09:39.116 So if you look at the far left, 00:09:39.140 --> 00:09:41.636 if you put a mouse in a new space, 00:09:41.660 --> 00:09:43.916 this is the box, it's very exciting, 00:09:43.940 --> 00:09:46.076 a mouse will walk around and explore, 00:09:46.100 --> 00:09:50.396 and you can see that pink line is actually the measure of them walking. 00:09:50.420 --> 00:09:53.596 And we also give it another mouse in a pencil cup 00:09:53.620 --> 00:09:55.676 that it can decide to interact with. 00:09:55.700 --> 00:09:58.916 This is also a dramatization, in case that's not clear. 00:09:58.940 --> 00:10:02.636 And a normal mouse will explore. 00:10:02.660 --> 00:10:03.900 It will be social. 00:10:04.620 --> 00:10:05.996 Check out what's going on. 00:10:06.020 --> 00:10:08.916 If you stress a mouse in this depression model, 00:10:08.940 --> 00:10:10.220 which is the middle box, 00:10:11.100 --> 00:10:12.996 they aren't social, they don't explore. 00:10:13.020 --> 00:10:16.300 They mostly just kind of hide in that back corner, behind a cup. 00:10:17.020 --> 00:10:20.116 Yet the mice that had gotten that one injection of Calypsol, 00:10:20.140 --> 00:10:21.340 here on your right, 00:10:22.060 --> 00:10:24.020 they were exploring, they were social. 00:10:24.740 --> 00:10:27.220 They looked like they had never been stressed at all, 00:10:28.020 --> 00:10:29.220 which is impossible. NOTE Paragraph 00:10:30.260 --> 00:10:31.980 So we could have just stopped there, 00:10:32.780 --> 00:10:37.076 but Christine had also used Calypsol before as anesthesia, 00:10:37.100 --> 00:10:38.676 and a few years ago she had seen 00:10:38.700 --> 00:10:41.076 that it seemed to have some weird effects on cells 00:10:41.100 --> 00:10:42.316 and some other behavior 00:10:42.340 --> 00:10:45.356 that also seemed to last long after the drug, 00:10:45.380 --> 00:10:46.636 maybe a few weeks. 00:10:46.660 --> 00:10:47.916 So we were like, OK, 00:10:47.940 --> 00:10:50.116 maybe this is not completely impossible, 00:10:50.140 --> 00:10:51.636 but we were really skeptical. NOTE Paragraph 00:10:51.660 --> 00:10:54.196 So we did what you do in science when you're not sure, 00:10:54.220 --> 00:10:55.420 and we ran it again. 00:10:56.460 --> 00:10:59.476 And I remember being in the animal room, 00:10:59.500 --> 00:11:03.156 moving mice from box to box to test them, 00:11:03.180 --> 00:11:06.796 and Christine was actually sitting on the floor with the computer in her lap 00:11:06.820 --> 00:11:08.236 so the mice couldn't see her, 00:11:08.260 --> 00:11:10.516 and she was analyzing the data in real time. 00:11:10.540 --> 00:11:11.916 And I remember us yelling, 00:11:11.940 --> 00:11:15.236 which you're not supposed to do in an animal room where you're testing, 00:11:15.260 --> 00:11:16.836 because it had worked. 00:11:16.860 --> 00:11:21.236 It seemed like these mice were protected against stress, 00:11:21.260 --> 00:11:24.316 or they were inappropriately happy, however you want to call it. 00:11:24.340 --> 00:11:26.780 And we were really excited. NOTE Paragraph 00:11:27.820 --> 00:11:31.300 And then we were really skeptical, because it was too good to be true. 00:11:31.860 --> 00:11:33.060 So we ran it again. 00:11:33.740 --> 00:11:36.476 And then we ran it again in a PTSD model, 00:11:36.500 --> 00:11:38.916 and we ran it again in a physiological model, 00:11:38.940 --> 00:11:41.156 where all we did was give stress hormones. 00:11:41.180 --> 00:11:42.796 And we had our undergrads run it. 00:11:42.820 --> 00:11:46.940 And then we had our collaborators halfway across the world in France run it. 00:11:47.780 --> 00:11:50.996 And every time someone ran it, they confirmed the same thing. 00:11:51.020 --> 00:11:53.836 It seemed like this one injection of Calypsol 00:11:53.860 --> 00:11:56.620 was somehow protecting against stress for weeks. NOTE Paragraph 00:11:57.180 --> 00:11:59.036 And we only published this a year ago, 00:11:59.060 --> 00:12:03.140 but since then other labs have independently confirmed this effect. 00:12:03.940 --> 00:12:05.860 So we don't know what causes depression, 00:12:06.460 --> 00:12:10.156 but we do know that stress is the initial trigger 00:12:10.180 --> 00:12:12.516 in 80 percent of cases, 00:12:12.540 --> 00:12:14.756 and depression and PTSD are different diseases, 00:12:14.780 --> 00:12:16.796 but this is something they share in common. 00:12:16.820 --> 00:12:18.636 Right? It is traumatic stress 00:12:18.660 --> 00:12:21.556 like active combat or natural disasters 00:12:21.580 --> 00:12:24.036 or community violence or sexual assault 00:12:24.060 --> 00:12:26.340 that causes post-traumatic stress disorder, 00:12:26.980 --> 00:12:32.596 and not everyone that is exposed to stress develops a mood disorder. 00:12:32.620 --> 00:12:35.516 And this ability to experience stress and be resilient 00:12:35.540 --> 00:12:39.700 and bounce back and not develop depression or PTSD 00:12:40.500 --> 00:12:42.756 is known as stress resilience, 00:12:42.780 --> 00:12:44.636 and it varies between people. 00:12:44.660 --> 00:12:47.996 And we have always thought of it as just sort of this passive property. 00:12:48.020 --> 00:12:50.556 It's the absence of susceptibility factors 00:12:50.580 --> 00:12:52.660 and risk factors for these disorders. 00:12:53.620 --> 00:12:55.500 But what if it were active? 00:12:56.420 --> 00:12:57.916 Maybe we could enhance it, 00:12:57.940 --> 00:13:00.100 sort of akin to putting on armor. NOTE Paragraph 00:13:01.220 --> 00:13:05.820 We had accidentally discovered the first resilience-enhancing drug. 00:13:06.740 --> 00:13:09.516 And like I said, we only gave a tiny amount of the drug, 00:13:09.540 --> 00:13:11.116 and it lasted for weeks, 00:13:11.140 --> 00:13:14.356 and that's not like anything you see with antidepressants. NOTE Paragraph 00:13:14.380 --> 00:13:18.700 But it is actually kind of similar to what you see in immune vaccines. 00:13:19.180 --> 00:13:22.116 So in immune vaccines, you'll get your shots, 00:13:22.140 --> 00:13:25.516 and then weeks, months, years later, 00:13:25.540 --> 00:13:27.876 when you're actually exposed to bacteria, 00:13:27.900 --> 00:13:30.356 it's not the vaccine in your body that protects you. 00:13:30.380 --> 00:13:31.756 It's your own immune system 00:13:31.780 --> 00:13:35.916 that's developed resistance and resilience to this bacteria that fights it off, 00:13:35.940 --> 00:13:38.076 and you actually never get the infection, 00:13:38.100 --> 00:13:41.156 which is very different from, say, our treatments. Right? 00:13:41.180 --> 00:13:44.996 In that case, you get the infection, you're exposed to the bacteria, 00:13:45.020 --> 00:13:48.876 you're sick, and then you take, say, an antibiotic which cures it, 00:13:48.900 --> 00:13:52.140 and those drugs are actually working to kill the bacteria. 00:13:52.780 --> 00:13:55.276 Or similar to as I said before, with this palliative, 00:13:55.300 --> 00:13:58.156 you'll take something that will suppress the symptoms, 00:13:58.180 --> 00:14:00.876 but it won't treat the underlying infection, 00:14:00.900 --> 00:14:04.236 and you'll only feel better during the time in which you're taking it, 00:14:04.260 --> 00:14:06.196 which is why you have to keep taking it. 00:14:06.220 --> 00:14:08.916 And in depression and PTSD -- 00:14:08.940 --> 00:14:10.916 here we have your stress exposure -- 00:14:10.940 --> 00:14:13.556 we only have palliative care. 00:14:13.580 --> 00:14:16.076 Antidepressants only suppress symptoms, 00:14:16.100 --> 00:14:18.956 and that is why you basically have to keep taking them 00:14:18.980 --> 00:14:20.676 for the life of the disease, 00:14:20.700 --> 00:14:22.900 which is often the length of your own life. NOTE Paragraph 00:14:23.940 --> 00:14:28.156 So we're calling our resilience-enhancing drugs "paravaccines," 00:14:28.180 --> 00:14:29.716 which means vaccine-like, 00:14:29.740 --> 00:14:32.236 because it seems like they might have the potential 00:14:32.260 --> 00:14:34.076 to protect against stress 00:14:34.100 --> 00:14:37.516 and prevent mice from developing 00:14:37.540 --> 00:14:40.300 depression and post-traumatic stress disorder. 00:14:40.780 --> 00:14:44.220 Also, not all antidepressants are also paravaccines. 00:14:45.300 --> 00:14:46.916 We tried Prozac as well, 00:14:46.940 --> 00:14:48.300 and that had no effect. NOTE Paragraph 00:14:49.060 --> 00:14:52.076 So if this were to translate into humans, 00:14:52.100 --> 00:14:54.676 we might be able to protect people 00:14:54.700 --> 00:14:56.956 who are predictably at risk 00:14:56.980 --> 00:15:00.836 against stress-induced disorders like depression and PTSD. 00:15:00.860 --> 00:15:03.996 So that's first responders and firefighters, 00:15:04.020 --> 00:15:08.156 refugees, prisoners and prison guards, 00:15:08.180 --> 00:15:10.260 soldiers, you name it. NOTE Paragraph 00:15:11.220 --> 00:15:15.020 And to give you a sense of the scale of these diseases, 00:15:15.620 --> 00:15:18.676 in 2010, the global burden of disease 00:15:18.700 --> 00:15:22.540 was estimated at 2.5 trillion dollars, 00:15:23.060 --> 00:15:24.596 and since they are chronic, 00:15:24.620 --> 00:15:27.836 that cost is compounding and is therefore expected to rise 00:15:27.860 --> 00:15:31.100 up to six trillion dollars in just the next 15 years. NOTE Paragraph 00:15:32.460 --> 00:15:34.039 As I mentioned before, 00:15:34.064 --> 00:15:38.140 repurposing can be challenging because of our prior biases. 00:15:38.860 --> 00:15:40.380 Calypsol has another name, 00:15:41.100 --> 00:15:42.300 ketamine, 00:15:43.380 --> 00:15:44.940 which also goes by another name, 00:15:45.460 --> 00:15:46.876 Special K, 00:15:46.900 --> 00:15:49.300 which is a club drug and drug of abuse. 00:15:50.540 --> 00:15:53.636 It's still used across the world as an anesthetic. 00:15:53.660 --> 00:15:56.516 It's used in children. We use it on the battlefield. 00:15:56.540 --> 00:15:59.516 It's actually the drug of choice in a lot of developing nations, 00:15:59.540 --> 00:16:01.396 because it doesn't affect breathing. 00:16:01.420 --> 00:16:06.100 It is on the World Health Organization list of most essential medicines. NOTE Paragraph 00:16:06.580 --> 00:16:10.140 If we had discovered ketamine as a paravaccine first, 00:16:10.820 --> 00:16:13.676 it'd be pretty easy for us to develop it, 00:16:13.700 --> 00:16:17.556 but as is, we have to compete with our functional fixedness 00:16:17.580 --> 00:16:20.380 and mental set that kind of interfere. 00:16:21.700 --> 00:16:25.556 Fortunately, it's not the only compound we have discovered 00:16:25.580 --> 00:16:29.020 that has these prophylactic, paravaccine qualities, 00:16:29.700 --> 00:16:31.900 but all of the other drugs we've discovered, 00:16:32.780 --> 00:16:34.956 or compounds if you will, they're totally new, 00:16:34.980 --> 00:16:38.596 they have to go through the entire FDA approval process -- 00:16:38.620 --> 00:16:42.196 if they make it before they can ever be used in humans. 00:16:42.220 --> 00:16:43.876 And that will be years. 00:16:43.900 --> 00:16:46.156 So if we wanted something sooner, 00:16:46.180 --> 00:16:48.556 ketamine is already FDA-approved. 00:16:48.580 --> 00:16:51.276 It's generic, it's available. 00:16:51.300 --> 00:16:55.460 We could develop it for a fraction of the price and a fraction of the time. NOTE Paragraph 00:16:56.380 --> 00:17:00.756 But actually, beyond functional fixedness and mental set, 00:17:00.780 --> 00:17:04.356 there's a real other challenge to repurposing drugs, 00:17:04.380 --> 00:17:05.579 which is policy. 00:17:06.179 --> 00:17:08.395 There are no incentives in place 00:17:08.419 --> 00:17:12.155 once a drug is generic and off patent and no longer exclusive 00:17:12.179 --> 00:17:14.516 to encourage pharma companies to develop them, 00:17:14.540 --> 00:17:15.969 because they don't make money. 00:17:16.380 --> 00:17:19.500 And that's not true for just ketamine. That is true for all drugs. 00:17:20.579 --> 00:17:26.236 Regardless, the idea itself is completely novel in psychiatry, 00:17:26.260 --> 00:17:30.156 to use drugs to prevent mental illness 00:17:30.180 --> 00:17:31.540 as opposed to just treat it. NOTE Paragraph 00:17:32.740 --> 00:17:37.796 It is possible that 20, 50, 100 years from now, 00:17:37.820 --> 00:17:41.916 we will look back now at depression and PTSD 00:17:41.940 --> 00:17:45.156 the way we look back at tuberculosis sanitoriums 00:17:45.180 --> 00:17:46.380 as a thing of the past. 00:17:47.180 --> 00:17:52.420 This could be the beginning of the end of the mental health epidemic. NOTE Paragraph 00:17:53.380 --> 00:17:56.580 But as a great scientist once said, 00:17:57.900 --> 00:18:00.156 "Only a fool is sure of anything. 00:18:00.180 --> 00:18:02.220 A wise man keeps on guessing." NOTE Paragraph 00:18:04.044 --> 00:18:05.284 Thank you, guys. NOTE Paragraph 00:18:05.780 --> 00:18:09.846 (Applause)