Not all drugs are created equal. So which substances are the most dangerous? >> Tobacco, but not necessarily the nicotine. >> Yeah. >> Tell us why. Why is it the most dangerous? >> Because it's the other components in smoked tobacco that will kill you. >> It kills a large number of people [CROSSTALK] >> And and reduces quality of life, dramatically for some people, less dramatically for others. But it's not just lung cancer. It's hard to disease, and- >> COPD. >> What? >> COPD. >> COPD, yeah. So that gets back to the question of harm reduction, is something like are e-cigarettes harm reduction? We do have ways to treat tobacco use without and without making people nicotine-free. There's gum. There's patches. There's e-cigarettes. If we cannot ascribe harm to the nicotine addiction itself, or the nicotine dependence itself, we have ways to reverse the harms from tobacco. >> Does anybody have other substances? >> I think from a public health standpoint, I completely agree with you. But I think from the individual standpoint, it's whatever substance is become an issue for you, right? Whatever substance you've lost control over. So I have a patient who PCP has ripped his life apart, and we don't think about that in the traditional way that we've talked about opioids and alcohol here in some settings, and certainly. But I think from the individual standpoint, if you as a provider in a treatment setting, if you have a framework to approach a patient in terms of talking to them about risks and how substances have impacted their life, and understanding which substance has become problematic for that patient, coming up with treatment plans to help them mitigate those harms is really what you need to focus on. So as far as I'm concerned, it may be cannabis for individual patients where they've really lost control, and maybe caffeine for others, right? >> So one thing that comes to my mind about I don't disagree that nicotine has is very harmful. And it absolutely harms the individual who smokes, and there's no doubt that there's second-hand smoke issues. But there are other substances that do seem to cause more interpersonal violence, other impacts to society, namely alcohol, that is often associated with traffic accidents, missed days at work, family violence, child abuse, etc., etc. So it can be very difficult. So it kind of depends on, I think getting at your point, what are we taught, danger for what, right? >> David Nutt had a paper in The Lancet where looked at UK and in the relative risks and costs of different substances. And I believe it was nicotine first, alcohol second, and then way, way down the line, opiates and methamphetamine was very high on social costs in the various different ways. And it looked at all sorts of different substances and their relative cost to society and to individuals, and ranked them in that way. It's a good paper to look at for that question. But I think it's nicotine first, alcohol second, opioids, and methamphetamine, yeah. >> As an epidemiologist, I have to look at groups of people, I can't help individuals. >> If there are ten of you, maybe I can do something. >> [LAUGH] >> Just also gets me thinking, sort of nicotine might take a little longer period of use before the- >> Harms come. >> Harms are really realized. Whereas opioids might have risk first time in overdose. And then, there's also the aspect of route of administration. Same substance used in different ways can have different risks associated with it. Sort of the onset of it becoming a disorder, or the risk and secondary, sort of as we said, if the person has injected or used another needle. Someone else's needle, as sort of the route of administration, can also, I think, predict the harm associated with it.