I know that sounds really extreme, but if you just look at the history, you will find Harry Anslinger [first U.S. commissioner of the Bureau of Narcotics] going on about satanic swing and how reefer will make black people think they're as good as white people - which to him, obviously, was a very horrible outcome. This is the basis of our drug laws.

Marijuana is not not harmful, but is the least harmful psychoactive substance that we have, with the possible exception of caffeine.

I think our drug laws need to be made scientifically, as best as possible, recognizing that values will always be part of that.

Addiction is when you fall in love with a drug instead of a child or a lover and the learning that takes part in that part of the brain is designed by evolution to get us to persist despite negative consequences to do what we need to do - because I don't know anybody who could survive a relationship or parenting if not for the ability to persist despite negative consequences. The problem is when that gets misdirected to a drug and then you can find yourself in some very negative and potentially deadly situations.

A lot of addiction actually ends by age 30 - something like 50 percent of all addictions with the exception of tobacco - and I think a lot of what's going on there is that the self-control areas of the brain are finally developed enough to be able to stop yourself from relapsing or just continuing. There is a maturational aspect to it as well.

There is a safe, nontoxic drug called naloxone that can instantly reverse opioid overdose and prevent most of these deaths. But the drug war interferes with saving overdose victims in two ways: first, because witnesses to overdose fear prosecution, they often don't call for help until it's too late. Second, because the drug war supports the belief that making naloxone available over-the-counter or with opioid prescriptions would encourage drug use, the antidote is available only through harm reduction programs like needle exchanges or in some state programs aimed at drug users.

There's traditionally been two different ways of seeing addiction. Either it's a sin and you're a horrible bad person and you are just choosing to be hedonist or it's a chronic progressive disease. And while I certainly believe addiction is a medical problem that should be dealt with by the health system, the way we've conceptualized addiction as a disease is not actually accurate, and it has unfortunately become stigmatizing and it's also created a lot of hopelessness in a lot of people.