I have a couple of comments. If you look at the general population, it's estimated that 10% of people who use methamphetamine will develop a substance use disorder immediately, just with one use. Typically, it's 10% within a lifetime with most substances, but the reinforcing effects of the methamphetamine are very, very strong. If you look at dopamine release in the brain with sex, it would be 10 times that with regards to what people get from methamphetamine, so it's 10 times orgasm and very reinforcing.
I'm not suggesting that this is what's going on, but it's analogous to that when you look at how intense the release of dopamine is in the brain with exposure. We also have to look at the risk factors. My colleague is absolutely right, because some of these might be genetic, some of these are epigenetic, adverse childhood experiences, trauma in childhood, exposure to the substance and then the pattern of exposure as well.
There are other people who get exposed to methamphetamine who I've had as patients who hate it. They've tried it once or twice, and they dislike it; they don't like the way it makes them feel. There are definitely individual characteristics that speak to some people and repel others.