A lot of my patients "self-medicate" their psychiatric symptoms with assorted illegal substances. Marijuana is far and away the most popular choice. Because it comes from a plant, people generally are a lot more defensive about their cannabis usage than their use of meth or coke. Like Dan Sickles, who told us "Pot's harmless, man. I mean, I've been smoking it since I was six, and look at me, I'm fine."