While I sympathize with your friend's troubles, marijuana has had a completely different effect for me. Before I started smoking, I was extremely anal-retentive and difficult to get along with. I was repeatedly told by my closest friends that I could quite an ass-hole. In addition, I was depressed for most of my high school and early college career. I like to think I am a much different person after a year of smoking. I am a lot more laid back, am much easier to get along with, am no longer depressed, and have made quite a few new friends along the way. So.... you're right, mairjuana -can- change people, but -how- it will do so is, in my opinion, more of a function of the person than the pot.