What are the causes of drug abuse and alcoholism?

I'm assuming you mean, "What are the affects of Marijuana." Marijuana enters your blood stream through the lungs and causes your brain to make dopamine, the chemical it makes while you sleep to have dreams. This is a much more mild effect, and leads to extreme relaxation. It has also been known to cause paranoia, which may, or may not be, a normal side effect. There are no long term side-effects from marijuana, and overdosing is impossible. Marijuana may not be for some! If you experience bad reactions toward marijuana, you should quit.

Marijuana has also been known to be quite good for the body, especially in cases of disease such as, but not limited to, Cancer, MS, and AIDS. You see, Patients such as these may undergo chemotherapy, and marijuana has been known to help with the pain. I hope this gave you a more clear view on Marijuana.