Well, there is a factor at play that most people don't understand. There is a tendency in people who are recovering from severe depression to die of suicide when they are on the upswing, recovering. When a therapist (or pdoc) is treating depression, they are aware that as the patient begins to get somewhat better, but not completely, the risk of suicide increases. This is something they should be watching for. One very likely explanation for this phenomenon is because a person in severe depression may feel suicidal, but be too depressed to act on it. As she or he begins to feel better, they may start feeling good enough to get the motivation together and act on the suicidal impulses. Because they are still in depression- just less severe, and a little less debilitated by it- this is sometimes where they will decide to end their life.

NO drug can "cause" someone to intentionally take their own life. People need to be a LOT more careful in assuming the causes of something, because there are other factors at play in many cases- such as this one.

I'm a psych major and I learned this in school, from a psychologist, if you're wondering whether this is true or whether it's my own speculation just spouting off.

Angela