What is considered "Suicide"?

I would agree with your definition. I wouldn't say a drug overdose is considered suicide IF it was accidental. For Example, if someone deliberately put too much heroin in a needle vs if someone just took too much for the last time. I don't consider accidents suicide. Or say if you did overdose, you knew you were overdosing, and you didn't call an 911, than I would think that inaction would be considered as suicide.