Conversation so far:
What's interesting about Charlie Parker that you read?
Charlie Parker was riddled with mental health problems and heroin addiction. Heroin use was prevalent in the jazz scene, and users could normally acquire it with little difficulty.
Did Charlie Parker die from mental health problems and heroin addiction?
The official causes of death were lobar pneumonia and a bleeding ulcer, but Charlie Parker also had an advanced case of cirrhosis and had suffered a heart attack.

Question: when did he start using heroin?
Self-contained rewrite: When did Charlie Parker start using heroin?