Experts in the field of substance abuse were asked about the relative addictiveness of various drugs. at the top of the list, as most addictive, was

I believe it's amphetamines. They release chemicals called catecholamines, particularly dopamine. Tolerance to these build very fast making them highly addictive.

Not sure exactly what kind of answer you are looking for so i hope this able to be a effective listener and also being  a good conversationalist. and most of all just being there when someone needs you.i hope this .