It would be easy to assume that addictions of apparent biological origin were genetic but in many cases they are genetic only in relation to environmental susceptibility. Continual stimulous can have different results in different people. Society responds in like manner, blaming the addict, reaffirming the self-hatred. Perhaps then, we need to classify the hypersensitive as genetically predisposed. But if we do that, then we also have to classify the hyperinsensitive as genetically predisposed as well.
Stimulus is logical.
It has a cause and a result. If a child is provoked physically, psychologically or emotionally in a negative manner, there is going to be a reaction. Conformity, sociopathic or addictive, the diseased trifecta in our toxic society. Addiction is an escape. Chemical addictions that are a combo of psychological and biological are the most difficult to defeat.