Genetics, but also environmental. Children of addicts, IIRC, are close to an order of magnitude more likely to become addicts themselves (as compared to childre

Genetics, but also environmental. Children of addicts, IIRC, are close to an order of magnitude more likely to become addicts themselves (as compared to children of non-addicts)[0]. [0] Sorry, I can't cite that source ATM, just something I recall from foster parent training.