Seneca,
When the strength of wine has become too great and has gained control over the mind, every lurking evil comes forth from its hiding-place. Drunkenness does not create vice, it merely brings it into view…
It has long been my contention that intoxication of this sort does not bring about new evils. It simply rearranges priorities. As you note, the lustful man does not hide his vice, nor does the cruel man but become more cruel. Alcohol and the like seem not to create new evils, but only bring them to the surface.
There are, perhaps, other more rare vices which do seem to change the quality of the person, if not with a single use but through prolonged exposure. The heartily addicted sometime seem this way.
It is still due to ignorance that mean do evil:
[T]hat what men call pleasures are punishments as soon as they have exceeded due bounds
All are deprived of truth against their will. It is through a misunderstanding good and evil that folks seek escape or (incorrect) therapy for their passions. You will sometimes see it claimed that addiction is moral problem, not a criminal one.
I generally agree with this sentiment, but would take a Stoic turn. It’s not that person needs to be saved to change their behavior, but that they must instead learn to distinguish between what’s good and evil, and what’s up to us and what’s not. In short, they must learn to diaresize, and master the προαίρεσις. It’s not a moral failing, but a moral blindness.
Farewell.