We also used to lock away basically any form of ASD or neurodivergence too far outside the norm (either directly via mental institutions, or indirectly via other harmful programs, mistreatment, or junk science). We also used to consider homosexuality a mental disorder. Moving forward is what society does.

Addiction is largely driven by neurodevelopmental disorders (ADHD, ASD, MDD, sleep disorders, and many more), psychological disorders (anxiety, OCD, and many more), or both in combination. Most folks don't want to be addicts. At the heart of addiction is executive dysfunction caused by the above conditions, exacerbated by stressors. You treat it like any other mental health problem: therapy, medication, support systems, and a society that cares for its populace.

Provide tools, strategies, and alternatives. They still have to use them (it can't be forced), but it's definitely possible to smooth the path. For example, if you have a friend who is trying to quit drinking, invite them to fun alcohol-free events.