Addiction is a biopsychosocial disorder, meaning there are biological, psychological, & social factors that contribute to its predisposition & manifestation. Any treatment that does not address these three prongs will not succeed. For example, a purely pharmacological treatment that does not address the social condition of unaffordable housing is unlikely to lead to contiguous recovery.

This is why addiction, especially substance use disorder [SUD], is nefariously difficult to treat & prevent. It is inherently extremely complex & requires the cooperation of many often disarticulated fields [social work, psychiatry/psychology, medicine, &c.]. The U.S. does not have a robust system in place to adequately foster this type of multipronged treatment, but it should.

The best way to prevent addiction from manifesting would be to address the social conditions that often surround it: poverty, precarity, lack of social support, social isolation, &c. The best way to treat addiction would be to make treatment more accessible [read: free] & for treatment to include raising a person's social circumstances rather than simply isolating them in a treatment facility for 30-90 days & then dropping them back into the same conditions where the addiction developed in the first place.

source: I am working on my Ph.D. in sociology & addiction studies & have 10, hard fought, years of sobriety.