Because addiction is a socially isolating disease, social support for recovery is an important element of treatment planning. This study examines the relationship between social isolation, giving and receiving social support in Alcoholics Anonymous during treatment, and post-treatment outcomes among juvenile offenders court-referred to addiction treatment. Adolescents (N = 195) aged 14 to 18 years were prospectively assessed at treatment admission, treatment discharge, 6 months, and 12 months after treatment discharge. The influence of social isolation variables on relapse and severe criminal activity in the 12-months post-treatment was examined using negative binomial logistic regressions and event history methods. Juveniles entering treatment with social estrangement were significantly more likely to relapse, be incarcerated, and commit a violent crime in the 12-months post-treatment. Giving help to others in Alcoholics Anonymous during treatment significantly reduced the risk of relapse, incarceration, and violent crime in the 12-months post-treatment whereas receiving help did not.