PROJECT SUMMARY Alcohol use disorder (AUD) is prevalent and costly, and associated with significant morbidity and mortality. Effective pharmacological and psychosocial treatments for AUD exist, although many individuals do not receive medications and most are treated via mutual support group participation. Alcoholics Anonymous and other mutual support programs have been shown to be highly effective in supporting abstinence, and they are a tremendously valuable option for those interested in abstinence-based recovery. Yet, approximately 80% of individuals with AUD never seek treatment and not wanting to stop drinking is a common barrier to seeking treatment. AA and other mutual support programs are often abstinence-based, yet programs that focus on reductions in drinking have been shown to be as effective at reducing harms related to alcohol use. Recent studies in population-based and clinical samples indicate significant health benefit from drinking reductions, without total abstinence. Aligned with these findings, the National Institute on Alcohol Abuse and Alcoholism has proposed a new operational definition of recovery defined as: remission from AUD, cessation of heavy drinking, and improvements in functioning and well-being. Expanding the definition of recovery to include non- abstinent outcomes could increase treatment seeking among those with AUD who are not willing to abstain but are willing to reduce drinking, and reduce the public health burden of untreated AUD. One program that has considerable promise for promoting AUD recovery is mindfulness-based relapse prevention (MBRP). Efficacy of MBRP for reducing heavy drinking has been shown in several trials. Further, MBRP explicitly targets neurobiologically-informed domains of addiction: inhibitory control over behavioral responses (executive function); craving and cue reactivity (incentive salience); and negative affect (negative emotionality). MBRP may also be more effective than existing continuing care options in targeting broader health and life functioning. MBRP also has the potential to be broadly accessible via video conferencing. The goal of this study is to examine the effectiveness of MBRP groups delivered via video conferencing in promoting whole- person recovery from AUD up to three years following an attempt to change or stop drinking via treatment or self-change, as compared to referral to online mutual support groups. This study will also examine how MBRP affects mechanisms of behavior change based on neurobiologically-informed addiction cycle domains. We will use an effectiveness-implementation design to prospectively test the effectiveness of MBRP, as well as identify barriers and facilitators of MBRP group participation to inform future implementation of MBRP continuing care. The ultimate goal of this work is to evaluate MBRP via video conferencing as a continuing care option that supports whole-person recovery and targets addiction cycle domains in supporting long-term r...