Some quick bookmarks:
https://www.drugabuse.gov/.../behavioral-4
"the efficacy of 12-step programs (and 12-step facilitation) in treating alcohol dependence has been established"
http://www.scientificamerican.com/article/does-alcoholics-anonymous-work/
"the results of one well-designed investigation called Project Match,
published in 1997, suggest that AA can facilitate the transition to
sobriety for many alcoholics"
"research suggests that AA is quite a bit better than receiving no help [...] Of those who attended at least 27 weeks of AA meetings during the first
year, 67 percent were abstinent at the 16-year follow-up, compared with
34 percent of those who did not participate in AA"
http://alcalc.oxfordjournals.org/.../421.long
"Frequent AA attenders had superior drinking outcomes to non-AA attenders and infrequent attenders."