Alcoholics anonymous effectiveness: faith meets science.

Research on the effectiveness of Alcoholics Anonymous (AA) is controversial and subject to widely divergent interpretations. The goal of this article is to provide a focused review of the literature on AA effectiveness that will allow readers to judge the evidence effectiveness of AA for themselves. The review organizes the research on AA effectiveness according to six criterion required for establishing causation: (1) magnitude of effect; (2) dose response effect; (3) consistent effect; (4) temporally accurate effects; (5) specific effects; (6) plausibility. The evidence for criteria 1- 4 and 6 is strong: rates of abstinence are about twice as high among those who attend AA (criteria 1, magnitude); higher levels of attendance are related to higher rates of abstinence (criteria 2, dose-response); these relationships are found for different samples and follow-up periods (criteria 3, consistency); prior AA attendance is predictive of subsequent abstinence (criteria 4, temporal); and mechanisms of action predicted by theories of behavior change are present in AA (criteria 6, plausibility). However, rigorous experimental evidence establishing the specificity of an effect for AA or Twelve Step Facilitation/TSF (criteria 5) is mixed, with 2 trials finding a positive effect for AA, 1 trial finding a negative effect for AA, and 1 trial finding a null effect. Studies addressing specificity using statistical approaches have had two contradictory findings, and two that reported significant effects for AA after adjusting for potential confounders such as motivation to change.