&gt; Participation in AA is associated with substantially increased rates of continuous abstinence at the 1, 3 and 5 year marks after quitting<p>It&#x27;s been shown, as much as is possible, that that&#x27;s all selection bias.  People rarely fall off the wagon and then keep going to meetings.<p>AA&#x27;s rules around anonymity and consent make it conveniently impossible to run good studies, so they are able to (rightly, for the most part) write off any study that runs against them, but are also unable to show any positive findings that don&#x27;t fall prey to very obvious problems.