When Alcoholics Anonymous and other 12-step programs are examined in controlled studies, a new review reports, scientists find no proof that they are superior to any other intervention in reducing alcohol dependence or alcohol-related problems.

The researchers, led by Marica Ferri of the Italian Agency for Public Health in Rome, found little to suggest that 12-step programs reduced the severity of addiction any more than any other intervention. And no data showed that 12-step interventions were any more — or any less — successful in increasing the number of people who stayed in treatment or reducing the number who relapsed after being sober.

Alcoholics Anonymous is a self-help group that offers emotional support for alcohol abstinence and holds that alcoholism is a spiritual and a medical disease.

In some of the studies reviewed, A.A. was compared with other psychological treatments including cognitive-behavioral therapy, which encourages the conscious identification of high-risk situations for alcohol use; motivational enhancement therapy, based on principles of social and cognitive psychology; and relapse prevention therapy, a variation on the cognitive-behavioral approach. It was also compared with other spiritual and nonspiritual 12-step programs.