Actor Charlie Sheen's recent rambling rants included several tirades against the 12-step program popularized by Alcoholics Anonymous: He called it a "bootleg cult" and claimed it had only a 5% success rate.

While we're not believing much of what Sheen is spouting, that 5% statistic has people talking. Does the massively popular program really do that bad a job at combating alcohol abuse?

AA stats are hard to come by, since the organization doesn't conduct studies on itself. A 2007 membership survey reported that 33% of members said they'd been consistently sober for more than 10 years, 12% were sober for five to 10 years, 24% were sober for one to five years, and 31% were sober for less than one year. However, the numbers don't reveal the total number of years the members have been in the program.

Addiction specialists cite numbers closer to 8% to 12% for sobriety by members after the first year. Even Dr. Drew Pinsky of "Celebrity Rehab" acknowledged that Sheen's statement had some cred. "He's got a point," Pinsky said to TMZ recently. "Their success rates aren't that great. But the fact is, it does work when people do it."

A Cochrane Review that combined studies looking at AA and other 12-step programs found 12-step programs weren't any more effective in decreasing alcohol abuse compared with other treatments, although researchers found limitations with some of the studies.

Some research presents a rosier picture. A 2007 study in the journal Alcoholism: Clinical and Experimental Research discovered that those in 12-step treatment programs had a 49.5% abstinence rate after one year, while those who were in cognitive behavioral therapy programs had a 37% abstinence rate.

A small study published online in the journal Addictive Behaviors in 2002 found that among 56 people who finished an in-patient AA treatment program, about half were employed or productive, socially stable and abstinent after two years.

Addiction specialists we spoke with were quick to praise AA, we should add. They say the organization has many benefits -- and that addiction in general is extremely hard to treat successfully. AA and other similar 12-step programs are usually better than no treatment at all, they say. A 2006 study in the Journal of Clinical Psychology found that among 628 people, those who took part in AA for 27 weeks or more had better 16-year outcomes for such factors as abstinence and good social functioning than those who had no treatment.

"If it was such a dismal program," says Dr. Karen Miotto, medical director of the UCLA Addiction Medicine Service and an addiction psychiatrist, "it would be hard to understand why millions of people around the world are involved with it."

Added Dr. David Sack, chief executive of Promises Treatment Centers and an addiction psychiatrist, AA's success stats, if they compile them, may not be what the group wants to share or emphasize: "AA is a self-help support group, it wasn't designed as a treatment," he says.

What AA offers is important, Sack adds: "One of the core features of AA is getting a sponsor, a peer who has had more time in recovery and can teach you about the AA approach to addiction. In studies that have looked at AA, having a sponsor significantly improves the likelihood of long-term abstinence."

Another core value is service to others, something that helps people reclaim their self-esteem, Sack says. "Addicts often feel sub-human, and this helps them restore their sense of self-worth and become part of the human family through that process."

While a 12-step program like AA may help an addict get and stay sober, it is hardly the only tool in the addiction recovery arsenal, and certain types of addictions may require more intensive treatment. Many people pair 12-step meetings with in- or out-patient treatment programs, cognitive behavioral therapy and medications that help the body cope with withdrawal. No one-size-fits-all therapy works; Miotto says that has to be determined individual by individual and depends on a number of factors:

"Do they need detox, and can that be done on an in-patient basis? Do people need a higher level of structure, like rehabilitation? A lot of that depends on their level of motivation, their recovery skills, if they have a sober environment and support, and their level of physical, mental and spiritual health."

Even with other programs in place, relapse levels are often high. How often do we see celebs in the news for going to rehab, only to fall off the wagon, go back to rehab and continue the sober-using cycle?

"With a treatment like cognitive behavioral therapy," Miotto says, "we lose 50% of participants the first week of treatment. That's good for a disease like this."

Miotto isn't really worried that Sheen's widely publicized rants will deter people from going to a 12-step meeting.

"I think the more people talk about addiction and ask questions about what [AA] is and how it works, the better," she says. "Sometimes having adverse role models can bring attention to the matter.

"And maybe three years from now he'll be the poster boy for 12-step programs. There have certainly been other actors who have been portrayed as bad boys who are active now in recovery programs."