Sure. There are at least two that show almost the same result. The first is most commonly cited:
Most people quit or learn to moderate on their own. The NIAAA’s 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions interviewed over 43,000 people. Using the criteria for alcohol dependence found in the DSM-IV, they found: "About 75 percent of persons who recover from alcohol dependence do so without seeking any kind of help, including specialty alcohol (rehab) programs and AA."
Another is from the Harvard Medical School (The Harvard Mental Health Letter, Volume 12, Number 4, October 1995, page 3):
'One recent study found that 80% of all alcoholics who recover for a year or more do so on their own, some after being unsuccessfully treated. When a group of these self-treated alcoholics was interviewed, 57% said they simply decided that alcohol was bad for them. Twenty-nine percent said health problems, frightening experiences, accidents, or blackouts persuaded them to quit. Others used such phrases as "Things were building up" or "I was sick and tired of it." Support from a husband or wife was important in sustaining the resolution.'