Researchers Identify Alcoholism Subtypes

A major challenge in alcoholism research has been to understand why some alcoholics improve with particular medications and psychotherapies while others don't. A new analysis of people with alcohol dependence by researchers at NIH's National Institute on Alcohol Abuse and Alcoholism (NIAAA) revealed 5 distinct subtypes of the disease. Understanding these subtypes will help researchers develop more effective prevention and treatment strategies for alcohol abuse.

Previous efforts to identify alcoholism subtypes focused mostly on people who were hospitalized or otherwise receiving treatment for their alcoholism. However, recent reports from NIAAA's National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) suggest that only about one-fourth of those with alcoholism have ever received treatment. An NIAAA research team led by Dr. Howard B. Moss applied advanced statistical methods to data from the NESARC, focusing on the 1,484 NESARC survey respondents who met diagnostic criteria for alcohol dependence. They published their results online on June 26, 2007, in the journal Drug and Alcohol Dependence.

The researchers were able to identify unique subtypes of alcoholism based on a family history of alcoholism, the age of onset of regular drinking and alcohol problems, symptom patterns of alcohol dependence and abuse, and the presence of additional substance abuse and mental disorders.

The largest cluster the researchers identified, which includes about 31% of U.S. alcoholics, comprises young adults who rarely seek help for their drinking and who have relatively low rates of other substance abuse or mental disorders and a low rate of family alcoholism. Next largest was the “young antisocial” subtype, comprising 21% of U.S. alcoholics. More than half of these come from families with alcoholism, and about half have a psychiatric diagnosis of antisocial personality disorder. Many have major depression, bipolar disorder and anxiety problems. More than 75% smoked cigarettes and marijuana, and many also had cocaine and opiate addictions. More than one-third of these alcoholics seek help for their drinking.

Continuing along these lines, the researchers defined 3 other subtypes of alcoholism. "Our findings should help dispel the popular notion of the ‘typical alcoholic,’” Moss notes. “We find that young adults comprise the largest group of alcoholics in this country, and nearly 20% of alcoholics are highly functional and well-educated with good incomes. More than half of the alcoholics in the United States have no multigenerational family history of the disease, suggesting that their form of alcoholism was unlikely to have genetic causes.”

The classification system the researchers developed will now help researchers to design and tailor more effective, personalized treatments for people with alcohol dependence.