The National Institute on Alcohol Abuse and Alcoholism (NIAAA), a part of the U.S. National Institutes of Health (NIH), has identified five distinct subtypes of alcoholism by analysing a national sample of individuals suffering from alcohol dependence.
"Our findings should help dispel the popular notion of the 'typical alcoholic,'" notes first author Dr. Howard B. Moss, NIAAA Associate Director for Clinical and Translational Research.
"We find that young adults comprise the largest group of alcoholics in this country, and nearly 20 per cent 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," he adds.
NIAAA Director Dr. Ting-Kai Li says that the study, published online in the Journal Drug and Alcohol Dependence, was an attempt by the researchers to understand why some alcoholics improve with specific medications and psychotherapies, while others do not.
"Clinicians have long recognized diverse manifestations of alcoholism, and researchers have tried to understand why some alcoholics improve with specific medications and psychotherapies while others do not. The classification system described in this study will have broad application in both clinical and research settings," Dr. Li says.
The researchers say that the five alcoholism subtypes identified were Young Adult subtype (31.5 per cent of U.S. alcoholics), Young Antisocial subtype (21 per cent), Functional subtype (19.5 per cent), Intermediate Familial subtype (19 per cent), and Chronic Severe subtype (9 per cent).
They gathered information about individuals with alcoholism by conducting the National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a nationally representative epidemiological study of alcohol, drug, and mental disorders. It suggested that only about one-fourth of individuals with the condition had ever received treatment.
The findings clearly indicate that the previous studies carried out to identify alcoholism subtypes would not have represented a substantial proportion of people with alcoholism in the samples used for them, as those projects focused primarily on individuals who were hospitalised or otherwise receiving treatment for alcoholism.
Young Adult subtype included young adult drinkers with relatively low rates of co-occurring substance abuse and other mental disorders, a low rate of family alcoholism, and who rarely seek any kind of help for their drinking.
Young Antisocial alcoholics were in their mid-twenties, had early onset of regular drinking, and alcohol problems. More than half of them came from families with alcoholism, and about half had a psychiatric diagnosis of Antisocial Personality Disorder. Many had major depression, bipolar disorder, and anxiety problems, and over 75 per cent smoked cigarettes and marijuana, and many also had cocaine and opiate addictions. More than one-third of them sought help for their drinking.
Functional alcoholics were typically middle-aged, well-educated people with stable jobs and families. About one-third of them had a multigenerational family history of alcoholism, about one-quarter had major depressive illness sometime in their lives, and nearly 50 per cent were smokers.
Intermediate Familial alcoholics were middle-aged people with about 50 per cent from families with multigenerational alcoholism. Almost half of them had had clinical depression, and 20 per cent bipolar disorder. Most of them smoked cigarettes, and nearly one in five had problems with cocaine and marijuana use. Only 25 per cent ever sought treatment for their problem drinking.
Chronic Severe alcoholics comprised mostly of middle-aged individuals who had early onset of drinking and alcohol problems, with high rates of Antisocial Personality Disorder and criminality. Almost 80 per cent of them came from families with multigenerational alcoholism. They had the highest rates of other psychiatric disorders, and two-thirds of them had sought help for drinking problems.
The researchers also report that co-occurring psychiatric and other substance abuse problems are associated with severity of alcoholism and entering into treatment.