Is It In the Genes?

Driven to drink: Does alcoholism run in the family?

By PT Staff, published May 1, 1992 - last reviewed on June 9, 2016

Researchers have long known that alcoholism runs in families; in fact, studies show that 60% of alcoholics have at least one alcoholic parent. Yet whether the disease is caused by wayward genes or lost dreams remains a mystery. Studies say both sides may be right.

Alcoholics, it is now clear are not all of one kind. Investigators have found that, among men, there are at least two types -- those with early-onset abuse (prior to age 25), and those whose illness sets in later in life.

Researchers suspect that family incidence of alcoholism runs unusually high among early-onset alcoholics, suggesting a genetic predisposition. This group comprises 40% of the estimated million male alcoholics in the United States. Impulsivity and violent behavior are common among these men, who are motivated to seek alcohol is as a way to get high.

By contrast, men who become alcoholics later in life have less family involvement and use alcohol as a way to relieve anxiety and stress. (Women problem drinkers are more in keeping with the late-onset male pattern.)

The possibility that genetic makeup predisposes some men to alcoholism has sent scores of researchers scrambling to find the chromosomal culprit. One group of studies implicates a gene that affects the ability of brain cells to respond to dopamine--a neurochemical active in pleasure responses. Unable to get enough dopamine because they lack a sufficient number of receptors for it, the thinking goes, such people use alcohol as self-medication in an attempt to boost dopamine levels.

But other researchers point to evidence of a "mean gene" that impairs the action of serotonin, awide spread neurotransmitter that normally dampens many brain stimuli, including those wrought by dopamine.

So who's right? As researchers duke it out in the lab, Frederick K. Goodwin, M.D., sees sense in the seemingly contradictory findings. What it most likely means, says Goodwin, head of the National Institute of Mental Health, is that there may be more than a single gene involved in alcoholism, just as there is with diabetes. "There's no doubt it's a complex picture."

Dr. Goodwin suspects that future research may even turn up a common genetic predisposition to a complete host of addictions, including alcohol and drugs--perhaps even extending to food and sex. Then, he feels, yet another factor--genetic in some cases, perhaps environmental in others--would influence the specific form of the addiction.