Now, researchers have demonstrated that after recovery, the brains of people suffering from alcoholism still process things differently, which may lead to difficulties recognizing emotions in others.
The researchers looked at brain scans of 15 former alcoholics and 15 people without a history of alcoholism, and found that the former alcoholics did not register strong responses when shown images of people displaying positive or negative emotions the way the others did.
"The upshot, really, is that people who have had serious alcoholism problems sometime in the past, they could be misreading facial cues," said Ksenija Marinkovic, assistant professor in residence in the radiology department at the University of California, San Diego. "Not everybody is able to read facial cues in the same way."
The focus of the Boston-based study -- funded in part by the National Institute on Alcohol Abuse and Alcoholism, and the U.S. Department of Veterans Affairs -- was on finding the regions of the brain that might be altered in people who had an alcohol addiction.
"Even though we have known for quite some time ... that abstinent chronic alcoholics have cognitive problems, only behavioral studies have been done to show they have deficits in emotional functioning," said Marinkovic.
Researchers performed a number of cognitive tasks on the patients, including showing them pictures of faces with different expressions. Patients without a history of alcoholism had different responses -- shown by activity in the area of the brain known as the amygdala -- based on whether the picture showed a positive, negative or neutral expression. In those with a history of alcoholism, however, researchers saw no such differences.
"I think it puts some insight into why people who are alcoholics have these behavioral problems," said Dr. Wendy Wright, an assistant professor of neurology and neurosurgery at Emory University. "It adds more of an understanding with how we learn about alcoholics and how we learn to treat the disease."
While she said the problems presented here do not appear reversible, they could likely help people involved with the treatment of alcoholics.
"If you don't understand where someone's coming from and what type of challenges they're having, it's a lot more difficult to teach them how to cope," said Wright, comparing it with the difficulty faced by teachers of dyslexic students before they understood how dyslexia affected a child's ability to read.
While the study showed deficits in facial reading among recovered alcoholics, the small number of subjects means that the study could not answer the question of whether the problem is a result of alcoholism or whether people who become alcoholics already had difficulty with facial cues.
Marinkovic noted that while subjects were matched for age, I.Q. and moods, "they did differ significantly with respect to the family history of alcoholism."
"Alcoholism is a complicated syndrome, and we know there is also a genetic component," she said. "Alcohol itself has deleterious effects on the brain; nevertheless, this could be part of a pre-existing syndrome. This may precede alcohol abuse, and could be a part of a wider array of these problems."
Wright indicated that determining which came first would probably prove to be difficult.