"Our research in an animal model establishes a causal link between abstinence from alcohol drinking and depression," study senior author Clyde W. Hodge, a professor of psychiatry and pharmacology in the University of North Carolina School of Medicine, said in a UNC news release. "In mice that voluntarily drank alcohol for 28 days, depression-like behavior was evident 14 days after termination of alcohol drinking. This suggests that people who stop drinking may experience negative mood states days or weeks after the alcohol has cleared their systems."

The research, published online in the journal Neuropsychopharmacology, also found that the mice developed a reduced capacity for the brain to produce new neurons, a process called neurogenesis. This lack of neuron production occurred in the hippocampus, an area critical for learning and memory.

Recent studies have also shown neuron development in the hippocampus may regulate mood, Hodge said.

"Thus, people who drink moderate alcohol socially, or for potential health benefits, may experience negative mood or diminished cognitive abilities due to a loss of the brain's ability to form new neurons," he said.

However, the researchers also found that treating the mice on the wagon for 14 days with an antidepressant prevented the depression and restored the brain's ability to produce new cells.

"Treatment with antidepressant drugs may help people who suffer from both alcoholism and depression by restoring the brain's ability to form new neurons," Hodge said. "Moreover, this research provides an animal model of alcohol-related depression with which we can begin to fully understand the neurobiology underlying co-occurring alcoholism and depression, and thereby develop successful treatment options."

Some scientific evidence has long suggested that moderate drinking may help prevent heart disease, certain types of stroke and some forms of cancer.