The correlation between pathological gambling and major depression in middle-aged men appears to be heavily influenced by overlapping genetic factors, according to a study by researchers at Yale School of Medicine and Washington University's School of Medicine.

The lead author, Marc Potenza, M.D., associate professor in the Department of Psychiatry, said future research is needed to determine if the findings extend to other groups, such as women, to identify specific relevant genes, and to generate improved prevention and treatment strategies.

He said important future studies involve determining which comes first-pathological gambling or depression-and how the disorders interact over time, and the extent to which treatments for one disorder might be helpful for both disorders.

The Vietnam-era Twin Registry was used as the basis for the study. Twin studies allow researchers to estimate the extent to which genetic makeup and environment contribute to psychiatric disorders. Comparisons can be made between identical, or monozygotic, twins, and fraternal, or dizygotic, twins. These studies already have identified a heritable component to pathological gambling and genetic overlaps between both pathological gambling and alcohol dependence and pathological gambling and antisocial behaviors.

"The data suggest a significant correlation between pathological gambling and major depression that is attributable largely to genetic factors," Potenza said. "This study highlights the importance of trying to identify specific genes that might contribute both to pathological gambling and major depression in order to improve treatment and prevention strategies."

The study was supported by grants from the National Institutes of Health and the U.S. Department of Veterans Affairs. Co-authors include Hong Xian, Kamini Shah, Jeffrey Scherrer, and Seth Eisen, M.D.