Gene plus stress equals depression debate
A combined analysis of 14 studies disputes the idea that a particular gene variant interacts with stressful experiences to promote depression
By Bruce Bower
The last thing depression investigators need is another dead-end research downer. Efforts to find genes that directly contribute to depression have come up empty. And a research team now concludes, after a closer inspection of accumulated research, that a gene variant initially tagged as a depression promoter when accompanied by stressful experiences actually has no such effect.
By showing that follow-up studies collectively don’t support the study that launched this line of research, two new analyses debunk the proposed pathway to depression. The chances of becoming depressed rise as stressful events mount, regardless of genetic makeup, report statistical geneticist Neil Risch of the University of California, San Francisco, and his colleagues.
The new studies, published together in the June 17 Journal of the American Medical Association, also demonstrate the difficulty of replicating reports of any gene variants that appear to work with environmental triggers to foster psychiatric disorders. Individual studies typically lack the statistical power to detect gene-by-environment interactions correctly because most candidate genes and stressful events exert modest effects on mental ailments at best, the scientists say.