Depression Not Linked To Genetics, Researchers Say

June 17, 2009 7:57 a.m. EST

San Francisco, CA (AHN) - In what is likely to be a disappointiment to many in the psychiatric community, a new analysis of previous studies finds no direct association between genetics and depression.

Researchers with the University of California at San Francisco and Kaiser Permanente Northern California Division of Research, Oakland, analyzed 14 previous studies researching the association between a serotonin transporter gene variation, stressful life events and an increased risk of major depression.

What they found contradicts a previous study embraced by many in the medical community from a few years ago that offered hope to mental health experts and sufferers of depression because it suggested there was a gene that caused depression and other psychiatric disorders.

"Few if any of the genes identified in candidate gene association studies of psychiatric disorders have withstood the test of replication and to date, genome-wide association studies of psychiatric disorders have also had limited success," the authors wrote in the study published in the June 17 edition of the Journal of the American Medical Association.

The authors did find that the amount of stressful events in a person's life is associated with depression.

The authors said the findings are particularly important because several clinical, legal, research and social theories are based on findings that major depression is caused by genetics. They stressed that the analysis reinforced the notion that replication is imperative to any scientific theory.