The Genetics of Depression

Scientists find DNA linked to depression

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) It's long been thought that depression runs in families. New research strengthens the theory that genes do in fact  play a major role in this mental illness.

In an exciting coincidence, two groups of researchers who were working and studying separately, have discovered DNA on one chromosome that seems to be related to depression. The recently published studies found that family members each had the same genetic patterns.

Teams from Washington University School of Medicine in St. Louis and King’s College London have made this significant find that will advance the understanding of depression.

"Genetic discovery shows depression runs in families."

“What’s remarkable is that both groups found exactly the same region in two separate studies,” says senior investigator Pamela A. F. Madden, PhD, professor of psychiatry at Washington University. “We were working independently and not collaborating on any level, but as we looked for ways to replicate our findings, the group in London contacted us to say, ‘We have the same linkage peak, and it’s significant.’”

Researchers studied families in different parts of the world. And while the teams used different data, gathered in different ways and studied for different purposes, they both came up with the same results. They found what's known as a "linkage peak" on chromosome 3.

In both studies, depressed siblings carried many of the same gene patterns in that particular DNA region.

“These findings are truly exciting,” says Gerome Breen, PhD, lead author of the King’s College London study. “For the first time, we have found a genetic region associated with depression, and what makes the findings striking is the similarity of the results between our studies.”

While the researchers said these findings are "groundbreaking,: they are only a piece of the genetic puzzle and more work lies ahead.

Both studies are published the May 16, 2011 edition of the American Journal of Psychiatry.

The Study

  • Researchers at King’s College London followed more than 800 families in the UK affected by recurrent depression
  • The Washington University group gathered data from 91 families in Australia and another 25 families in Finland
  • Some of the study participants were heavy smokers, a known risk factor for depression
  • Using two different data sets, gathered and studied differently, both teams found what is known as a linkage peak on chromosome 3
  • Depressed siblings in both studies carried many of the same genetic variations in that particular DNA region
Reviewed by: 
Review Date: 
May 18, 2011
Last Updated:
May 20, 2011