Genetic Link to Depression Identified




Many studies have shown a heritable component to depressive disorders, but a specific cause has not been identified. Recently, scientists in two separate studies located a specific chromosomal region that is associated with depression.

Both studies were recently published in the American Journal of Psychiatry. One study was led by a team at Washington University in St. Louis and evaluated families who had diagnoses of major depressive disorder (MDD). In all, there were 91 Australian families with two or more siblings with MDD and 25 Finnish families with siblings affected with MDD. The second study, conducted primarily in the United Kingdom, evaluated 839 families with siblings pairs diagnosed with severe recurrent MDD. In a rare scientific occurrence, both studies reported that the same gene was associated with MDD, a region on chromosome 3 known as 3p25-26.

Replication of findings like this usually takes years, especially in genome-wide studies, if it is ever accomplished at all. The fact that both research teams simultaneously replicated each other’s findings is astounding — and promising. Researchers and clinicians alike hope that this new evidence will prompt new gene-based therapies to treat depression. Currently available medications for depression are only effective in about half of patients.

Previous studies of depression have indicated that depressive disorders are influenced by genetics, environmental factors, and external factors, and the interactions among them. The genetic component likely accounts for a little less than half of the risk of developing depression. Many genes are involved, in addition to 3p25-26. Further studies are necessary to identify more genes, and external factors, that influence depression.

MDD affects nearly 20% of people at some point in their lives. It is a costly and potentially debilitating condition. Personalized and individualized pharmacotherapy and psychotherapy are the cornerstones of the successful treatment of depression. Each piece of evidence that points to an identifiable cause of this disorder is one step closer to more effective treatment options.

References

Breen G, Webb BT, Butler AW, van den Oord EJ, Tozzi F, Craddock N, Gill M, Korszun A, Maier W, Middleton L, Mors O, Owen MJ, Cohen-Woods S, Perry J, Galwey NW, Upmanyu R, Craig I, Lewis CM, Ng M, Brewster S, Preisig M, Rietschel M, Jones L, Knight J, Rice J, Muglia P, Farmer AE, & McGuffin P (2011). A Genome-Wide Significant Linkage for Severe Depression on Chromosome 3: The Depression Network Study. The American journal of psychiatry PMID: 21572164

Lewis CM, Ng MY, Butler AW, Cohen-Woods S, Uher R, Pirlo K, Weale ME, Schosser A, Paredes UM, Rivera M, Craddock N, Owen MJ, Jones L, Jones I, Korszun A, Aitchison KJ, Shi J, Quinn JP, Mackenzie A, Vollenweider P, Waeber G, Heath S, Lathrop M, Muglia P, Barnes MR, Whittaker JC, Tozzi F, Holsboer F, Preisig M, Farmer AE, Breen G, Craig IW, & McGuffin P (2010). Genome-wide association study of major recurrent depression in the U.K. population. The American journal of psychiatry, 167 (8), 949-57 PMID: 20516156

Pergadia ML, Glowinski AL, Wray NR, Agrawal A, Saccone SF, Loukola A, Broms U, Korhonen T, Penninx BW, Grant JD, Nelson EC, Henders AK, Schrage AJ, Chou YL, Keskitalo-Vuokko K, Zhu Q, Gordon SD, Vink JM, de Geus EJ, Macgregor S, Liu JZ, Willemsen G, Medland SE, Boomsma DI, Montgomery GW, Rice JP, Goate AM, Heath AC, Kaprio J, Martin NG, & Madden PA (2011). A 3p26-3p25 Genetic Linkage Finding for DSM-IV Major Depression in Heavy Smoking Families. The American journal of psychiatry PMID: 21572167

Shi J, Potash JB, Knowles JA, Weissman MM, Coryell W, Scheftner WA, Lawson WB, DePaulo JR Jr, Gejman PV, Sanders AR, Johnson JK, Adams P, Chaudhury S, Jancic D, Evgrafov O, Zvinyatskovskiy A, Ertman N, Gladis M, Neimanas K, Goodell M, Hale N, Ney N, Verma R, Mirel D, Holmans P, & Levinson DF (2011). Genome-wide association study of recurrent early-onset major depressive disorder. Molecular psychiatry, 16 (2), 193-201 PMID: 20125088

Uher R (2011). Genes, environment, and individual differences in responding to treatment for depression. Harvard review of psychiatry, 19 (3), 109-24 PMID: 21631158

Wray NR, Pergadia ML, Blackwood DH, Penninx BW, Gordon SD, Nyholt DR, Ripke S, Macintyre DJ, McGhee KA, Maclean AW, Smit JH, Hottenga JJ, Willemsen G, Middeldorp CM, de Geus EJ, Lewis CM, McGuffin P, Hickie IB, van den Oord EJ, Liu JZ, Macgregor S, McEvoy BP, Byrne EM, Medland SE, Statham DJ, Henders AK, Heath AC, Montgomery GW, Martin NG, Boomsma DI, Madden PA, & Sullivan PF (2010). Genome-wide association study of major depressive disorder: new results, meta-analysis, and lessons learned. Molecular psychiatry PMID: 21042317

  • Adeyera

    I know depressive disorders are influenced by genetics, environmental factors, and external factors.but genetic link to depression is what I did not know.This is a good news,I believe it will help in curing depression.Thanks for this excellent article.

  • David

    This sounds extremely promising!

    Even though the possibility to eliminate the genetic factor of depression probably still lies quite far in the future (especially since many other genes are involved), this does sound like quite a breakthrough!

Jennifer Gibson, PharmD

Jennifer Gibson, PharmD, is a practicing clinical pharmacist and medical writer/editor with experience in researching and preparing scientific publications, developing public relations materials, creating educational resources and presentations, and editing technical manuscripts. She is the owner of Excalibur Scientific, LLC.
See All Posts By The Author

Do not miss out ever again. Subscribe to get our newsletter delivered to your inbox a few times a month.