The discovery of 15 regions of the genome associated with major depressive disorder (MDD) in individuals of European descent is reported in a study published online this week in Nature Genetics. The study represents the first significant genetic associations with MDD in non-Asian individuals and may lead to further understanding of the biology of this disorder.
MDD causes severe symptoms including depressed mood, altered sleep patterns, appetite changes and fatigue. It is one of the most common mental health disorders. Although there is strong evidence that MDD has a genetic component, including a recent study in Han Chinese women that identified two genetic variants significantly associated with MDD, studies in individuals of European ancestry have not yet identified any genetic regions significantly associated with the disorder.
David Hinds, Roy Perlis, Ashley Winslow and colleagues conducted a genome-wide association study in more than 121,000 individuals reporting prior clinical diagnosis or treatment for MDD and more than 338,000 individuals reporting no history of depression. All study participants were customers of a consumer genomics company who had volunteered to participate in the company's research initiative. The authors identified 15 genomic regions that showed statistically significant associations with MDD. A preliminary analysis found that the 15 regions are enriched for genes that are expressed in the nervous system as well as genes involved in neurodevelopment. The researchers also found some overlap between the loci identified for MDD and those previously identified for other psychiatric disorders, including schizophrenia.