THE GENETICS OF DEPRESSION: EXPLORING THE ROLE OF TRAUMATIC ENVIRONMENTS

Exploring both the environmental and genetic risk factors for depression is essential if geneticists and epidemiologists can contribute to the improvements in healthcare for depression. In UK Biobank there are ~157K people... [ view full abstract ]

Exploring both the environmental and genetic risk factors for depression is essential if geneticists and epidemiologists can contribute to the improvements in healthcare for depression. In UK Biobank there are ~157K people who have completed a standardised questionnaire on common mental disorders that included 26 childhood and adult trauma items.  We compared the shared aetiology between depression and a range of phenotypes, contrasting individuals reporting trauma exposure with those who did not (final sample size range: 24,094- 92,957). Depression was heritable in participants reporting trauma exposure and in unexposed individuals, and the genetic correlation between depression in participants reporting trauma exposure and in unexposed individuals was substantial. Genetic correlations between depression and psychiatric traits were strong regardless of reported trauma exposure, whereas genetic correlations between depression and body mass index (and related phenotypes) were observed only in trauma exposed individuals. The homogeneity of genetic correlations in trauma unexposed depression and lack of correlation with BMI echoes earlier ideas of endogenous depression.