Personality and Major Depression

TLDR

Neuroticism is a strong genetic indicator of major depression liability, yet it does not capture all genetic vulnerability, and extroversion shows only a weak relationship with depression risk. The study aimed to clarify the magnitude and nature of the association between neuroticism and extroversion and the risk for major depression. Using a longitudinal, population‑based Swedish twin cohort of 20,692 same‑sex twins, researchers assessed neuroticism and extroversion via self‑report in 1972–73 and interviewed participants more than 25 years later for lifetime DSM‑IV major depression. Twin modeling revealed that neuroticism’s association with major depression is largely due to.

Abstract

Prior studies suggest that the personality traits of neuroticism and extroversion may be related to the liability to major depression (MD).To clarify the magnitude and nature of the association between neuroticism and extroversion and the risk for MD.Longitudinal population-based twin cohort.General community.A total of 20 692 members of same-sex twin pairs from the population-based Swedish Twin Registry who completed a self-report questionnaire assessing neuroticism and extroversion in 1972 and 1973 and were personally interviewed for lifetime history of MD more than 25 years later.Main Outcome Measure Lifetime history of modified DSM-IV MD.Levels of neuroticism strongly predicted the risks for both lifetime and new-onset MD. Twin modeling indicated that the association between neuroticism and MD resulted largely from shared genetic risk factors, with a genetic correlation of +0.46 to +0.47. Levels of extroversion were weakly and inversely related to the risks for lifetime and new-onset MD. This effect disappeared when we controlled for the level of neuroticism. Twin modeling produced similar results.Results from both longitudinal and genetic analyses support the hypothesis that neuroticism strongly reflects the liability to MD. This association arises largely because neuroticism indexes the genetic risk for depressive illness. However, substantial proportions of the genetic vulnerability to MD are not reflected in neuroticism. By contrast, extroversion is only weakly related to risk for MD.