Neuroticism: A vulnerability marker for depression evidence from a family study

Introduction: We investigated the relationship between depressive illness and personality traits from the Eysenck Personality Inventory (EPI) using data from a family study. Methods: The first-degree relatives of a series of 89 probands with RDC major depression (MD) were subdivided by their lifetime RDC diagnosis into: (1) relatives recovered from MD (n = 34); (2) never-ill relatives (n = 45). The neuroticism (N) and extraversion (E) scores of these two groups were compared using a multilevel linear model, allowing for potential confounders. The relationship between age of onset and recurrence of MD and N scores in group 1 was also examined. Results: (1) Raised N scores were associated with a past history of major depression. (2) There was no such relationship for E scores. (3) Current depressive symptoms were also associated with an increased N score but this did not explain the relationship between previous major depression and N scores, (4) Recurrent episodes of major depression in the recovered MD relatives;were significantly associated with increased N scores. Conclusion: These data suggest that raised N may be a vulnerability marker for major depression.