Sleep disturbance, personality and the onset of depression and anxiety: prospective cohort study.

OBJECTIVE

Previous studies have shown associations between sleep disturbance and the onset of depression and anxiety. However, this relationship may reflect an underlying vulnerability, such as temperament or cognitive style, which accounts for an association between the two. This study aimed to evaluate the relationship between sleep disturbance and the onset of a mental disorder after a 4-year follow-up, and whether this was accounted for by ruminative style and neuroticism.

METHOD

The nine-item Patient Health Questionnaire was used to assess the criteria for major depression, generalized anxiety disorder (GAD) and panic disorder (PD) in a community cohort of 3636 young and middle-aged Australian adults, free of any disorder at baseline, over a 4-year period. Sleep disturbance was based on a factor derived from the sleep items of the Goldberg Depression and Anxiety Scales. The associations between baseline sleep disturbance and a new episode of the assessed disorders were estimated and the impact of temperament and cognitive style on these associations was evaluated.

RESULTS

Self-reported sleep disturbance was significantly associated with an onset of major depressive disorder [MDD; odds ratio (OR) = 1.33, p = 0.006], GAD (OR = 1.37, p < 0.001) and PD (OR = 1.62, p < 0.001) after 4 years. However, the relationship for MDD was attenuated to nonsignificance (OR = 1.19, p = 0.116) after adjusting for neuroticism (measured by the Eysenck Personality Questionnaire-Revised) and rumination (measured by the adapted Ruminative Style scale).

CONCLUSIONS

These data suggest that the often-observed association between sleep disturbance and depression onset may be linked to an underlying ruminative style and/or neuroticism. However, the fact that the effect of sleep disturbance on PD and GAD onset was not accounted for by personality factors is a novel finding and suggests a potential role of early identification in selective preventive interventions.