Insomnia as a predictor of mental disorders: A systematic review and meta-analysis

Summary Previous research has identified insomnia as a predictor for the onset of depression. The aim of this meta-analysis is to investigate whether insomnia also predicts the onset of other mental disorders. Longitudinal studies were eligible for inclusion if they investigated insomnia at baseline (including nighttime- and daytime-symptoms) as a predictor of the later onset of psychopathology within a follow-up time-frame of at least 12 mo. Thirteen primary studies were included. The results suggest that insomnia is a significant predictor for the onset of depression (10 studies, OR 2.83, CI 1.55–5.17), anxiety (six studies, OR 3.23, CI 1.52–6.85), alcohol abuse (two studies, OR 1.35, CI 1.08–1.67, and psychosis (one study, OR 1.28, CI 1.03–1.59). The overall risk of bias in the primary studies was moderate. This meta-analysis provides evidence that insomnia increases the risk for psychopathology. A future research agenda should include more prospective studies using established diagnostic criteria, assessing insomnia at baseline and including long-term follow-up intervals evaluating a wider range of mental disorders. In addition, prospective long-term interventional studies investigating the efficacy of insomnia treatment for the prevention of mental disorders are called for.