Depression and insomnia among adolescents: A prospective perspective

Background: No studies of adolescents have examined the prospective, reciprocal association between insomnia and major depression. Methods: A two-wave, community-based cohort of 3134 youths aged 11-17 at baseline. Major depression was assessed using DSM-IV criteria. Three measures of insomnia were used also following DSM-IV: P1, any symptom of insomnia; 132, any symptom plus impairment; P3, 132 with no comorbid mood, anxiety or substance use disorders. Results: In general, the association between insomnia and depression was stronger and more consistent for major depression than for symptoms of depression. Baseline insomnia (P1 and 132) increased subsequent risk of major depression 2-3-fold and P1 2-fold in multivariate analyses. Major depression increased risk for subsequent insomnia 2-3-fold for P1 and 132 2-fold for 132 in multivariate analyses. Results varied by measure of insomnia used. Limitations: Only symptoms of insomnia were assessed, so we could not examine the effects of comorbid sleep disorders nor did we have objective or biological measures of disturbed sleep. We also did not collect data on parental reports of youth depression nor insomnia or sleep problems. Conclusion: Our results provide the first prospective data on insomnia and major depression among adolescents indicating the two are reciprocally related. More studies are needed examining trajectories of insomnia and major depression in childhood and adolescence. (C) 2012 Elsevier B.V. All rights reserved.