Sleeping in? The impact of age and depressive sub-type on hypersomnia

BackgroundWhile early morning wakening is held to be a classic feature of melancholia, we investigate the clinical observation that young patients with melancholia and bipolar depression tend to be more likely to report hypersomnia.MethodsWe examine age-related rates of those two sleep disturbance patterns in a consecutive set of out-patients with differing depressive sub-types assessed over a 20-year period.ResultsHypersomnia was more likely to be reported than early morning wakening across all age bands by those with non-melancholic depression. Hypersomnia was also more likely than early morning wakening in younger patients with melancholia and bipolar disorder but, with age, early morning wakening became the dominant pattern.LimitationsThe study was retrospective, undertaken in a sample attending a tertiary referral unit and artefactual determinants of the associations were not pursued.ConclusionsWe speculate that hypersomnia may be a non-specific homeostatic coping response to stress and thus to the non-melancholic depressive disorders, but that this pattern is overruled by an early morning wakening pattern in the more biological depressive sub-types as the individual ages, perhaps reflecting a noradrenergic contribution.