Background: While 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.
Methods: We 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.
Results: Hypersomnia 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.
Limitations: The study was retrospective, undertaken in a sample attending a tertiary referral unit and artefactual determinants of the associations were not pursued.
Conclusions: We 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.