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Can poor sleep cause depression?

Last updated: October 15, 2026

Poor sleep is a strong risk factor. A meta-analysis of 21 long-term studies found that people with insomnia had about twice the risk of later developing depression compared with good sleepers. The link runs both ways.

The evidence

Eaton et al. (1995), using data from the US Epidemiologic Catchment Area program, estimated that sleep problems would flag 47% of the new cases of major depression that appeared in the following year. A later meta-analysis of 21 longitudinal studies (Baglioni et al., 2011) found that non-depressed people with insomnia had roughly a twofold risk of developing depression (pooled odds ratio 2.1 to 2.6).

The bidirectional loop

Sleep problems can both precede and result from depression. Franzen and Buysse (2008) review this two-way relationship: poor sleep raises the risk of depression, and depression in turn disturbs sleep.

What to do

Researchers suggest that treating insomnia early might reduce the risk of developing depression (Baglioni et al., 2011). A consistent schedule, enough sleep and good sleep habits are a sensible foundation, and if low mood or poor sleep lasts more than a couple of weeks, talk to a doctor.

Sources

1. Eaton et al., American Journal of Psychiatry, 1995. Prodromes and precursors: epidemiologic data for primary prevention of disorders with slow onset
2. Baglioni et al., Journal of Affective Disorders, 2011. Insomnia as a predictor of depression: a meta-analytic evaluation of longitudinal epidemiological studies
3. Franzen & Buysse, Dialogues in Clinical Neuroscience, 2008. Sleep disturbances and depression: risk relationships for subsequent depression and therapeutic implications