Healthier sleep behaviors were associated with substantially lower risks of depression and suicidal ideation among U.S. adults, researchers reported. Participants with the highest composite sleep score (score of 4) had 88% lower odds of depression and 80% lower odds of suicidal ideation compared with those with the lowest scores (0-1). Depression explained about one-third of the association between sleep and suicidal ideation.
The analysis included 5,978 adults from the 2005 to 2008 National Health and Nutrition Examination Survey (NHANES). Investigators constructed a four-item sleep score based on self-reported behaviors: sleeping 7 to 8 hours, absence of frequent insomnia, no snoring, and no excessive daytime sleepiness. One point was assigned for each healthy behavior. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9), and suicidal ideation was evaluated by its ninth item. Survey-weighted logistic regression models were used to examine associations.
Results showed a graded relationship between higher sleep scores and lower risks. Each one-point increase in the sleep score was associated with 52% lower odds of depression and 42% lower odds of suicidal ideation. Sleeping 7 to 8 hours, not reporting insomnia, and not experiencing daytime sleepiness were each independently linked to reduced risks. Snoring was associated with a lower risk of suicidal ideation but was not related to depression after adjustment. Findings remained consistent across age, sex, and activity subgroups. Results also held following sensitivity analyses that excluded or adjusted for patients using antidepressants.
The study's authors note in their discussion that sleep problems may contribute to depression by disrupting the regulation of mood and emotions, affecting cognitive capacities, and diminishing coping skills.
The study had several limitations. Its cross-sectional design did not allow causal inference. Sleep behaviors were self-reported and may have been misclassified, particularly sleep duration, which is often overestimated in surveys. Suicidal ideation was measured with a single questionnaire item, and data on suicide attempts or mortality were not available. Residual confounding may also have influenced results.
The authors reported no conflicts of interest.
Source: Frontiers in Psychiatry
