Introduction: We investigated whether depression modified the associations between sleep duration and cognitive performance.
Methods: Multivariable linear regression models examined the associations between sleep duration and cognition in 1,853 dementia- and stroke-free participants from the Framingham Heart Study. Participants were categorized in four groups: no depressive symptoms, no antidepressants; depressive symptoms without antidepressants use; antidepressant use without depressive symptoms; both depressive symptoms and antidepressant use.
Results: Long sleep was associated with reduced overall cognitive function. Strong associations between sleep duration and cognitive performance were found in individuals with depressive symptoms, regardless of antidepressant use. Weaker but significant effects were observed in those without depressive symptoms. No significant associations were observed in participants using antidepressants without depressive symptoms.
Discussion: These findings provide new evidence that sleep duration may be a modifiable risk factor for cognitive decline, particularly in individuals with depressive symptoms. Future research should elucidate underlying mechanisms and temporal relationships.
Keywords: Cognitive function; Depression; Sleep duration.