It seems that having too much of a good thing even applies to sleep.
New research from the University of Texas, in the United States, has found that sleeping nine hours or more per night is associated with worse cognitive performance, which is even more the case for those with depression.
Study senior author Sudha Seshadri said long, but not short sleep, duration was associated with poorer global cognition and specific cognitive abilities like memory, visuospatial skills and executive functions.
“These associations were stronger in people with depressive symptoms, regardless of antidepressant usage,” Dr Seshadri said.
She said there was increasing recognition of the significance of sleep as a vital physiological process for brain health.
Dr Seshadri said several studies had suggested that both excessive and insufficient sleep relative to the prescribed duration were linked to impairments in cognitive domains.
“However, evidence has been marked by inconsistencies depending on the lifespan being examined, and on health differences such as depression.”
She said in the new research, the scientists investigated whether depression modified the associations between sleep duration and cognitive performance.
“(We) found that long sleep was associated with reduced overall cognitive function, with the strongest effects in those with depressive symptoms using and not using antidepressants.”
Read the full study: Long sleep duration, cognitive performance, and the moderating role of depression: A cross-sectional analysis in the Framingham Heart Study.
