Shillong, October 20: A recent genetic study suggests that consistently sleeping less than five hours a night may increase the risk of developing depressive symptoms.
As per IANS, researchers from University College London (UCL) conducted this study, revealing that both sleep duration and depression have genetic components passed from one generation to the next.
The study, featured in the journal Translational Psychiatry, analyzed data from individuals with an average age of 65 and found a clear association between short sleep and the onset of depressive symptoms.
Lead author Odessa S. Hamilton explained, “Using genetic susceptibility to disease we determined that sleep likely precedes depressive symptoms, rather than the inverse.”
To conduct the study, researchers utilized genetic and health data from 7,146 individuals recruited by the English Longitudinal Study of Ageing (ELSA), a nationally representative population study in England.
They observed that individuals with a stronger genetic predisposition for short sleep (less than five hours per night) were more likely to develop depressive symptoms over a span of 4-12 years. However, a greater genetic predisposition to depression did not lead to an increased likelihood of short sleep.
Short and long sleep durations, along with depression, contribute significantly to public health burdens and have a strong genetic component.
Dr. Olesya Ajnakina, the senior author, noted, “Polygenic scores, indices of an individual’s genetic propensity for a trait, are thought to be key in beginning to understand the nature of sleep duration and depressive symptoms.”
The research team also examined non-genetic associations between depressive symptoms and sleep duration. They found that individuals sleeping five hours or less were 2.5 times more likely to develop depressive symptoms.
Conversely, those with depressive symptoms were a third more likely to experience short sleep. The study accounted for various factors that could influence the results, such as education, wealth, smoking status, physical activity, and chronic illness.
Furthermore, the researchers identified a connection between sleeping for extended periods and the development of depressive symptoms. Participants who slept longer than nine hours were 1.5 times more likely to experience depressive symptoms compared to those who slept an average of seven hours.
However, depressive symptoms were not associated with longer sleep durations four to 12 years later, aligning with the genetic findings.
Professor Andrew Steptoe emphasized the importance of understanding the link between depression and inadequate sleep, especially as both conditions become more prevalent with aging populations worldwide.