Genetic Predisposition for Short Sleep Linked With Future Depression Onset
A genetic predisposition to sleeping fewer than 5 hours a night was strongly associated with depression onset over an average 8 years of follow-up in adults 50 years and older, according to a study published in Translational Psychiatry.
“However, polygenic predisposition to depression was not associated with overall sleep duration, short-sleep, or long-sleep, suggesting different mechanisms underlie the relationship between depression and the subsequent onset of suboptimal sleep durations in older adults,” wrote lead and corresponding author Odessa S. Hamilton, MSc, MBPsS, FRSPH, a doctoral researcher at University College London in the United Kingdom, and study coauthors.
>>NEWS: Regular Snoozers Appear to Benefit From Putting Off Morning Rise
The study included 7146 adults, aged 65 on average, from the English Longitudinal Study of Aging (ELSA). Researchers used summary statistics from genome-wide association studies to calculate participants’ polygenic scores. ELSA surveys provided data on sleep duration, which researchers categorized as short (fewer than 5 hours), optimal (between 5 and up to 9 hours), or long (9 or more hours) sleep, as well as subclinical depression, which was defined as a score of 4 or higher on the Center for Epidemiological Studies Depression Scale.
The study’s follow-up period spanned 4 to 12 years, with an average of 8 years.
According to study results, a 1 standard deviation increase in polygenic score for short sleep at baseline was associated with 14% increased odds of developing depression over follow-up. Polygenic predisposition to long sleep, on the other hand, was not associated with depression onset.
Additionally, the study found that increases in polygenic scores for depression were neither associated with short nor long sleep onset over follow-up.
“We have this chicken-or-egg scenario between suboptimal sleep duration and depression. They frequently co-occur, but which comes first is largely unresolved,” Hamilton said. “Using genetic susceptibility to disease, we determined that sleep likely precedes depressive symptoms, rather than the inverse.”
References
