Study Links Shorter Sleep Durations with Greater Risks of Mental Distress in Young Adults

Young adults who get fewer than eight hours of sleep per night have greater risks of psychological distress, a combination of high levels of depressive and anxious symptoms, according to a study in the Sept. 1 issue of the journal SLEEP.
Using an average self-reported nightly sleep duration of eight to nine hours as a reference, the study found a linear association between sleep durations of less than eight hours and psychological distress in young adults between 17 and 24 years of age. The risk of psychological distress increased by 14 percent for each hour of nightly sleep loss, such that those sleeping less than six hours a night were twice as likely to be experiencing distress as average sleepers. A similar association was found between sleep duration and persistent psychological distress; the risk that a person with psychological distress at baseline would be distressed at the one-year follow-up increased by five percent for each hour of nightly sleep loss after adjusting for potential confounders (RR 1.05). Long sleep durations of more than nine hours showed no association with distress at any time point.

“In young adults already experiencing distress, the fewer hours they sleep the worse the outcome across the range of sleep hours,” said lead author Nick Glozier, MBBS, MRCPsych, PhD, associate professor of psychological medicine at the Brain and Mind Research Institute and the Centre for Integrated Research and Understanding of Sleep (CIRUS) at the University of Sydney in Australia.

The study also found that the risk for the onset of psychological distress was increased only in those young adults with extremely short sleep durations. Participants without psychological distress at baseline who reported sleeping five hours or less per night were three times more likely to be distressed one year later (RR 3.25).

“Short sleep duration increases the risk of a new onset of distress only among the very shortest sleepers, and doesn’t appear to have a psychological impact in young adults in good mental health with moderately short sleep durations, such as seven hours a night” said Glozier.

In 2007 the U.S. Substance Abuse and Mental Health Services Administration estimated that 17.9 percent of young adults between the ages of 18 and 25 years experienced serious psychological distress in the past year. The Australian Bureau of Statistics reported that 26 percent of all young people between 16 and 24 years of age had a mental disorder in 2007.
Conducted at The George Institute for Global Health of the University of Sydney, the DRIVE study involved 20,822 young adults in New South Wales, Australia. Participants completed a confidential survey, reporting the number of hours slept on both weekday and weekend nights during the past month. The data were weighted to determine respondents’ average nightly sleep duration. Thirty percent of participants slept for seven to eight hours per night, and 18 percent reported sleeping less than seven hours. Fewer than two percent of study subjects had an extremely short sleep duration of less than five hours per night.