Irregular sleep patterns associated with bad moods and depression, study shows

An irregular sleep program can increase a person’s risk for depression in the long run, just like sleeping fewer hours, or staying up late most nights, a new study suggests.

Even if the next day is just about their mood, people whose waking hours vary from day to day can feel just as bad as those who stayed up extra late the night before, or got up extra early in the morning, the study shows.

The study, conducted by a team from Michigan Medicine, the academic medical center of the University of Michigan, used data from direct measurements of sleep and mood of more than 2,100 early-career physicians over one year. It is published in npj Digital Medicine.

The trainees, as they are called in the first year of training after medical studies, all experienced the long intense working days and irregular work schedules that are the hallmark of this time in medical training. These factors, which change from day to day, have changed their ability to have regular sleep schedules.

The new article is based on data collected by detecting the sleep and other activities of the interns through commercial devices worn on their wrists, and asking them to report their daily mood in a smartphone app and do quarterly tests for signs of depression.

Those whose devices showed they had variable sleep schedules were more likely to score higher on standardized depression symptom questionnaires and get lower daily mood ratings. Those who stay up late regularly or sleep the least hours also have higher on depressive symptoms and lower on the daily mood. The findings contribute to what is already known about the link between sleep, daily mood and long-term risk of depression.

“The advanced portable technology enables us to study the behavioral and physiological factors of mental health, including sleep, on a much larger scale and more accurately than ever before, which could explore an exciting field for us,” says Yu Fang, MSE, lead author of the new article and a research specialist at the Michigan Neuroscience Institute. “Our findings are not only aimed at directing self-management over sleeping habits, but also at informing institutional scheduling structures.”

Fang is part of the team of the Internal Health Study, led by Srijan Sen, MD, Ph.D., who has been studying the mood and depression risk of first-year medical residents for more than a decade. The study collected an average of two weeks of data before the doctors’ years of practice began, and an average of almost four months of monitoring through their internal year.

For the new article, the team is working with Cathy Goldstein, MD, MS, an associate professor of neurology and physician at the Sleep Disorders Center at Michigan Medicine.

She notes that sleep-enhancing portable devices are now used by millions of people, including the Fitbit devices used in the study, other activity trackers and smart watches.

“These devices allow us to record sleep for long periods of time without effort on behalf of the user,” says Goldstein. “We still have questions about the accuracy of the sleep predictions that consumers’ trackers make, although the initial work indicates similar performance as clinical and actigraphic devices for research cleared by the FDA.”

Sen, who holds the Eisenberg professorship in depression and neuroscience and is a professor of neuroscience and psychiatry, notes that the new findings build on what his team’s work has already shown about the high risk of depression among new doctors, and other underlying factors associated. with an increased risk.

“These findings highlight the consistency of sleep as an underestimated factor in considering depression and well-being,” he says. “The work also highlights the potential of portable devices to understand important constructions relevant to health that we have not been able to study on a large scale before.”

The team notes that the relatively young group of people in the study – with an average age of 27 years, who hold both university and medical degrees – are not representative of the wider population. However, because everyone experiences similar workloads and schedules, it is a good group to test hypotheses. The researchers hope that other groups will study other populations with similar devices and approaches to see if the findings hold about the variation in the sleep scheme. for them.

Fang, for example, notes that the parents of young children can still be an important group to study. “I also wish my 1-year-old could learn from these findings and only wake up every day at 8:21,” she jokes.