Sleep Duration, Consistency May Be Risk Factors for Adverse Mental Health

A study published in Journal of the National Sleep Foundation has found that changes in sleep consistency and sleep duration, as well as delayed sleep timing were associated with anxiety, depression, substance use, and burnout symptoms during the COVID-19 pandemic.

All participants (N = 4912) were active users of WHOOP, a commercial sleep wearable monitor, and were 18 years and older; they were asked to complete internet-based surveys from June 24-30, 2020. The participants were 70.7% male, and 77.2% were non-Hispanic White adults. Their mean (SD) age was 39.7 (11.24) years.

Variables included in the study were sleep duration in hours in 24-hour intervals, sleep consistency, sleep onset and offset, and wakefulness during time in bed. Naps were included in the 24-hour sleep measures. All scores were on a scale of 0 to 100, with higher scores reflecting lower variability in sleep.

Study intervals were separated into prepandemic (January 1-March 12, 2020) and pandemic (March 13-June 30, 2020). For the sleep analysis, pandemic interval was subdivided into acute pandemic onset (March 13-April 12, 2020) and midpandemic (April 13-June 30, 2020) intervals. Mean sleep duration was categorized as fewer than 6 hours, 6 to 7 hours, or more than 7 hours, with the final measure acting as the optimal sleep duration.

All participants recorded WHOOP data for at least 70% of their nocturnal sleep episodes throughout all 3 study intervals, with 78.3% completing the 4-item Patient Health Questionnaire (PHQ-4) to screen for symptoms of anxiety and depression to include in the mental health subsample.

The mean sleep duration was 0.25 hours (95% CI, 0.237-0.270) longer in the acute pandemic and 0.09 hours (95% CI, 0.076-0.107) longer in the midpandemic compared with the 6.95 hour mean in the prepandemic period.

In addition, sleep consistency increased, compared with the prepandemic, by 3.51 points (95% CI, 3.295-3.728) in the acute pandemic and by 4.06 points (95% CI, 3.856-4.267) in the midpandemic. Wakefulness in bed increased by 0.05 hours (95% CI, 0.031-0.074) in the acute pandemic but did not increase in the midpandemic. Sleep timing shifted to a later time, with mean sleep onset 18.7 minutes later (95% CI, 17.4-20.0) and sleep offset 36.6 minutes later (95% CI, 35.1-38.1); both stayed that way throughout the pandemic.

In the 3845 participants who completed the PHQ-4, 19.6% screened positive for anxiety or depression symptoms, 32.4% screened positive for burnout symptoms, and 22.4% reported new or increased substance use. Participants who slept fewer than 6 hours in both intervals had higher odds of anxiety or depression symptoms (adjusted odds ratio [aOR], 1.75; 95% CI, 1.14-2.69) and burnout symptoms (aOR, 1.57; 95% CI, 1.07-2.29) vs those who slept more than 7 hours.

Participants with sleep consistency below a score of 70 in both intervals had higher odds of all adverse mental and behavioral health symptoms. Odds of new or increased substance use (aOR, 1.46; 95% CI, 1.06-2.01) were higher among participants with sleep consistency scores of 70 to 80 during both intervals. Odds of anxiety and depression symptoms (aOR, 2.07; 95% CI, 1.17-3.67) increased for participants whose sleep consistency decreased from 70 to 80 in the prepandemic period to less than 70 during the pandemic.

There were some limitations to this study. There was a low response rate (14.9%), a lack of prepandemic comparator mental health data, nonrandom recruitment methods, uncertainties about objective measurement of sleep, and potential seasonal influences on sleep and mood.

The researchers concluded that sleep duration and consistency of sleep were potential modifiable risk factors for adverse mental health during stressful life events. They wrote that future studies should explore the directionality and impact of prolonged physiological and behavioral changes, determine predictors of counter-sample sleep patterns, and evaluate public health programs with elements informed by sleep and circadian principles.

Reference

Czeisler ME, Capodilupo ER, Weaver MD, Czeisler CA, Howard ME, Rajaratnam SM. Prior sleep-wake behaviors are associated with mental health outcomes during the COVID-19 pandemic among adult users of a wearable device in the United States. Sleep Health. Published online April 20, 2022. doi:10.1016/j.sleh.2022.03.001