An irregular sleep schedule may lead to more severe symptoms of anxiety, depression and loneliness. A large study from UC San Francisco (UCSF) and UC San Diego (UCSD) focused on sleep regularity using months of data collected from wearables. Older research mostly looked at duration and quality of sleep rather than how consistently people went to bed and woke up at the same time.
“Regular sleep and wake times help keep circadian rhythms aligned,” said senior author Ashley Mason of UCSF. “Irregular sleep-wake timing may weaken circadian alignment, which is associated with depression and other mental health disorders.”
On average, participants contributed 153 days of sleep data, giving researchers a long stretch of time to see patterns. Unlike shorter studies from the past, they saw a much clearer link between sleep regularity and mental health. Mental health was assessed in monthly self-reported surveys. Less regular sleep correlated with worse depression and anxiety.
“If you have an irregular sleep schedule, your social interactions are thrown off, your eating is thrown off, your exercise is thrown off,” said Dr. Rafael Pelayo, a Stanford sleep specialist. “The point being that having an irregular sleep schedule messes you up.”
People were scored for their sleep regularity on a scale from zero to 100. The higher the number, the more consistent their sleeping patterns were. The people who were least depressed had an average score of 84. People with severe symptoms of depression had an average score of 75. People with normal levels of anxiety had a score of 84. People with severe anxiety had a score of 79. People who reported being lonelier also had a lower sleep regularity score.
“You want to get as regular as you can with your sleep,” said Prof. Mason. “That’s the takeaway.”
People are often obsessed with getting their eight hours of sleep, not worrying about when that happens. This study suggests consistency is more important for mental health than length.
“Stop obsessing over eight hours,” said Mason. “It all comes back to consistency.”
