Irregular sleep gave scientists alarming signals about mental health

Irregular sleep patterns are associated with more pronounced symptoms of depression, anxiety, and loneliness. This is the conclusion reached by researchers at the University of California, San Francisco and San Diego, after analyzing data from nearly 23,000 users of Oura smart rings. The results of the study were published in the journal Scientific Reports.

The TemPredict study included 22,894 participants from various countries. The average age of respondents was 46 years, with 43.5% being women. Participants wore the Oura ring — a commercial wearable sensor that uses pulse, movement, and finger temperature to determine the moments of falling asleep and waking up. The researchers calculated a sleep regularity index for each participant — a measure of how similar sleep patterns are across different days. A value of 100 indicates a perfect match, while low values indicate a chaotic schedule. Each participant provided data for an average of 154 days of observation, covering approximately seven months.

Among people with severe depression, the average regularity index was 74.93 compared to 83.74 for those with normal scores. For anxiety, the difference was equally notable — 78.94 versus 83.67. Among participants with elevated loneliness, the index was 81.79 compared to 83.75 for those who did not experience loneliness. For every five-point decrease in the index, the odds of falling into a more severe category for depression or anxiety increased.

The link between sleep and mental health has been studied before — more often through sleep duration and quality. The regularity index has been studied little, and loneliness has hardly been examined in this context. The authors note that sleep patterns, unlike sleep duration, can be changed by the individual independently: it is enough to establish consistent wake-up and bedtime schedules. Smart rings and similar devices passively collect data and through apps can suggest ways for users to stabilize their schedules.