Oura Ring study finds sleep and HRV changes linked to depression and anxiety

This is pretty interesting. Researchers looked at Oura Ring data and found that people reporting more serious depression and anxiety symptoms tended to sleep worse, have lower HRV, a higher sleeping heart rate and move less during the day.

The study, published in BMC Medicine, analysed 1,290 people from the Northern Finland Birth Cohort. Participants were aged 33 to 35 and were asked to wear an Oura Ring for two weeks while also completing established questionnaires covering anxiety and depression symptoms.

The pattern shows up in several metrics

People reporting moderate-to-severe anxiety tended to spend less of the night in REM and deep sleep and more time in light sleep. Similar differences appeared among participants whose questionnaire results indicated depression and anxiety symptoms.

And it was not just sleep stages. Those groups also tended to have a higher heart rate during sleep, lower nighttime HRV and lower levels of physical activity during the day.

None of those findings on their own are particularly surprising. Poor sleep, reduced activity and changes in autonomic nervous system activity have all been associated with mental health before. What makes this study more interesting is that all of these signals were picked up passively by an ordinary consumer smart ring while people went about their normal lives.

HRV is particularly worth watching here. We have written before about how wearables use HRV to track recovery and stress, and lower readings can show that the body is dealing with some kind of additional load. The problem is that HRV cannot tell you what that load actually is.

Alcohol, illness, poor sleep, training, stress and plenty of other things can all move the number. So seeing low HRV on an Oura Ring obviously does not mean someone has depression or anxiety.

The study becomes more useful when those signals are looked at together. Lower HRV combined with higher sleeping heart rate, less deep and REM sleep and reduced daytime movement starts to create a broader physiological and behavioural pattern rather than relying on any single measurement.

This was not Oura’s latest hardware

The researchers actually used the second-generation Oura Ring. Which makes the results a little more interesting. The study was not relying on some new sensor or experimental mental health feature. It was using fairly basic metrics that smart rings and watches have already been collecting for years.

Participants also did not receive feedback from the ring during the study, so their behaviour was not being nudged by readiness scores or recommendations in the Oura app. The researchers were essentially looking at the raw pattern left behind by sleep, nighttime heart rate, HRV and movement.

There are still some big limitations. This was a cross-sectional study, so it shows an association at one point in time rather than demonstrating that these wearable changes predict worsening mental health. The participants were also all around the same age and came from the same Finnish birth cohort.