Nightly Heart Rate Variability as a Biomarker of Mental Health Changes in College Students

The transition to college represents a great change for adolescents, with new challenges living independently and increased academic pressure and subsequent increases in anxiety, depression, and stress. Wearable sensors offer an opportunity to passively and continuously collect physiological quantities that underly these mental health changes. In this study we analyze smart-ring (Oura) heart rate variability (HRV) data from 108 students continuously for a period of 6 months during their first year of college. Students self-reported their mental health diagnoses upon college entry and completed surveys (DASS-21) about their total anxiety, depression and stress symptoms every two weeks. Linear mixed models reveal that increases in mental health symptoms across weeks was associated with decreases in HRV (p = 0.01), consistent with prior research. Interestingly, there was a significant interaction driven mainly by females such that students with an anxiety disorder showed the opposite relationship between mental health symptom changes and HRV (p < 0.05). For females with an anxiety disorder, increases in mental health symptoms were associated with increases in HRV, possibly indicating different coping strategies. In conclusion, HRV measured via smart-rings is a promising digital biomarker for tracking fluctuations in mental health symptoms.