The utility of wearable headband electroencephalography and pulse photoplethysmography to assess cortical hyperarousal in individuals with stress-related mental disorders

Study ObjectivesSeveral stress-related mental disorders are characterized by disturbed sleep, but objective sleep biomarkers are not routinely examined in psychiatric patients. We examined the use of wearable-based sleep biomarkers in a psychiatric sample with headband electroencephalography (EEG) including pulse photoplethysmography (PPG), with an additional focus on microstructural elements as especially the shift from low to high frequencies appears relevant for several stress-related mental disorders (cortical hyperarousal). MethodsWe acquired 483 nights and could analyze 372 nights of sufficient quality from 83 healthy participants and those with a confirmed stress-related mental disorder (anxiety-affective spectrum). We analyzed the data with respect to macrostructural and microstructural characteristics according to the newly described spectral slope fitting over the whole frequency spectrum. ResultsThe headbands were accepted well by patients and the data quality was sufficient for most nights. The macrostructural analyses revealed trends for significance regarding sleep continuity but not sleep depth variables. The spectral analyses yielded no between-group differences except for a group x age interaction, with the normal age-related decline in the low versus high frequency power ratio flattening in the patient group. PPG analyses showed that the mean heart rate was higher in the patient group in pre-sleep epochs, a difference that reduced during sleep and dissipated at wakefulness. ConclusionsWearable devices that record EEG and/or PPG could be used over multiple nights to assess relevant markers such as sleep fragmentation, cortical hyperarousal, and sympathetic drive throughout the sleep-wake cycle in patients with stress-related mental disorders.