Dysregulated sleep-wake cycles in young people are associated with emerging stages of major mental disorders

Aim: To determine if disturbed sleep-wake cycle patterns in young people with evolving mental disorder are associated with stages of illness. Methods: The sleep-wake cycle was monitored using actigraphy across 4 to 22 days. Participants (21 healthy controls and 154 persons seeking help for mental health problems) were aged between 12 and 30 years. Those persons seeking mental health care were categorized as having mild symptoms (stage 1a), an 'attenuated syndrome' (stage 1b) or an 'established mental disorder' (stage 2+). Results: The proportions of individuals with a delayed weekdays sleep schedule increased progressively across illness stages: 9.5% of controls, 11.1% of stage 1a, 25.6% of stage 1b, and 50.0% of stage 2+ (χ² (3 d.f.)=18.4, P<0.001). A similar pattern was found for weekends (χ² (3 d.f.)=7.6, P=0.048). Compared with controls, stage 1b participants had later sleep onset on weekends (P=0.015), and participants at stages 1b and 2+ had later sleep offset on both weekdays and weekends (P<0.020). Compared with controls, all participants with mental disorders had more wake after sleep onset (P<0.029) and those at stages 1a and 2+ had lower sleep efficiency (P<0.040). Older age, medicated status and later weekdays sleep offset were found to be the three strongest correlates of later versus earlier clinical stages. Conclusions: In relation to clinical staging of common mental disorders in young people, the extent of delayed sleep phase is associated with more severe or persistent phases of illness.