Digital Insomnia and Circadian Therapy for Reducing Depression Symptoms in College Students

Depression is a leading cause of global disease burden, poor quality of life, disability and suicide, and commonly occurs in adolescence and early adulthood. Insomnia and circadian factors were regarded as potential targets for preventing worsening of depressive symptoms. Additionally, digital insomnia treatment reduces depressive symptoms but is insufficient for individuals with an evening chronotype. Circadian intervention is an adjunctive treatment for sleep disturbance and depression, but is often overlooked. In this study, we aim to evaluate the effect of guided digital insomnia and circadian intervention (dCBT-I + dCI) in reducing depressive symptoms in college students with insomnia and an evening chronotype compared with digital insomnia intervention alone (dCBT-I) and a health education group (dHE). We also aim to develop and evaluate multimodal prediction models to identify individuals who are more or less likely to respond to the interventions, using clinical, behavioral, circadian, and digital engagement data.

Inclusion Criteria: * Youths aged between 18-24 years old. * Insomnia disorders as determined by DSM-5 criteria with a predominant complaint of difficulty initiating sleep. * Presence of an evening chronotype according to the score on the Horne-Östberg Morning-Eveningness Questionnaire (MEQ) and having a late bedtime of 12:00 am/midnight or later for at least 3 nights per week in the last 3 months. * Presented with at least subclinical depressive symptoms as determined by Patient Health Questionnaire-9 ≥ 10. * Accessibility to a smartphone. Exclusion Criteria: * Having a diagnosed sleep disorder that may potentially contribute to the disruption of sleep quantity and quality other than insomnia and delayed sleep phase syndrome, as ascertained by Structured Diagnostic Interview for Sleep patterns and Disorders (DISP), such as restless leg syndrome and OSA, and narcolepsy. * Diagnosed with neuropsychiatric disorders such as major depressive disorder, anxiety disorders, bipolar affective disorders, schizophrenia, moderate or above suicidality. * Concurrent, regular use of medications known to affect sleep continuity and quality, including both Western medications (e.g. hypnotics, steroids, antidepressants, antihistamines) and over-the-counter medications (e.g. melatonin). * Participate in other psychotherapy (e.g., CBT, mindfulness) currently or in the past three months.