Abstract
The 8-item Youth Self-rated Insomnia Scale (YSIS) was developed to assess insomnia severity in the past month among youths. The YSIS has satisfactory psychometric properties in the general adolescent population. This study examined psychometric properties of the YSIS in a large sample of adolescent psychiatric patients. A total of 536 patients aged 10-19 years were consecutively recruited from the outpatient department of Shandong Mental Health Center between December 2021 and March 2022. Patients completed a structured questionnaire consisting of the YSIS scale and questions about sleep duration, nightmares, psychiatric history, depression, psychiatric and sleep medications, and demographics. Patients were diagnosed following the ICD-10 criteria. Of the participants, the mean age was 15.30 years (SD = 1.95), 61.0% were female, 60.9% were diagnosed with mood disorders, 65.7% were on antidepressants, and 49.0% were on anxiolytics or hypnotics. The mean YSIS score was 22.6 (SD = 8.07). Coefficient omega was 0.84. Exploratory factor analysis revealed one factor and two correlated residuals. The YSIS scores were significantly correlated with depression scores (r = 0.68) and significantly increased with sleep onset latency, short sleep duration, nightmare frequency, and sleep medication use. The YSIS demonstrated satisfactory internal consistency reliability, construct validity, and criteria-related validity in adolescent psychiatric patients. The YSIS appears to be a reliable and valid scale for measuring insomnia severity in adolescent psychiatric patients.