Psychiatric comorbidity predicts sleep disturbances among adolescent earthquake survivors: a 10-year cohort study

Objective: To examine the prevalence of sleep disturbances 10 years after Wenchuan earthquake, and to explore whether comorbid post-traumatic stress disorder (PTSD) and depressive symptoms could predict sleep disturbances and whether such effects were modified by gender. Methods: Participants were 1357 adolescents in the Wenchuan Earthquake Adolescent Health Cohort Study (WEAHC). 799 of the participants completed the followed-up survey 10 years after the earthquake. At 12-month post-earthquake (T12m), a battery of standardized measures were used to assess individual earthquake exposure, sleep disturbances (insomnia symptoms and poor sleep quality), PTSD, and depressive symptoms. At 10 years post-earthquake (T10y), those survivors reported their sleep disturbances via an online survey. Data were analyzed using binary logistic regression. Results: The prevalence of insomnia (14.3%) and of poor sleep quality (19.8%) at T10y decreased when compared with it at T12m. After controlling for covariates, it is revealed that depression-only and comorbidity groups at T12m predicted sleep disturbances at T10y among the whole sample and males. As for females, who have depression-only and comorbidity were more likely to develop insomnia symptoms but not poor sleep quality. Conclusions: Sleep disturbances remained highly prevalent among survivors even 10 years after the earthquake. Depression-only and comorbidity groups were related to higher risks of sleep disturbances, especially for males. Assessments and interventions targeting both depressive symptoms and comorbid PTSD to reduce sleep disturbances after a deadly disaster are warranted.