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

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.

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 (T_12m), 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 (T_10y), those survivors reported their sleep disturbances via an online survey. Data were analyzed using binary logistic regression.

The prevalence of insomnia (14.3%) and of poor sleep quality (19.8%) at T_10y decreased when compared with it at T_12m. After controlling for covariates, it is revealed that depression-only and comorbidity groups at T_12m predicted sleep disturbances at T_10y 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.

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.