Association of Sleep Quality, Sleep Disturbances, and Chronotype with Post-Traumatic Stress Disorder in Earthquake-Exposed Adolescents

Background/Objectives: Post-traumatic stress disorder (PTSD) is a common psychiatric consequence of trauma, and adolescents may be particularly vulnerable after large-scale disasters. Sleep disturbances and circadian preference may play a role in PTSD symptomatology. This study aimed to investigate the associations between PTSD, sleep quality, sleep problems, and chronotype in adolescents exposed to an earthquake. Methods: This cross-sectional study included 201 adolescents aged 12–18 years: 92 diagnosed with PTSD and 109 earthquake-exposed controls without a DSM-5 psychiatric disorder. Participants completed the Children’s Posttraumatic Stress Reaction Index (CPTS-RI), Pittsburgh Sleep Quality Index (PSQI), Children’s Sleep Habits Questionnaire (CSHQ), and Children’s Chronotype Questionnaire (CCTQ). Group differences, correlation analyses, and binary logistic regression analyses were performed. Results: Adolescents with PTSD had significantly higher CPTS-RI, PSQI, CSHQ, and CCTQ scores compared with controls (all p < 0.001), indicating poorer sleep quality, more sleep problems, and a greater tendency toward eveningness. PTSD severity was positively correlated with sleep problems, impaired sleep quality, and eveningness. In logistic regression analysis, poor sleep quality (p < 0.001) and clinically significant sleep problems (p = 0.011) were independently associated with PTSD, whereas chronotype was not. Conclusions: Sleep disturbances are more strongly associated with PTSD than chronotype in earthquake-exposed adolescents. Assessment and treatment of sleep problems may represent an important therapeutic target following large-scale trauma.