Role of Posttraumatic Stress Disorder Symptoms in Life Adaptation of Toxic Humidifier Disinfectant Survivors: A Multi-Group Analysis

<b>Background:</b> The Republic of Korean humidifier disinfectant disaster, involving toxic chemical exposure, constitutes a major social disaster causing severe trauma. While physical and psychological difficulties are documented, this study investigated the relationship between posttraumatic stress disorder (PTSD) symptoms and survivors' daily life adaptation across children, adolescents, and adults, examining PTSD's mediating role. <b>Methods:</b> The sample included 834 participants (417 exposed survivors and 417 unaffected individuals), divided into three age groups. PTSD symptoms and life adaptation were measured via self-reports. Multigroup Structural Equation Modeling (SEM) was utilized to test the indirect associations among exposure, PTSD symptoms, and life adaptation, and to examine age-group comparisons. <b>Results:</b> Survivors in all age groups reported higher PTSD symptoms and lower adaptive functioning compared to unaffected individuals, with the largest PTSD mean difference found in children and adults. Multigroup SEM confirmed that exposure positively impacted PTSD symptoms, and PTSD symptoms negatively impacted life adaptation across all ages. PTSD symptoms significantly mediated the exposure-life adaptation link in all groups. Critically, the direct effect of exposure on life adaptation was significant only in adults, indicating a full mediation via PTSD symptoms in children and adolescents. <b>Conclusions:</b> Exposure to toxic humidifier disinfectants is linked to life adaptation difficulties through elevated PTSD symptoms. These findings emphasize addressing trauma-related symptoms and suggest the utility of developmentally sensitive psychological interventions. Limitations include reliance on self- and parent-reported measures rather than clinical diagnoses, and the lack of control for external contextual factors (e.g., policy changes, media exposure).