The reciprocal relationship between posttraumatic stress disorder symptoms and alcohol use in a large multisite longitudinal sample stratified by sex: A random-intercept cross-lagged panel model

Background and aims: Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) often co-occur. There are a lack of longitudinal studies measuring the naturalistic development of PTSD and alcohol use problems in individuals with recent trauma exposure. This study aimed to compare the temporal relationships between posttraumatic stress symptoms and alcohol use over six months following trauma exposure in males and females. Design: Large-scale longitudinal observational emergency department (ED)-based study of individuals with recent trauma exposure. Setting: Twenty-nine EDs across the United States. Participants: Individuals with recent trauma exposure (n=2942, 62% female) were recruited from EDs within 72 hours of trauma exposure between 2017 to 2021. Measurements: PTSD symptoms, measured via the PTSD Checklist for the DSM-5, and alcohol use was measured via the PhenX toolkit, were assessed at five time points: ED visit, 2 weeks, 8 weeks, 3 months, and 6 months following trauma.Findings: PTSD symptoms predicted lower future alcohol use between the pre-trauma to 2-week timepoints (b=-0.08, p=0.01) and higher use between the 3 to 6-month timepoints (b=0.06, p=0.01). There were no timepoints in which alcohol use predicted future PTSD symptoms. When stratifying by sex, male participants showed reciprocal associations, with alcohol use early after trauma predicting PTSD symptoms between 2 to 8 weeks (b=0.08, p=0.01), while PTSD symptoms predicted alcohol use between the 3 to 6-month timepoints (b=0.10, p=0.01). Female participants showed a different reciprocal pattern, with pre-trauma PTSD symptoms predicting lower alcohol use 2 weeks post-trauma (b=-0.08, p=0.04), while alcohol use subsequently predicted greater PTSD symptoms from 8 weeks to 3 months (b=0.04, p=0.04).Conclusions: Males and females exhibit complex temporal development patterns of PTSD symptoms and alcohol use that align with the mutual maintenance hypothesis in men but the susceptibility hypothesis in females. These patterns are masked in analyses that do not stratify by sex.