Identifying Candidate Mechanisms of Comorbidity in Disordered Eating and Posttraumatic Stress Disorder Symptoms Among US Veterans: A Network Analytic Approach

Objective: Comorbidity between posttraumatic stress disorder (PTSD) and disordered eating (DE) symptoms is common, reflecting a possible reciprocal relationship between these disorders. Network analysis may reveal candidate mechanisms underlying their comorbidity and highlight important treatment targets. Method: Two national samples of U.S. veterans endorsing trauma exposure self-reported PTSD and DE symptoms. The discovery sample included veterans from all service eras (n = 434). The validation sample included recently separated post-9/11 veterans (n = 507). We fit graphical lasso models to evaluate the network structure of PTSD factors based on the seven-factor "hybrid" model and DE symptoms within each sample. We used strength scores to identify the most central symptoms within the networks and identified bridge symptoms connecting PTSD and DE features. We tested for network invariance between self-identified men and women within each sample and across the studies. Results: PTSD and DE symptoms clustered as expected within networks for each sample. The strongest nodes in the networks included both PTSD and DE features. The strongest bridge symptoms in both studies included overevaluation of shape and weight, negative affect, and avoidance. Networks were invariant across men and women in each sample and largely invariant across samples. Conclusions: Cross-sectional network models of PTSD and DE symptoms largely replicated across national samples of U.S. veterans and between men and women within samples. Cognitive features of both disorders, along with avoidance, may partially underlie comorbidity and represent potential treatment targets. Clinical Impact Statement Disordered eating and posttraumatic stress disorder symptoms often co-occur. This study looked at what symptoms underlie this comorbidity in two samples of U.S. veterans. The results suggested that cognitive symptoms of these conditions, such as negative trauma-related affect and overevaluation of one's shape and weight, may promote this comorbidity. The findings were similar across self-identified men and women. It may be particularly important to target these cognitive symptoms when treating patients who present with comorbid disordered eating-posttraumatic stress disorder symptoms.