Dissociation as transdiagnostic mediator between trauma exposure and the post-traumatic stress disorder-psychosis...

Trauma exposure is associated with dissociation, post-traumatic stress disorder (PTSD), and psychosis; however, less is known about whether dissociation is a transdiagnostic mediator between trauma exposure and the PTSD-psychosis symptom spectrum. Hence, we conducted a meta-analysis to elucidate the associations among trauma exposure, dissociation, PTSD symptoms, and psychotic symptoms. A total of 311 articles with 94,454 individuals were coded and a two-stage meta-analytical structural equation model was used to investigate the indirect effect of trauma exposure on PTSD symptoms and psychotic symptoms through dissociation. Subgroup analyses investigated the heterogeneity in indirect effects due to dissociation type (i.e., general dissociation versus traumatic dissociation), sample type, study design, study quality, and geographical differences. The indirect effect from trauma exposure to PTSD symptoms via dissociation was significant (β = 0.15, 95 % CI [0.13, 0.17]). The indirect effect from trauma exposure to psychotic symptoms via dissociation was significant (β = 0.14, 95 % CI [0.12, 0.17]). There was no statistical difference between both indirect effects. Subgroup analyses revealed larger indirect effects for traumatic dissociation, clinical samples, non-Western countries, and poor quality studies. The present meta-analytic results indicate that dissociation is a transdiagnostic mediator in the relationship between trauma exposure and the PTSD-psychosis symptom spectrum. Traumatic dissociation and clinical samples were associated with larger indirect effects. These findings inform clinical practice and future transdiagnostic research on PTSD and psychosis.