Interplay Between Childhood Maltreatment, Subclinical Post-Traumatic Stress Symptoms, and IQ: Findings From the EU-GEI Multicentre Case–Control Study

Introduction: Evidence suggests that childhood maltreatment affects cognitive performance in both patients with psychosis and community controls. However, the interplay between childhood maltreatment, post-traumatic stress symptoms (PTSS), and intelligence has not been investigated. This study investigated the relationship between childhood maltreatment, subclinical PTSS, and intelligence among patients with first-episode psychosis (FEP) and community controls. Methods: Patients with FEP (N = 602) and controls (N = 853) from the EU-GEI study were assessed for childhood maltreatment, PTSS, and intelligence quotient (IQ). Results: PTSS were associated with lower IQ among community controls but not among patients with FEP. In the FEP group, an interaction (p = 0.044) between PTSS and childhood maltreatment on IQ was found, such that the association between PTSS and lower IQ was only present among those exposed to childhood maltreatment. No interaction was evident in controls (p = 0.826). Conclusions: The findings suggest the relevance of cognitive rehabilitation for FEP patients with childhood maltreatment and PTSS.