Prevalence, severity, and correlates of post-traumatic stress disorder in 205 outpatients with schizophrenia: results from a cross-sectional, observational study assessing diagnoses via the Mini-International Neuropsychiatric Interview

Abstract Objectives To report prevalence, severity and clinical and inflammatory correlates of Post-Traumatic Stress Disorder (PTSD) in patients with schizophrenia. Methods This cross-sectional, observational study included adult outpatients with schizophrenia/schizophreniform disorder. Assessments included the Mini-International Neuropsychiatric Interview (MINI), Post-traumatic Stress Disorder Symptom Severity Scale-Revised, Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale for Schizophrenia (CDSS), Global Assessment of Functioning Scale (GAF), and inflammatory markers (neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio, systemic immune-inflammation index: platelets × neutrophils)/lymphocytes). Analyses compared patients with (SCZ + PTSD) versus without PTSD (SCZ-PTSD) across demographic, clinical, and biological variables. Results SCZ + PTSD had higher PANSS-total scores (80.7 ± 19.5 vs. 71.6 ± 17.1; p = 0.003), more comorbid depression (73.8% vs. 23.3%; p < .001), higher CDSS scores (9.5 ± 4.9 vs. 3.2 ± 4.1; p < .001), more frequent suicide attempts (40.5% vs. 23.0%; p = 0.05), lower GAF scores (39.8 ± 12.3 vs. 49.6 ± 12.3; p < .001) and more medical comorbidities (51.1% vs. 42.8%; p = .014). Inflammatory markers did not differ significantly between groups. Logistic regression analyses identified higher CDSS scores (OR = 1.25, 95% CI [1.15, 1.36], p < .001) and lower GAF scores (OR = 0.96, 95% CI [0.93, 0.99], p = .007) as significant correlates of PTSD (r 2 = 0.22). Conclusions PTSD is common and clinically relevant in people with schizophrenia, underscoring the need for routine screening and targeted interventions in this population.