Trauma Exposure and Co‐occurring ICD‐11 Post‐traumatic Stress Disorder and Complex Post‐traumatic Stress Disorder in Adults with Lived Experience of Psychiatric Disorder

Objective To establish factors associated with ICD-11 post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD) in a large sample of adults with lived experience of psychiatric disorder and examine the psychiatric burden associated with the two disorders. Methods One thousand three hundred and five adults were recruited from the National Centre for Mental Health (NCMH) cohort. ICD-11 PTSD/CPTSD were assessed with the International Trauma Questionnaire (ITQ). Binary logistic regression was used to determine factors associated with both PTSD and CPTSD. One-way between-groups analysis of variance was conducted to examine the burden associated with the two disorders in terms of symptoms of anxiety, depression, and psychological wellbeing. For post-hoc pairwise comparisons, the Tukey HSD test was used, and the magnitude of between-group differences assessed using Cohen's d. Results Probable ICD-11 CPTSD was more common than PTSD within the sample (PTSD 2.68%; CPTSD 12.72%). We found evidence that PTSD was associated with interpersonal trauma and household income under 20,000 pound a year. CPTSD was also associated with interpersonal trauma, higher rates of personality disorder, and lower rates of bipolar disorder. Those with probable-CPTSD had higher levels of current anxiety and depressive symptoms and lower psychological wellbeing in comparison to those with probable-PTSD and those with neither disorder. Conclusions CPTSD was more prevalent than PTSD in our sample of people with lived experience of psychiatric disorder. Our findings indicate a need for routine screening for trauma histories and PTSD/CPTSD in clinical settings and a greater focus on the need for interventions to treat CPTSD.