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 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.