OBJECTIVE: To empirically investigate whether or not symptoms of posttraumatic stress disorder (PTSD) are essential for transferring the negative effects of trauma on the severity of severe mental illness (SMI) as recently suggested by an interactive model. METHODS: About 122 inpatients with either schizophrenia or major affective disorder were administered the Posttraumatic Diagnostic Scale, the Symptom Checklist and the Toronto Alexithymia Scale. RESULTS: At least one trauma was reported by 83 participants (68%) and 28 patients (23%) reported symptoms of current PTSD. Those SMI subjects with current PTSD symptoms had significantly more psychopathological distress and alexithymic features than those with a trauma exposure but without PTSD symptoms and those patients without any traumatic experiences. DISCUSSION: In line with prior research, our data indicate that patients with SMI have frequently been exposed to traumatic events and that a third suffers from current posttraumatic stress symptoms. Despite some methodological limitations our findings support the interactive model, which posits that a comorbid PTSD increases the symptom severity of SMI. More attention should be directed at assessing trauma and PTSD in SMI patients and at developing therapeutic interventions.
