Posttraumatic stress disorder in a Swiss offender population

Various studies have repeatedly shown an increased prevalence for Posttraumatic Stress Disorder (PTSD) in delinquents when compared with the general population. Lifetime prevalence varies between 33% and 36%, and point prevalence between 17% and 21%. The aim of this study was to examine whether these findings are applicable to offenders detained in Switzerland.

The sample consisted of 86 offenders. In order to control for over-reporting of traumatic life events three sub-samples (remand, sentenced/inpatient and sentenced/outpatient) administered by the Office of Corrections of the Canton of Zurich were examined. PTSD was diagnosed using the Posttraumatic Diagnostic Scale (PDS), a self-rating instrument for diagnosing PTSD according to the Diagnostic and Statistical Manual of Mental Disorders, Version IV (DSM-IV).

Point prevalence of PTSD was conservatively estimated at 27%. The three sub-samples did not differ in the prevalence of PTSD when adjusted for potential demographic differences. Seventy-five percent of the subjects had experienced at least one traumatic event that matched the criteria for a traumatic event according to the DSMIV. The Median number of traumatising life events according to the PDS was four in the examined sample.

In this sample of male prisoners in Switzerland the prevalence of current PTSD was comparable to other international studies. The limitations and implications of these findings were discussed.