Prevalence of dissociative disorders in psychiatric outpatients

The purpose of the study was to assess the prevalence of DSM-IV dissociative disorders in an inner-city outpatient psychiatric population.

Subjects were 231 consecutive admissions (84 men and 147 women, mean age=37 years) to an inner-city, hospital-based outpatient psychiatric clinic. The subjects completed self-report measures of dissociation (Dissociative Experiences Scale) and trauma history (Traumatic Experiences Questionnaire). Eighty-two patients (35%) completed a structured interview for dissociative disorders (Dissociative Disorders Interview Schedule).

The 82 patients who were interviewed did not differ significantly on any demographic measure or on the self-report measures of trauma and dissociation from the 149 patients who were not interviewed. Twenty-four (29%) of the 82 interviewed patients received a diagnosis of a dissociative disorder. Dissociative identity disorder was diagnosed in five (6%) patients. Compared to the patients without a dissociative disorder diagnosis, patients with a dissociative disorder were significantly more likely to report childhood physical abuse (71% versus 27%) and childhood sexual abuse (74% versus 29%), but the two groups did not differ significantly on any demographic measure, including gender. Chart review revealed that only four (5%) patients in whom a dissociative disorder was identified during the study had previously received a dissociative disorder diagnosis.

Dissociative disorders were highly prevalent in this clinical population and typically had not been previously diagnosed clinically. The high prevalence of dissociative disorders found in this study may be related to methodological factors (all patients were offered an interview rather than only those who had scored high on a screening self-report measure) and epidemiological factors (extremely high prevalence rates for childhood physical and sexual abuse were present in the overall study population).