Historical reliability: a key to differentiating populations among patients presenting signs of multiple personality disorder.

The clinical value of inconsistencies in the historical data of patients presenting with signs of multiple personality disorder was assessed. Three major inconsistencies in historical data were identified in 23 patients who were admitted to a Dissociative Disorders Program with a diagnosis of Multiple Personality Disorder. This group showed psychological disturbance that was quite different from 23 patients with a similar discharge diagnosis but who did not exhibit inconsistencies in history. The former group reported less psychological disturbance and fewer dissociative experiences. Patients who are less credible by virtue of inconsistencies in their historical reports may belong to a different diagnostic group. The findings point to the need to chart history carefully in authenticating genuine cases.