Five aspects of the diagnosis and treatment of multiple personality disorder (MPD) were examined. The following five conclusions were made: the contemporary diagnostic criteria are vague and overinclusive; the recent alleged increase in prevalence of the disorder is almost certainly artefactual; legal proceedings involving MPD patients raise disturbing questions about personal responsibility; there is little literature support for the theory that MPD results from childhood trauma; and many of the techniques used to diagnose and treat the condition reinforce its symptoms. A careful revision of diagnostic criteria for the disorder is recommended.