Controversy surrounds the diagnoses of “dissociative amnesia” and “dissociative identity disorder” (also known as “multiple personality disorder”). The American Psychiatric Association’s DSM-IV (1) recognizes both as official diagnostic categories, a fact sometimes cited as evidence of general acceptance (2). By contrast, the World Health Organization’s International Classification of Diseases, 10th Revision (ICD-10) (3,4) is more skeptical, classifying dissociative disorders as conversion disorders and suggesting that dissociative identity disorder may be “a culture-specific or even iatrogenic condition” (3, p 15).

Manuscript received September 2000 and accepted March 2001.
Previously presented in part at the Annual Meeting of the Canadian Psychiatric Association; September 1999; Toronto; and the Annual Meeting of the American Psychiatric Association; May 2000; Chicago.
¹Associate Chief, Child and Adolescent Psychiatry Research, Biological Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts; Clinical Fellow in Psychiatry, Harvard Medical School, Boston, Massachusetts.
²Associate Chief, Biological Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts; Associate Professor of Psychiatry, Harvard Medical School, Boston, Massachusetts.
³Research Assistant, Biological Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts.
⁴Chief, Biological Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts; Professor of Psychiatry, Harvard Medical School, Boston, Massachusetts.
Address for correspondence: Dr J Lalonde, Biological Psychiatry Laboratory, McLean Hospital, 115 Mill Street, Belmont, MA  02478
e-mail: biopsych@mclean.org

Even within the US, where the DSM-IV is widely used, a survey of psychiatrists found little consensus regarding these diagnoses, with only about one-third of respondents answering that dissociative amnesia and dissciative identity disorder should be included withouth reservations in the DSM-IV (5). Fewer than one-quarter felt that strong scientific evidence supported their validity.

To expand our study, we surveyed a representative national sample of Canadian psychiatrists. We sought to test 3 hypotheses: 1) that French-speaking Canadian psychiatrists are less accepting of dissociative disorder diagnoses than are their English-speaking counterparts, given the dearth of literature in French supporting these entities (6); 2) that Canadian psychiatrists as a whole are less accepting than are American psychiatrists, given evidence that the British Commonwealth literature has generally been more critical of the concept of dissociative disorders (7); and 3) that, as in the US, psychodynamically-oriented Canadian psychiatrists are more accepting of dissociative disorders than are biologically-oriented ones.

Method

We identified Canadian psychiatrists by consulting the Canadian Medical Directory (8), which lists certified psychiatrists alphabetically by town, borough, and city within each province.