Letters to the Editor
Re: Canadian and American Psychiatrists’ Attitudes Toward Dissociative Disorder Diagnoses
The data in the recent article by Lalonde, Hudson, Gigante, and Pope Jr (1) do not support their conclusion that there is little consensus among psychiatrists on the diagnostic status or scientific validity of dissociative amnesia or dissociative identity disorder (p 411).With regard to including these disorders in revised editions of the DSM-IV, if one uses raw percentages of respondents, instead of the authors weighted percentages, 85% of psychiatrist respondents in their survey stated that dissociative amnesia should be included, and 74% stated that dissociative identity disorder should be included. If one removes respondents who stated that they had no opinion, the figures are 92% and 87%, respectively. Similarly, figures for partial or strong evidence of scientific validity are 67% and 65%, respectively, but if one removes respondents with no opinion, they are 73% and 70%.
Given that most respondents probably have little knowledge of the literature on the reliability and validity of the dissociative disorders, the survey results appear to me to represent a consensus for including dissociative amnesia and dissociative identity disorder in future editions of the DSM-IV. In politics, such numbers would be referred to as a mandate, a landslide victory, or an endorsement. (Since an opinion survey is basically a vote, and given the fact that psychiatry is far from an exact science, vocabulary from politics may be suitable for summarizing the authors data.)
Inclusion with reservation was a response option in the authors questionnaire. Responding to the survey, I would endorse inclusion with reservation if reservation meant that consideration should be given to issues such as monothetic vs polythetic criteria, better use of criteria sets, updating of the text to incorporate new research data, the need to include dissociative identity disorder and certain subtypes of dissociative disorder not otherwise specified in a common dissociative taxon, and so on.
If there were a similar survey about the inclusion of schizophrenia in future editions of DSM-IV, I would respond only with reservations where reservations meant that greater emphasis on negative symptoms should be considered. I have reservations about the diagnostic specificity of positive symptoms of schizophreniaand about its syndromal validityand I consider these concerns of mine to be normative.
With regard to the scientific validity of the dissociative disorders, it is unclear what partial validity means as a response option. If partial validity means that a sufficient quantity of definitive reliability data from various cultures using various measures have not yet been published, then I would endorse the partial validity option. However, I would still maintain that both dissociative amnesia and dissociative identity disorder have sufficient data on their reliability and validity for inclusion in DSM-IV, a conclusion endorsed by the American Psychiatric Association.
1. Lalonde JK, Hudson JI, Gigante RA, Pope HG. Canadian and American psychiatrists attitudes toward dissociative disorder diagnoses. Can J Psychiatry 2001;46:40712.
Colin A Ross, MD
The Authors Reply
To put the most positive spin on the opinions of Canadian psychiatrists, Dr Ross groups together psychiatrists who feel that dissociative disorders should be included in future editions of DSM-IV and those who feel that these diagnoses should be included only with reservations. However, it is inappropriate to lump these 2 groups together. This fact becomes clearer upon examination of the full text of the reservations option on the questionnaire: should be included only with reservations (for example, only as a proposed diagnosis). This was reported in our article on the American responses (1), but not in our article on the Canadian results (2). Proposed diagnoses are not listed in the text of DSM-IV as official diagnoses but are relegated to Appendix B, where the introduction states that research will help to determine the possible utility of these proposed categories. Clearly, psychiatrists willing to accept only the tentative status of a proposed diagnosis would feel misused if they were claimed to be part of a mandate or a landslide victory. Using our unweighted percentages and excluding individuals expressing no opinion represent equally invalid methods of inflating the apparent acceptance of dissociative disorders and do not make a large numerical difference, in any case.
Simply stated, one may choose to interpret our findings as showing that
the glass is either half-full or half-empty (as we have noted before ),
but by any standard one cannot claim that there is any consensus one way
or the other on the diagnostic status or scientific validity of the dissociative
2. Pope HG Jr, Oliva PS, Hudson JI, Bodkin JA, Gruber AJ. Attitudes towards DSM-IV dissociative disorders diagnoses among board-certified American psychiatrists. Am J Psychiatry 1999;156:3213.
3. Pope HG Jr, Oliva PS, Hudson JI, Bodkin JA, Gruber
AJ. Psychiatrists attitudes towards dissociative disorders. Am J
Justine K Lalonde, MD