Objective: Although the Diagnostic and Statistical Manual of Mental Disorders (DSM), Fourth Edition, acknowledges the existence of dissociative trance and possession disorders, simply named dissociative trance disorder (DTD), it asks for further studies to assess its clinical utility in the DSM-5. To answer this question, we conducted the fi rst review of the medical literature.
Method:The MEDLINE, CINAHL, and PsycINFO databases were searched from 1988 to 2010, seeking case reports of DTD according to the DSM or the International Classifi cation of Diseases defi nitions. For each article, we collected epidemiologic and clinical data, explanatory models used by authors, treatments, and information on the outcome.
Results:We found 28 articles reporting 402 cases of patients with DTD worldwide. The data show an equal proportion of female and male patients, and a predominance of possession (69%), compared with trance (31%). Amnesia is reported by 20% of patients. Conversely, hallucinatory symptoms during possession episodes were found in 56% of patients and thus should feature as an important criterion. Somatic complaints are found in 34% of patients. Multiple explanatory models are simultaneously held and appear to be complementary.
Conclusion:Data strongly suggest the inclusion of DTD in the DSM-5, provided certain adjustments are implemented. DTD is a widespread disorder that can be understood as a global idiom of distress, probably underdiagnosed in Western countries owing to cultural biases, whose incidence could increase given the rising fl ow of migration. Accurate diagnosis and appropriate management should result from a comprehensive evaluation both of sociocultural and of idiosyncratic issues, among which acculturation diffi culties should systematically be considered, especially in cross-cultural settings.Can J Psychiatry. 2011;56(4):235-242.
Clinical Implications• The DSM and the International Classifi cation of Diseases present dissociative trance and possession disorder as a transient involuntary state of dissociation causing distress or impairment.• Although reported worldwide, and possibly owing to various psychosocial stressors, in industrialized societies the disorder may more specifi cally concern people from ethnic minorities for whom acculturation diffi culties may play a key role.• A cross-cultural approach seems necessary for a better understanding of the disorder as well as to increase the validity of diagnosis and effi cacy of management.
Limitations• This review was limited to articles written in English and indexed on major medical databases, thus reducing the number of studies and reported patients.• Owing to cultural biases and misconceptions about altered states of consciousness in Western societies, the disorder may still be underdiagnosed.• Papers showed important discrepancies in both the amount and the precision of data.