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Relevance of the 5-HTTLPR Polymorphism and Childhood Abuse to Increased Psychiatric Comorbidity in Women With Bulimia-Spectrum Disorders

Jodie Richardson, B.Sc.; Howard Steiger, Ph.D.; Norbert Schmitz, Ph.D.; Ridha Joober, M.D., Ph.D.; Kenneth R. Bruce, Ph.D.; Mimi Israel, M.D.; Lise Gauvin, Ph.D.; Annelie S. Anestin, B.A.; Cathy Dandurand, B.A.; Heidi Howard, Ph.D.; and Rosherrie de Guzman, B.Sc.

Objective: Individuals with bulimia nervosa have been shown to display heterogeneous profiles of comorbid psychiatric disturbance, possibly due to varying degrees of genetic and environmental vulnerability. Using information about comorbid psychiatric disturbances, we developed an empirically based classification of individuals with bulimia-spectrum disorders, and then explored whether or not the resulting phenotypes corresponded to variations in the serotonin transporter promoter polymorphism (5-HTTLPR) and exposure to childhood abuse.

Method: Eighty-nine women aged 17 to 49 years with DSM-IV bulimia-spectrum disorders completed questionnaires assessing eating and general psychopathologic symptoms, participated in interviews assessing Axis I disorders and childhood abuse, and provided blood samples for genotyping. Data on lifetime Axis I disorders were analyzed using latent class analysis, and resulting classes were compared on eating and psychopathologic symptoms, 5-HTTLPR genotype, and childhood abuse. The study was conducted from June 2002 to October 2006.

Results: The analysis yielded a model with 2 classes: a first class labeled low comorbidity (N = 59, 66%), characterized by a high likelihood of major depressive disorder, and another class labeled high comorbidity (N = 30, 34%), characterized by a high likelihood of major depressive disorder, anxiety disorder, and substance-use disorders. The high-comorbidity class displayed significantly higher dieting preoccupations and conduct problems, and showed a greater likelihood of carrying the 5-HTTLPR S allele and of childhood abuse than did the low-comorbidity class.

Conclusion: The present results are consistent with previous findings identifying a subgroup of individuals with bulimia characterized by high psychiatric comorbidity and suggest that the 5-HTTLPR polymorphism and childhood trauma may both be pertinent to explaining the presence of greater psychiatric comorbidity in bulimia-spectrum disorders.

(J Clin Psychiatry 2008;69:981-990. Online Ahead of Print May 20, 2008.)

Received July 30, 2007; accepted Dec. 4, 2007. From the Eating Disorders Program (Mss. Richardson, Anestin, and Dandurand and Drs. Steiger, Bruce, and Israel) and the Research Centre (Drs. Steiger, Schmitz, Joober, Bruce, Israel, and Howard and Ms. de Guzman), Douglas Mental Health University Institute; the Psychiatry Department (Drs. Steiger, Schmitz, Joober, Bruce, and Israel) and the Psychology Department (Ms. Richardson and Dr. Steiger), McGill University; and the Department of Social and Preventive Medicine, University of Montreal (Dr. Gauvin), Montreal, Quebec, Canada.

This research was supported by grant MOP-57929, awarded to Dr. Steiger by the Canadian Institutes of Health Research, and by grant SR-4306, awarded to Drs. Steiger and Joober by the Quebec government's Joint Conseil Québécois de la Recherche Social-Fonds de la Recherche en Santé Québec-Ministère de la Santé et des Services Sociaux (CQRS-FRSQ-MSSS) Program in Mental Health. Jodie Richardson was supported by a doctoral bursary from the FRSQ, and Heidi Howard was supported by a post-doctoral bursary from the Canadian Institutes of Health Research.

Preliminary results were presented at the annual meeting of the Academy for Eating Disorders; May 4, 2007; Baltimore, Md.

Acknowledgments appear at the end of this article.

Dr. Joober is a consultant and a member of the speakers/advisory boards for Pfizer and Janssen Ortho. Mss. Richardson, Anestin, Dandurand, and de Guzman and Drs. Steiger, Schmitz, Bruce, Israel, Gauvin, and Howard report no additional financial or other relationships relevant to the subject of this article.

Corresponding author and reprints: Jodie Richardson, B.Sc., Eating Disorders Program, Douglas Mental Health University Institute, 6605 LaSalle Blvd., Borough of Verdun, Montreal, Quebec, Canada H4H 1R3 (e-mail: