RESEARCH ARTICLE Obsessive Compulsive Disorder as a Cause of Atypical Eating Disorder: A Case Report Frederico Duarte Garcia 1,2 * , Emmanuelle Houy-Durand 1 , Florence Thibaut 2 & Pierre Dechelotte 1 1 Nutrition Unit, Biomedical Research Institute EA 4311, Rouen University Hospital, France 2 Psychiatry Unit, Biomedical Research Institute, Rouen University Hospital, France Abstract Objective: To describe a case of an atypical eating disorder with a diagnosis of obsessive-compulsive disorder and discuss the phenomenological and neurobiological aspects links between the disorders. Case: a 20-year-old Caucasian woman presented with obsessive-compulsive disorder followed by altered eating habits with major weight loss and amenorrhea. The medical workup, treatment and outcome are described. Using cognitive-behavioural therapy, clomipramine and enteral nutrition, weight gain and disappearance of restrictive and obsessive-compulsive behaviours were obtained. Conclusion: Available evidence in the literature suggests a continuum in eating disorder and obsessive compulsive disorder. Our case illustrates that an obsessive-compulsive disorder may precede or precipitate the development of an eating disorder and highlights the importance of a precise differential diagnosis in eating disorders clinics. Copyright # 2009 John Wiley & Sons, Ltd and Eating Disorders Association. Keywords anorexia nervosa; obsessive compulsive disorder; atypical eating disorder *Correspondence Dr Frederico Duarte Garcia, Nutrition Unit, 1 rue de Germont, 76031 Rouen CEDEX, France. Tel: þ33 632456598, Fax: þ33 235710238. Email: frederico.garcia@chu-rouen.fr; fdgarcia@pop.com.br Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/erv.961 Introduction Obsessive-compulsive disorder (OCD) is characterised by the presence of either obsessions or compulsions (American Psychiatric Association. Task Force on DSM- IV, 2000). Available evidence in the literature suggests a continuum between eating disorders(ED), especially anorexia nervosa (AN) and obsessive compulsive disorders, the former being generally considered as the primary disease and the latter as comorbidity (Bellodi & Cavallini, 2001). Conversely, the OCD symptoms could interfere with eating habits and lead to a clinical presen- tation that resembles that of an eating disorder. In those cases, weight loss may occur as a consequence of the obsessions or as a result of the time wasted in rituals, or both, rather than a consequence of reduced food intake. Case report A 26-year-old Caucasian woman was referred to our Eating Disorders Unit for the assessment and treatment of severe weight loss considered as an ‘atypical eating disorder’. She had a normal development and after successful university post-graduation she worked in a state institution before the accentuation of her symptoms. Family history revealed that her mother and a younger sister were treated with medication and psychotherapy for OCD. 444 Eur. Eat. Disorders Rev. 17 (2009) 444–447 ß 2009 John Wiley & Sons, Ltd and Eating Disorders Association.