Relationship between malnutrition and depression or anxiety in Anorexia Nervosa: A critical review of the literature

Background Depression, anxiety and obsessive–compulsive disorder (OCD) frequently co-occur with Anorexia Nervosa (AN). Clinical consensus admits that depressive symptoms and anxiety are the sequelae of malnutrition in AN. This review presents a critical assessment of the literature that looked into the link between depression/anxiety symptoms in relation to malnutrition and their improvement throughout the treatment. Methods We performed a systematic search of literature in Medline and PsychInfo for all the studies done to investigate psychological factors in relation to malnutrition in AN using the keywords “Anorexia Nervosa”, “depression”, “anxiety”, “obsessive-compulsive disorder” and “malnutrition”. Only articles published between 1980 and 2010 in English or French were reviewed. From the articles on AN and depression, anxiety, and/or OCD, only the ones which investigated on the relation with malnutrition were kept. This search was complemented by a manual search. We also checked the reference lists of the articles we found. Results Seven papers were analyzed and critically reviewed for their methods and results. Results are contradictory and inconsistent at all levels of assessment. Conclusions Evidence based data is very rare. From the 7 reviewed studies, none of them draw the same conclusion. This is mainly due to the large differences in the samples' populations and the studies' protocols. Future studies are needed to focus on the relationship between depression/anxiety symptoms and malnutrition. A more critical nutritional assessment should be undertaken with multiple psychological assessment scales.