Divergent responses to fluoxetine from two compulsive, food-related conditions: bulimia nervosa and compulsive water drinking.

Background: The association of compulsive water drinking with bulimia nervosa is rarely encountered. Nevertheless similar behavior patterns could involve a common pathophysiological mechanism.

Methods: A case report with the association of those two disorders is described. Treatment with fluoxetine was introduced to alleviate the compulsive aspects of those disorders.

Results: Fluoxetine had a positive effect on bulimia nervosa but none on compulsive water drinking.

Conclusions: The different response to pharmacologic treatment could mean that bulimia nervosa and compulsive water drinking are based on different physiological mechanisms.