Laxative misuse and behavioral disinhibition in bulimia nervosa

Abstract

Objective: Various reports suggest that purging with laxatives is associated with greater behavioral impulsivity in bulimia nervosa (BN) patients. We investigated the extent to which laxative misuse corresponds to specific impulse-control problems.

Method: Participants included bulimic women who misuse laxatives (BNL+; n = 12), bulimic women who do not misuse laxatives (BNL-; n = 33), and healthy normal eaters (NE; n = 26). Participants completed the Go/No-Go discrimination task (a well-validated computerized measure of response disinhibition), as well as self-report questionnaires of impulsivity, eating symptoms, and general psychopathology.

Results: Compared with the other groups, the BNL+ group made more commission errors on the Go/No-Go under cues for punishment, indicating they were more disinhibited when faced with possible negative outcomes. Compared with the BNL- group, the BNL+ group was also more likely to differ from the NE group on self-reported impulsivity. There were no differences between the two bulimic groups on eating symptoms and the three groups did not differ in terms of general psychopathology.

Discussion: Findings suggest that, controlling for eating symptoms and psychopathology, laxative misuse among BN patients is associated with difficulty inhibiting incorrect responses in the face of perceived threats.