Laxative misuse and behavioral disinhibition in bulimia nervosa.

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.