Impulsiveness and lack of inhibitory control in eating disorders

Eating disorders are considered to lie on a spectrum of disorders with varying degrees of obsessive-compulsive and impulsive traits. Restrictive anorexia nervosa patients (AN-R) are thought to belong to the obsessive pole of the spectrum, and purging-anorexia (AN-P) and bulimia nervosa (BN) patients to the impulsive pole. In this study we have compared impulsive traits in three groups of eating disordered patients (total N=56) and a control group of 83 female students. Information about impulsive traits and lack of inhibitory control was gathered by means of standardized rating scales (Eysenck's Impulsiveness Scale, Barrett's Impulsiveness Scale, and Carver and White's BIS/BAS scale) and a behavioral measure of impulsiveness (stop-go task). On the questionnaires AN-R patients reported to be less impulsive than controls, AN-P and BN patients. In the stop-go task, we did not find significant differences between the different groups. Correlations between self-reported measures of impulsiveness and behavioral measures were not significant.

Our results from the self-report measures are at odds with the behavioral measures certainly in the AN-R group. Perhaps the latter patients' distorted self-perception and/or self-description may explain this discrepancy.