Impulsivity and decision making in eating disorders

Objective. Decision making is impaired in Eating Disorders (ED). In the current study we aimed to assess the relationship between decision making, impulsiveness and temperamental traits in a sample of patients with ED. Method. Fifty-one patients with ED, namely 14 anorexic-restricting type patients (AN-R); 13 anorexic-binge/purge type patients (AN-BP); 14 bulimic patients (BN); 10 patients with binge Eating Disorder (BED), and 28 healthy controls (HC) were assessed using the Iowa Gambling Task (IGT). Temperament and Character Inventory (TCI) and Barratt Impulsiveness Scale (BIS-11) were used to assess temperamental traits and impulsivity. Hamilton Depression Rating Scale (HAM-D) and Frontal Assessment Battery (FAB) were administered to evaluate depressive symptomatology and integrity of executive functions. Results. AN-R, AN-BP and BN showed poorer IGT performance than HC, while BED didn’t perform significantly different from HC. In the overall group of patients, performance was correlated with Persistence (P), Novelty Seeking (NS), BIS and ‘Fab go no go’ scores. AN-BP and BN performed similarly, and their results were correlated with P score. AN-R and BED performances were correlated respectively with ‘Fab go no go’ and NS scores. Furthermore, AN-BP and BN patients showed similar profiles both on impulsiveness and temperamental scales. Conclusions. Our results confirm a specific deficit in decision making for AN-R, AN-BP and BN. Impaired decision making might be explained by different mechanisms in AN-R patients on one hand and AN-BP and BN patients on the other. Poor decision making in AN-R patients seems to be related to a cognitive style characterized by rigidness, scarce abilities in set shifting and attentional impulsivity. This profile seems to be confirmed by our findings with TCI and BIS such as high persistence, low reward dependence and high attentional impulsiveness. In AN-BP and BN patients poor decision making correlates with novelty seeking, attentional impulsiveness, motor impulsiveness and non planning impulsiveness. Furthermore, our study shows how AN-BP present intermediate scores between AN-R and BN regarding temperamental assessment; impulsivity and decision making strategies are very similar in AN-BN and BN. Our study fail to highlight differences between BED and HC in decision making and impulsivity except for one of the two dimension of Novelty Seeking (NS2), that is correlated with higher temperamental impulsivity