Impulsivity and overeating: a closer look at the subscales of the Barratt Impulsiveness Scale

Impulsivity can be defined as a predisposition toward rapid, unplanned reactions to internal or external stimuli regardless of negative consequences of these reactions for the impulsive individual or for others (Moeller et al., 2001). It is a multifaceted construct and there is a range of methods available for its measurement. Two of the most often used methods are selfreport instruments and behavioral tasks (e.g., go/no-go tasks and delay discounting tasks). Self-reported impulsivity is positively correlated with impulsive reactions in behavioral measures, yet correlations are often weak and inconsistent (Logan et al., 1997; Lijffijt et al., 2004; Enticott et al., 2006; Reynolds et al., 2006; Cyders and Coskunpinar, 2011). It is assumed that self-report questionnaires represent impulsivity as a stable trait while behavioral tasks are subject to state-dependent variations. Nonetheless, both self-report and behavioral measures indicate that high impulsivity is a risk factor for a range of maladaptive behaviors, including overor binge eating (Guerrieri et al., 2008; Waxman, 2009). Beyond the fact that self-report and behavioral measures seem to capture different aspects of impulsivity, conceptualizations also vary between the different self-report instruments. For instance, two of the most widely used impulsivity questionnaires are the UPPS Impulsive Behavior Scale (Whiteside and Lynam, 2001) and the Barratt Impulsiveness Scale (BIS-11, Patton et al., 1995). The UPPS assesses impulsivity on the subscales urgency (acting rashly under conditions of negative affect), lack of premeditation (difficulty in thinking and reflecting on consequences of an act), lack of perseverance (inability to remain focused on a task), and sensation seeking (tendency and openness to try and enjoy exciting or dangerous activities). The BIS-11 assesses impulsivity on the subscales attentional impulsivity (inability to focus attention or concentrate), motor impulsivity (acting without thinking), and non-planning impulsivity (lack of future orientation or forethought). Both questionnaires are highly correlated with each other (r = 0.67), but correlations between their subscales are only weak and inconsistent, supporting the notion that both measures cover different aspects of impulsivity (Meule et al., 2011). Beyond using the UPPS total score, relationships between UPPS subscales and eating behavior have been investigated and it has been found that urgency in particular is predictive for eating problems, e.g., binge eating (Fischer et al., 2003, 2008; Smith et al., 2007; Mobbs et al., 2008; Manwaring et al., 2011; Dir et al., 2013). To date, similar clear-cut results for the BIS-11 are missing. Although it is widely used, most studies only use its total score for analysis. In this brief opinion piece I would like to advocate the use of BIS-subscales. That is, researchers may benefit from examining relationships between BIS-subscales and eating behavior in greater detail. Only a few studies have done this as yet. For instance, differential relationships between subscales of the BIS-11 and eating disorder symptomatology have been found in clinical samples. Patients with binge eating disorder had higher scores on the motor impulsivity subscale compared to healthy controls, but did not differ on the other two subscales (Nasser et al., 2004). Two studies compared scores on the BIS-11 between patients with bulimia nervosa (BN), anorexia nervosa— binge/purge type (AN-BP), anorexia nervosa—restrictive type (AN-R), and healthy controls. In a first study by Rosval and colleagues (2006), eating disorder groups did not differ from each other on the attentional impulsivity subscale, but all had higher scores than controls. With regard to motor impulsivity, the two groups with binge eating behavior (BN and AN-BP) had higher scores than both the AN-R group and controls. The BN group also had higher scores on nonplanning impulsivity than both the AN-BP and AN-R group, but did not differ from controls (Rosval et al., 2006). In a second study (Claes et al., 2006), the two groups with binge eating (BN and AN-BP) reported higher attentional impulsivity compared to controls. With regard to motor impulsivity, AN-BP, BN, and controls had higher scores than AN-R. The BN group and controls also had higher scores on non-planning impulsivity than AN-R (Claes et al., 2006). In sum, it appears that eating disorder patients with binge eating behaviors have higher BIS-11 scores, particularly on its motor and attentional impulsivity subscales, compared to patients with restrictive eating behavior and controls. Studies investigating non-clinical samples also revealed differential associations between BIS-11 subscales and various measures of eating behavior. For example, Lyke and Spinella (2004) examined the associations between the BIS-11 and the Eating Inventory (formerly Three-Factor Eating Questionnaire, Stunkard and Messick, 1985). A small positive correlation was found between the hunger subscale and attentional impulsivity. Furthermore, both attentional and motor impulsivity were correlated with disinhibition (Lyke and Spinella, 2004).