The Relation Between Symptoms of Bulimia Nervosa and OCD: A Study of Aversiveness Sensitivity

Studies investigating the comorbidity of bulimia nervosa (BN) and obsessive compulsive disorder (OCD) suggest that the disorders may have shared etiological factors that partially account for their co-occurrence. One of these factors may be a hyper-responsive aversive system. According to Lang’s theory of emotion (Lang, 1995), activation of the aversive system leads to withdrawal when an organism is faced with unpleasant, threatening stimuli. One of the correlates of aversive system activation is increased defensive reflexes, such as startle. Thus, startle response can be viewed as a physiological indicator of aversiveness sensitivity. If BN and OCD share a heightened sensitivity to aversiveness, aversive stimuli may potentiate startle in individuals with BN and OCD. The present study examined whether heightened aversiveness sensitivity helps to elucidate the relation between OCD and BN. As a primary aim of this study, startle response was evaluated during two types of aversive pictures - disorder-specific aversive pictures (e.g., food cues for individuals with BN tendencies, contamination cues for individuals with OCD tendencies) and non-specific aversive pictures (e.g., threat). As a secondary aim, temporal parameters of the emotional response to aversive stimuli were examined by assessing startle response in anticipation of and following picture cues. The sample included 117 undergraduate females with normally-distributed BN and OCD symptoms. Results indicated that body image and contamination concerns predicted increased disorder-specific aversiveness sensitivity in those with elevated BN and OCD symptoms. We also found that the co-occurrence of elevated BN and OCD symptoms predicted increased general sensitivity. Clinical and research implications are discussed.