Chapter 39: Personality and Eating Disorders

Personality is fundamentally understood through two primary, biologically-based motivational systems: the tendency to avoid aversive stimuli (Avoidance) and the tendency to approach appetitive stimuli (Approach). Avoidance tendencies, often measured as Neuroticism, trait anxiety, or harm avoidance, typically characterize women who engage in highly restrictive eating and maintain a low body weight, such as those with anorexia nervosa,. These traits align with the frequent co-morbidity of Cluster C Personality Disorders (PDs), which are characterized by inhibition and fearfulness, common across all forms of disordered eating,. Longitudinal studies support that traits like obsessiveness, negative affect, and perfectionism serve as predisposing vulnerability factors for disordered eating behaviors. Conversely, Approach tendencies, characterized by traits like impulsivity and sensation-seeking, are more strongly associated with binge and purge behaviors, aligning with the high co-morbidity of Cluster B PDs, which reflect general tendencies toward dysfunctional approach,. Given the significant heterogeneity, overlap in symptoms, and diagnostic fluidity seen within the current symptom-based classification system, the chapter highlights that sub-grouping based on underlying personality traits may be more effective in understanding etiology and prognosis than relying solely on DSM-IV diagnoses,. Research consistently identifies three key personality profiles: the High Functioning/Perfectionist group, the Overcontrolled/Avoidant group (often associated with restricting anorexia nervosa), and the Impulsive/Dysregulated group (more common in binge-purge subtypes like bulimia nervosa),. Further exploration into the facets of impulsivity reveals that it is not a monolithic concept, but includes specific traits like Reward Drive, reflecting heightened sensitivity to rewarding stimuli such as palatable foods, and Urgency (specifically negative urgency), defined as the tendency to act rashly in order to alleviate negative mood states,. Understanding whether binge episodes are driven by heightened reward sensitivity or by the need to regulate negative affect suggests functionally distinct emotional motives leading to the same observable behavior. Ultimately, focusing on these specific personality traits, particularly those related to impulse control and mood intolerance, offers the potential to tailor interventions and enhance the efficacy of treatment and prevention programs by addressing relapse triggers.