Childhood abuse and platelet tritiated-paroxetine binding in bulimia nervosa: implications of borderline personality disorder.

BACKGROUND Co-occurrence of bulimia nervosa and borderline personality disorder has been attributed to shared factors, including childhood abuse and disturbances in central serotonin (5-hydroxytryptamine; 5-HT) mechanisms. To explore this notion, we conducted a controlled assessment of childhood abuse and 5-HT function in bulimics with and without borderline personality disorder. METHOD Forty patients with bulimia nervosa, confirmed with the Eating Disorders Examination interview (14 with borderline personality disorder and 26 without), and 25 normal-eater controls were assessed for clinical symptoms (eating disturbances, mood lability, impulsivity, and dissociation) and childhood sexual and physical abuse. We also conducted tests of platelet tritiated-paroxetine binding in blood samples from 27 of the bulimics (11 with borderline personality disorder and 16 without) and 16 of the controls. RESULTS Relative to normal eaters, bulimics showed greater affective instability, overall impulsivity, and a history of physical abuse. However, borderline bulimics alone showed elevated motor impulsivity, dissociation, and rates of sexual abuse. Paroxetine-binding tests indicated no differences attributable to comorbid borderline personality disorder, instead linking bulimia nervosa with or without borderline personality disorder to substantially reduced 5-HT transporter density. CONCLUSION Results suggest relatively autonomous pathologic entities: one, relevant to bulimia nervosa, being associated with abnormal 5-HT transporter function and affective instability, but relatively independent of childhood sexual abuse; another, relevant to borderline personality disorder, onto which sexual abuse, dissociative symptoms, and behavioral impulsivity converge. We propose that abnormal 5-HT function may, however, constitute one basis for the frequent co-occurrence of bulimic and borderline disturbances.