No correlation between aggression and platelet (3)H-paroxetine binding in obsessive-compulsive disorder patients

Different findings suggest that the serotonin (5-HT) system may be involved in both the regulation of aggression and the pathophysiology of obsessive-compulsive disorder (OCD). Our study aimed to evaluate the aggressive features of a group of OCD patients and to explore possible correlations with a serotonergic marker, namely platelet 5-HT transporter. Psychopathological and biological patterns were compared with those of a group of healthy controls and those of patients with major depression. Twenty-one patients affected by OCD, 21 by depression and 21 healthy controls were included in the study. Aggressive features were measured by means of the Buss and Durkee Hostility Inventory (BDHI). The platelet 5-HT transporter was evaluated by means of the (3)H-paroxetine binding parameters (maximum binding capacity, B(max) and dissociation constant, K(d)). The OCD patients showed a total score on the BDHI not significantly different from that of healthy controls and lower than that of depressed patients. The factor profile was similar in the 3 groups, but higher in the depressed patients. The irritability, resentment, guilt, negativism and suspiciousness factors were significantly more pronounced in depressed patients. Some sex-related difference in single factors were also observed. The B(max) of (3)H-paroxetine binding was lower in OCD patients than in depressives or healthy controls. OCD patients were more similar to healthy controls than to depressed patients with regard to aggressive features measured by means of the BDHI. This suggests that aggression in OCD is a complex phenomenon that probably requires specific instruments of evaluation.