GROWTH-HORMONE RESPONSE TO APOMORPHINE IN OBSESSIVE-COMPULSIVE DISORDER

Several lines of evidence suggest that dopamine plays a role in the pa thophysiology of obsessive-compulsive disorder (OCD). Indeed, some tri als have shown the efficacy of neuroleptic addition in the treatment o f OCD patients, In this study, we assessed the growth hormone (GH) res ponse to 0.5 mg apomorphine(sc) in 8 drug-free inpatients (6 male, 2 f emale; mean age +/- SD = 34.7 +/- 12.6) meeting DSM-III-R criteria for OCD without major depression and compared their responses with those of 8 healthy male volunteers (mean age = 27.1 +/- 8,5), The 2 groups d id not differ in their mean GH peak response: 12.4 +/- 9.7 ng/mL in OC D patients versus 21.1 +/- 14.2 ng/mL in normal controls (F = 0.9, df 1, 14, P = 0.37). These results do not support the hypothesis of dopam inergic overactivity in OCD. In fact, the completely blunted GH respon se to apomorphine in 2 OCD patients suggests the biological heterogene ity of OCD. Some dopaminergic disturbances could be observed in patien ts with comorbid diagnoses or patients unresponsive to serotonin reupt ake inhibitors, but the results of this study require confirmation fro m a larger sample with a precise assessment of comorbidity.