Relation of Clinical Symptoms to Apomorphine-Stimulated Growth Hormone Release in Mood-Incongruent Psychotic Patients

The relationship between dopamine receptor agonist (apomorphine hydrochloride)-stimulated growth hormone (GH) release and psychotic symptoms was examined in 138 schizophrenic or schizoaffective inpatients (Research Diagnostic Criteria) and ten healthy normal volunteers. Patients were divided into three groups: those demonstrating an abnormally large GH response, an average GH response (mean GH response), or an abnormally low GH response. Abnormally large GH responses were associated with higher total psychosis scores. The increased psychosis scores observed in this group were due primarily to an increased incidence of thought disorder. Further analysis revealed a strong, positive correlation between thought disorder and the GH response. The apomorphine-stimulated GH response was also significantly related to duration of illness, an effect independent of age. Consistent with this last result, patients with a diagnosis of a DSM-III schizophreniform disorder demonstrated an elevated GH response.