Growth hormone response to growth hormone-releasing hormone stimulation in obsessive-compulsive disorder

Two groups of 30 patients with obsessive-compulsive disorder and 30 age- and sex-matched healthy control subjects were given a growth hormone-releasing hormone (GHRH) stimulation test to determine: (1) whether the downstream function of the somatotropic axis (growth hormone = GH, somatomedin-C = SMD-C) was impaired; (2) what might be the central alteration responsible for such impairment; and (3) whether alterations might be linked to the etiopathogenesis of the disease. Basal values of GH and SMD-C were the same in patients and control subjects, but GH responses to GHRH stimulation were significantly lower in patients than in control subjects. The absence of a pathology of basal GH and SMD-C concentrations indicates that the blunted GH responses to GHRH stimulation are not due to a negative feedback mechanism and suggests that a central neurotransmitter-neuropeptide pathology might be involved in the phenomenon.