Potential abnormalities in molecular forms of growth hormone in schizophrenia: a pilot study

Growth hormone has been investigated in numerous studies involving patients with schizophrenia but has been measured only by radioimmunoassay (RIA). There have been no consistent abnormalities differentiating patients with schizophrenia from normal controls. In the current study, growth hormone (GH) variants were measured by Western blotting techniques, which resulted in the quantitation of 4 GH size variants: 27K (27,000 Daltons), 22K, 20K, and 17K. In the entire sample of 17 schizophrenic subjects, all GH variants were significantly higher than in the 14 normal controls. While there were no significant differences between the 2 groups in RIA GH values, the RIA values were generally higher in the schizophrenic group. In a subset of 12 schizophrenic patients whose RIA values were approximately equal to the controls, both the 27K and 22K GH variants remained significantly higher in the patient group. In the schizophrenic group, none of the GH variants or RIA GH changed significantly after 1 week of treatment with neuroleptic medication. These preliminary results suggest that certain GH forms may be elevated in schizophrenia, but further studies are needed.