Numerous studies have examined the short- and long-term effects of antipsychotics on the synthesis and secretion of such neuropeptides as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) or glial cell line–derived neurotrophic factor (GDNF), which are very important neuroregulators in the etiology and treatment of schizophrenia [8, 25, 26]. Here, GDNF is linked to schizophrenia.