BDNF and schizophrenia: Interestingly, the brain-derived neurotrophic factor (BDNF), which regulates the survival and growth of neurons and influences synaptic efficiency and plasticity, seems also to be involved, since peripheral (blood) BDNF levels have been consistently found to be reduced in medicated and drug-naïve patients with schizophrenia [76], and in FEP patients [77].