Nerve growth factor in never-medicated first-episode psychotic and medicated chronic schizophrenic patients: possible implications for treatment outcome

Nerve growth factor (NGF) has been found to play a crucial role in the neuroplasticity of predominantly cholinergic neurons in brain development, and neuronal survival following brain injury, which reflect in cognitive performance. Wide ranges of neurodevelopmental abnormalities have been reported in schizophrenic patients, who also show poor cognitive performance. We report plasma NGF levels in never-medicated first-episode psychotic (FEP; N=24) and chronic medicated schizophrenic patients (N=24). NGF levels were determined in plasma by Enzyme-Linked ImmunoSorbent Assay (ELISA). Plasma NGF levels were significantly lower in both FEP and medicated chronic patients as compared to normal subjects (P<0.001). However, NGF levels were significantly higher in chronic schizophrenic patients, which were treated with antipsychotics as compared to FEP (P<0.05). Moreover, NGF levels in chronic patients treated with atypical antipsychotics were markedly higher as compared to patients treated with typical antipsychotics (P<0.05). Lower NGF levels in FEP patients at the onset of psychosis may have implications for the neurodevelopmental abnormalities. However, higher NGF levels in chronic patients treated with atypical antipsychotics may have implications for the treatment outcome.