Changes of Serum Insulin-like Growth Factor-2 Response to Negative Symptom Improvements in Schizophrenia Patients Treated with Atypical Antipsychotics

Abstract

Accumulating evidence suggests that a disruption of early brain development, in which insulin-like growth factor-2 (IGF-2) has a crucial role, may underlie the pathophysiology of schizophrenia. Our previous study has shown that decreased serum IGF-2 was correlated with the severity of psychopathology in patients with schizophrenia. Here we conducted a prospective observation trial to investigate the effects of atypical antipsychotics on serum IGF-2 level and its relationship with clinical improvements in schizophrenia patients. Thirty-one schizophrenia patients with acute exacerbation and 30 healthy individuals were recruited in this study. Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) and serum IGF-2 levels were determined using ELISA. We found that schizophrenia patients with acute exacerbation had lower serum IGF-2 levels than control individuals at baseline (P<0.05). After 2 months of atypical antipsychotic treatment, a significant improvement in each PANSS subscore and total score was observed in patients (all P<0.01), and the serum IGF-2 levels of patients were significantly increased compared with those at baseline (203.13±64.62 vs. 426.99±124.26 ng/mL; t =−5.044, P<0.001). Correlation analysis revealed that the changes of serum IGF-2 levels in patients were significantly correlated with the improvements of negative symptoms (r=−0.522, P=0.006). Collectively, our findings demonstrated changes of serum IGF-2 response to improvements of negative symptoms in schizophrenia patients treated with atypical antipsychotics, suggesting that serum IGF-2 might be a treatment biomarker for schizophrenia.