A Longitudinal Study of Serum Brain-Derived Neurotrophic Factor Levels in First-Episode Schizophrenia

Biomarkers identified for psychosis might allow for early diagnosis, more accurate prognosis, and tailored individualized interventions. Brain-derived neurotrophic factor (BDNF) is suggested to be a likely candidate biomarker for the diagnosis and treatment evaluation in psychosis. The aims of present study were to examine the levels of serum BDNF in both patients with first-episode psychosis (FEP) and in healthy controls for a year, and to investigate the association between BDNF with symptom severity and remission status.

A sample of 31 healthy controls and 29 patients with FEP were included in this study. Diagnoses were ascertained on the Structured Clinical Interview for DSM-IV-TR. Symptom severity was assessed on the Positive and Negative Syndrome Scale. Serum levels of BDNF were measured using enzyme-linked immunosorbent assay method at recruitment and at 3-, 6-, and 12-month time points.

Serum BDNF levels in both groups did not differ significantly over time. Baseline BDNF levels in patients with FEP did not correlate with symptom severity and neither baseline BDNF level nor its relative change at 3-month predicted remission status at 6- and 12-month follow-up visits. Of note, we observe similar fluctuations in serum BDNF levels in both patients and healthy controls over the 12-month period.

Findings from our study did not support a role for serum BDNF as a biomarker for patients with FEP. Because of the polygenic nature of psychosis, we recommend a comprehensive multimarker profile consisting of markers from representative components of mediated neuronal nutrition, neuroimmunology, and neurologic functional deficit to allow for better predictive power.