Brain-derived neurotrophic factor and its serum levels in schizophrenic patients.

Introduction: Neurotrophins have an important role in regulating the development and maintenance of the peripheral and central nervous systems' function. Thus, the neurotrophin hypothesis of schizophrenia has postulated that the changes in the brain of schizophrenic patients are the result of disturbances of developing processes involving these molecules.

Aim: We analyse in the present study the changes in the serum levels of brain-derived neurotrophic factor (BDNF) in schizophrenic patients as possible epiphenomena of underlying alterations of the neurotrophic factor in central nervous system, reflecting its role in the pathophysiology of schizophrenia.

Patients And Methods: Twenty-one schizophrenic patients satisfying the DSM-IV criteria for diagnosis of schizophrenia were enrolled in the study. The control group consisted of 28 age-matched mentally healthy subjects. Serum BDNF levels were determined in patients and normal controls using ELISA (Chemicon International, USA & Canada). The data were analyzed statistically with Student's t- test in SPSS 9.0.

Results: The serum BDNF levels were lower in the schizophrenic patients than in the control subjects, reaching statistically significant difference (t = 2.72, p = 0.009). Female patients had lower serum BDNF levels than the male patients but the difference fell short of statistical significance (t = 0.1, p = 0.9).

Conclusions: The BDNF reduction in serum indicates a potential deficit in neurotrophic factor release in patients with schizophrenia and support the concept that BDNF might be associated with schizophrenia.