Correlation of brain-derived neurotrophic factor with severity of depression and treatment response

Brain-derived neurotrophic factor (BDNF) is a modulator of neuroplasticity in the brain. It plays an important role in the pathophysiology of depression through the stress pathway. The information about correlation of BDNF levels with depression severity and treatment response in Indian population is scarce.

Consecutive 60 never treated cases with depression reporting to a large tertiary care psychiatry unit and 60 healthy matched controls from 01 January 2016 to 31 December 2016 were enrolled for study. Sociodemographic data were collected. Diagnosis of depression was carried out as per International Classification of Diseases-10^th revision (ICD-10) diagnostic criteria for research. The Hamilton Rating Scale for Depression (HRSD) was administered and accordingly scored. Venous blood for BDNF levels was collected from all cases and controls. Cases were reassessed after 04 weeks of treatment with HRSD and BDNF levels.

The mean level of serum BDNF among cases (18.56 ng/ml) was found to be reduced significantly as compared with healthy controls (32.41 ng/ml). The mean serum BDNF level (18.56 ng/ml) in never treated cases was significantly negatively correlated with the median clinical HRSD score (18.5). There was a significant increase in the mean level of serum BDNF after antidepressant treatment.

The study has revealed statistically significant low levels of serum BDNF in cases not exposed to treatment with depression compared with healthy controls. There was significant negative correlation of levels of serum BDNF with depression severity. The levels of serum BDNF significantly increased after four weeks of treatment.