Brain-derived neurotrophic factor (BDNF) in serum of patients with mania, major depression and healthy controls

Recent findings have suggested an involvement of brain-derived neurotrophic factor (BDNF) in the pathogenesis of major depression. BDNF is an endogenous protein involved in neuronal survival and synaptic plasticity. The present pilot study assessed to our knowledge for the first time BDNF serum concentrations in 8 patients during a manic episode in bipolar disorder in comparison to 16 depressive patients and 30 healthy controls. Mean serum levels of BDNF in patients within manic episode (15,7 ng/ml; SD 3,7) were significantly decreased as compared to depressive patients (19,7 ng/ml; SD 3,3; p=0,012) and healthy controls (21,3 ng/ml; SID 5,4; p=0,009). In the control group, we found no significant age effect on mean BDNF serum values (r=-0,058; p=0,655). In conclusion, our finding of decreased BDNF serum levels in acute mania points towards a similar neurotrophic dysregulation as supposed in major depression.