Early reactions of brain-derived neurotrophic factor in plasma (pBDNF) and outcome to acute antidepressant treatment in patients with Major Depression.

In Major Depressive Disorder, a growing data base suggests that the onset of antidepressants' action can be detected by improvement of depressive symptoms in the first 10-14 days of treatment. Previous studies showed that the mean concentration of the brain-derived neurotrophic factor (BDNF) in blood increases during antidepressant treatment and positively correlates with amelioration of MDD symptoms. We previously showed an association between very early changes of the serum BDNF concentration and treatment outcome (Tadić et al., 2011. Prog Neuropsychopharmacol Biol Psychiatry 35, 415-420). However, no study has yet investigated whether BDNF concentration in plasma increases in the early course of treatment and enables the prediction of final treatment outcome. The goal of this study was to investigate in MDD patients, whether the change of pBDNF in the early course of treatment is a specific and sensitive marker for final treatment outcome. For this purpose, we performed a naturalistic pilot study with 39 inpatients with MDD according to DSM-IV. Depression severity and pBDNF were measured in weekly intervals from baseline (EP) to endpoint (EP, max. week six) with the 21-item Hamilton Depression Rating Scale (HAMD-21) and enzyme-linked immunosorbent assay (ELISA), respectively. According to ROC-analysis, the best cut-off value for the prediction of response at EP is an increase of 338 pg/ml or 126%, respectively, of pBDNF between BL and day 7. The single markers pBDNF change and HAMD-21 improvement from BL-d7 predicted later treatment outcome with moderate to high sensitivity and specificity (pBDNF: 42% and 96%, resp.; HAMD improvement: 83% and 65%, resp.). The combined marker early pBDNF change plus HAMD-21 improvement at day 7 increased the specificity for response to 100%. Our data provide first preliminary evidence that an early change of pBDNF in conjunction with early improvement might be a peripheral marker predictive for treatment outcome in patients with MDD. This has to be confirmed in further investigations. This article is part of a Special Issue entitled 'Anxiety and Depression'.