Effect of treatment on serum brain–derived neurotrophic factor levels in depressed patients

Abstract

Researchers have reported that serum brain-derived neurotrophic factor (sBDNF) of drug-free depressed patients are lower than those of healthy controls and proposed that low sBDNF levels might reflect failure of neuronal plasticity in depression. In this study, we compared sBDNF levels of depressed patients (n = 28) before and after 8 weeks of antidepressant treatment, with those of healthy controls (n = 18) to test the hypothesis that initially low sBDNF levels of drug-free depressed patients will increase parallel with their clinical response to antidepressant treatment. The severity of depression and response to treatment were assessed with Hamilton Rating Scale for Depression (HAM-D). sBDNF was assayed with the sandwich ELISA method. Baseline sBDNF levels of patients (mean, 20.8 ng/ml; [S.D., 6.7]) were significantly lower than those of controls (mean, 26.8 ng/ml; [S.D., 9.3]; p = 0.015), and were negatively correlated with HAM-D scores (r = -0.49, p = 0.007). After 8 weeks of treatment, sBDNF levels of patients had increased significantly (mean, 33.3 ng/ml; [S.D., 9.9]; p < 0.001) and no longer differed from those of controls. These results support the hypothesis that BDNF might play a critical role in the pathophysiology of major depressive disorder and successful antidepressant treatment increases the attenuated BDNF levels in depressed patients.

Consensus paper of the WFSBP Task Force on Biological Markers: Biological Markers in Depression

“…All of these treatments increase BDNF at least in rats, and likely in humans, as supported by multiple threads of evidence, e.g., direct measurements of BDNF in the bloodstream (Karege et al 2002(Karege et al , 2005Shimizu et al 2003). Treatment of depressed patients with antidepressants increases the reduced pretreatment serum BDNF levels close to the levels of normal controls (Aydemir et al 2005;Gervasoni et al 2005;Gonul et al 2005). Some results suggest that the combination of exercise and antidepressant treatment may have significant neurochemical and behavioural effects.…”

Interaction between BDNF and Serotonin: Role in Mood Disorders

“…The resultant decrease in activity in excitatory neurons could underlie the observed downregulation of BDNF. Moreover, several studies have shown that SSRI treatment, which increases synaptic serotonin levels, can reverse the stress-induced downregulation of BDNF gene expression (Aydemir et al, 2005;Gervasoni et al, 2005;Gonul et al, 2005). In summary, stress generally inhibits BDNF gene expression, and some evidence suggests that this effect is, at least in part, mediated by a reduction in serotonin signaling.…”

Is it time to reassess the BDNF hypothesis of depression?

“…[50][51][52] Furthermore, serum BDNF in living depressed patients is abnormally low, but can be restored following pharmacological antidepressant treatment. [53][54][55][56][57][58] The BDNF hypothesis of depression: the argument against…”