Higher BDNF plasma levels are associated with a normalization of memory dysfunctions during an antidepressant treatment.

One important symptom of patients with major depressive disorder (MDD) is memory dysfunction. However, little is known about the relationship between memory performance and depression severity, about the course of memory performance during antidepressant treatment as well as about the relationship between memory performance and brain-derived neurotrophic factor (BDNF). Memory function [learning and delayed recall) was assessed in 173 MDD patients (mean age 39.7 ± 11.3 years] treated by a pre-defined treatment algorithm within the early medication change (EMC) study at baseline, days 28 and 56. Depression severity was assessed in weekly intervals, BDNF plasma levels were measured at baseline, days 14 and 56, BDNF exon IV and p11 methylation status at baseline. Linear mixed regression models revealed that the course of depression severity was not associated with the course of learning or delayed recall in the total group. 63 (36%) of the investigated patients showed memory deficits (percent range ≤ 16) at baseline. Of those, 26(41%) patients experienced a normalization of their memory deficits during treatment. Patients with a normalization of their delayed recall performance had significantly higher plasma BDNF levels (p = 0.040) from baseline to day 56 than patients with persistent deficits. Baseline BDNF exon IV promoter and p11 gene methylation status were not associated with memory performance. Our results corroborate a concomitant amelioration of learning and delayed recall dysfunctions with successful antidepressant therapy in a subgroup of patients and support a role of BDNF in the neural mechanisms underlying the normalization of memory dysfunctions in MDD. ClinicalTrials.gov number: NCT00974155; EudraCT: 2008-008280-96.

Plasma brain-derived neurotrophic factor (pBDNF) and executive dysfunctions in patients with major depressive disorder.

Objectives: Executive dysfunctions are frequently seen in patients with major depressive disorder (MDD) and normalise in many cases during effective antidepressant therapy. This study investigated whether a normalisation of executive dysfunctions during antidepressant treatment correlates with or can be predicted by clinical parameters or levels of brain-derived neurotrophic factor (BDNF).Methods: In 110 MDD patients with executive dysfunctions (percentile <16), executive functions and plasma BDNF levels were analysed at baseline, and days 14 and 56 of an antidepressant treatment. BDNF exon IV and P11 methylation status was studied at baseline.Results: Eighty patients (73%) experienced a normalisation of executive dysfunctions, while 30 (27%) suffered from persistent dysfunctions until day 56. Patients with persistent dysfunctions had significantly higher HAMD scores at days 14 and 56, and lower plasma BDNF levels at each time point than patients with a normalisation of dysfunctions (F1= 10.18; P = 0.002). This was seen for verbal fluency, but not processing speed. BDNF exon IV and p11 promoter methylation was not associated with test performance.Conclusions: Our results corroborate a concomitant amelioration of executive dysfunctions with successful antidepressant therapy and support a role of BDNF in the neural mechanisms underlying the normalisation of executive dysfunctions in MDD.ClinicalTrials.gov number: NCT00974155; EudraCT: 2008-008280-96.

Randomized controlled study of early medication change for non-improvers to antidepressant therapy in major depression--The EMC trial.

Patients with Major Depressive Disorder (MDD) and no improvement after two weeks of antidepressant pharmacotherapy have a high risk of treatment failure. The aim of the study was to determine whether an early medication change (EMC) strategy is superior to a guideline-based treatment in MDD patients without improvement after two weeks of antidepressant pharmacotherapy. Eight-hundred-and-eighty-nine patients with MDD were enrolled, 879 patients received the SSRI escitalopram. Of those, 192 patients had no improvement, defined as a reduction of < 20% on the Hamilton Depression Rating Scale (HAMD-17) after 14 days of treatment, and were randomly assigned to open treatment with the EMC strategy (n = 97; venlafaxine XR for study days 15-56; in case of sustained non-improvement on day 28, lithium augmentation for days 29-56) or TAU (n = 95; escitalopram continuation; non-responders on day 28 were switched to venlafaxine XR for four weeks, i.e. days 29-56). The primary outcome was remission (HAMD-17 ≤ 7) after 8 weeks of treatment as assessed by blinded raters. Remission rates were 24% for EMC and 16% for TAU, which was not significantly different (p = 0.2056). Sensitivity analyses for the primary and secondary effectiveness endpoints consistently showed favorable results for patients randomized to EMC. The results confirm data from post-hoc analyses of clinical trials showing that early non-improvement identifies patients who likely need alternate interventions. However, the herein used two-step switch/augmentation strategy for this risk group was not more effective than the control intervention. Alternate strategies and other design aspects are discussed in order to support researchers addressing the same research question.