RETRACTED: Electroconvulsive therapy and aerobic exercise training increased BDNF and ameliorated depressive symptoms in patients suffering from treatment-resistant major depressive disorder

Advances in Exercise in the Clinical Trials of Migraine: A Scoping Review

PURPOSE OF REVIEW

This review aimed to investigate emerging evidence regarding the effectiveness of exercise for migraines, focusing on the results of recent trials. Additionally, it explored the possibility of exercise as a treatment for migraines.

RECENT FINDINGS

Between 2020 and 2023, five, four, one, and two trials were conducted regarding the effect of aerobic exercise, anaerobic exercise, Tai Chi, and yoga, respectively, on migraine; all studies showed significant effects. Two trials on aerobic exercise showed that high-intensity exercise was similar to or slightly more effective than moderate-intensity exercise as a treatment for migraines. Three trials on anaerobic exercise reported its effectiveness in preventing migraines. Regarding efficacy, side effects, and health benefits, aerobic exercises and yoga are potentially beneficial strategies for the prevention of migraines. Further studies are needed to develop evidence-based exercise programs for the treatment of migraines.

Brain-Derived Neurotrophic Factor (BDNF) as a biomarker of treatment response in patients with Treatment Resistant Depression (TRD): A systematic review & meta-analysis

Multiple lines of evidence have implicated brain-derived neurotrophic factor (BDNF) in treatment-resistant depression (TRD). The aim of this synthesis was to determine the impact of TRD treatments on peripheral BDNF levels, and ascertain whether these changes are associated with antidepressant effects. Thirty-six articles involving 1198 patients with TRD were included herein. Electroconvulsive therapy (ECT), ketamine, and repetitive transcranial magnetic stimulation (rTMS) were the most common TRD treatments investigated. Serum BDNF levels significantly increased in six, two, four and one studies following ECT, ketamine, rTMS and atypical antipsychotics, respectively. The estimated mean baseline serum BDNF concentration in TRD patients ± 95% CI was 15.5 ± 4.34 ng/mL. Peripheral BDNF levels significantly increased overall (Hedges' g ± 95% CI = 0.336 ± 0.302; p < 0.05), but no association with depressive symptoms was found (p ≥ 0.05). These results demonstrate that peripheral measurements of total BDNF (i.e., mature and percursor forms of BDNF) are inadequate predictors of treatment response in TRD patients, and other considerations suggest that this would still apply to separable measurements of mature BDNF and its precursor.

Antidepressants Promote and Prevent Cancers

The review states that antidepressants (ADs) increase brain-derived neurotrophic factor (BDNF) transmission concomitantly in the brain and the blood: ADs increasing BDNF synthesis in specific areas of the central nervous system (CNS) could presumably affect megakaryocyte's production of platelets. ADs increase BDNF levels in the CNS and improve mood. In the blood, ADs increase BDNF release from platelets. The hypothesis presented here is that the release of BDNF from platelets contributes to the ADs effects on neurogenesis and on tumor growth in the cancer disease. Oncological studies indicate that chemicals ADs exert an aggravating effect on the cancer disease, possibly by promoting proplatelets formation and enhancing BDNF release from platelets in the tumor.

Brain-derived neurotrophic factor blood levels after electroconvulsive therapy in patients with major depressive disorder: A systematic review and meta-analysis

Some evidence pointed out that Electro-Convulsive Treatment (ECT) could increase the level of brain-derived neurotrophic factor (BDNF) in depressive patients. However, there are some disagreements. The purpose of the study is through a systematic review and meta-analysis to evaluate BDNF levels after ECT in patients with Major depressive disorder. Two independent researchers searched of published articles in the databases of Cochrane Library, PubMed, MEDLINE, EMBASE and WanFang Data, from January 1990 to March 2019. The following key words were used: "depression" or "depressive disorder", "major depressive disorder", "unipolar depression", "brain-derived neurotrophic factor" or "BDNF", and "electroconvulsive" or "ECT". A total of 22 studies met the inclusion criteria of the meta-analysis and included into our analysis. BDNF levels were increased among patients with MDD after ECT (P = 0.000) in plasma samples. The standardized mean difference (SMD) was 0.695 (95 % CI: 0.402-0.988). We also found BDNF levels increased on one week and one month after finishing ECT (SMD = 0.491, 95 %CI: 0.150,0.833, P = 0.005; and SMD = 0.812, 95 %CI: 0.326,1.298, P = 0.001, respectively). Our findings suggest that BDNF levels may increase after ECT and may possibly be used as an indicator of treatment response after one or more weeks of ECT in patients with depression. However, additional investigation of BDNF levels with different ECT durations are needed in responders and non-responders.

[Exercise for depression treatment. Exercise modalities and types]

The risk of metabolic disorders, including type 2 diabetes and cardiovascular diseases, is increased in depression, there is a decrease in life expectancy by 8-10 years. Pharmacotherapy is the first-line method in the treatment of depression. However, pharmaceutical-related side-effects and resistance to antidepressant pharmacotherapy create serious problems in treatment. Regular exercise not only weakens the symptoms of depression, increases aerobic capacity and muscle strength, but also has a positive effect on comorbid diseases. The purpose of this review is to answer the question, on which parameters of exercise the antidepressant effect depends. The review highlights the results of clinical studies of different types of exercises, intensities and modalities for the treatment of depression over the past 10 years. Because of the contradictory results of the studies, it is impossible to make final conclusions regarding the parameters of exercise. It is possible to say with high probability that in the treatment of depression, moderate and intense aerobic exercises with elements of strength exercises and a variety of coordination exercises more often lead to a positive effect than monotonous exercises with low intensity. It is possible that regular patient adherence to the prescribed exercise regimen is more important than the specific exercise type.

Beneficial Effects of Exercise Pretreatment in a Sporadic Alzheimer's Rat Model

PURPOSE

This study aimed to examine the effects of swimming exercise pretreatment on a streptozotocin (STZ)-induced sporadic Alzheimer's disease (AD) rat model and provide an initial understanding of related molecular mechanisms.

METHODS

Male 2.5-month-old Sprague-Dawley rats were divided into the following four groups: (a) control, (b) swim + vehicle, (c) STZ without swim, and (d) swim + STZ. The Barnes maze task and novel object recognition test were used to measure hippocampus-dependent spatial learning and working memory, respectively. Immunofluorescence staining, Western blot analysis, enzyme-linked immunosorbent assay (ELISA) analysis, and related assay kits were used to assess synaptic proteins, inflammatory cytokines, total antioxidant capacity, antioxidant enzymes, amyloid-beta production, and tau hyperphosphorylation.

RESULTS

Behavioral tests revealed that exercise pretreatment could significantly inhibit STZ-induced cognitive dysfunction (P < 0.05). STZ animals displayed significant loss of presynaptic/postsynaptic markers in the hippocampal CA1 that was reversed by exercise pretreatment (P < 0.05). STZ rats also displayed increased reactive gliosis, release of proinflammatory cytokines, and oxidative damage, effects attenuated by preexercise (P < 0.05, between-treatment changes). Likewise, preexercise significantly induced protein expression (P < 0.001) and DNA-binding activity (P = 0.015) of Nrf2 and downstream antioxidant gene expression in the hippocampal CA1 region (P < 0.05). STZ rats had increased levels of amyloid-beta (1-42) and tau hyperphosphorylation that were significantly ameliorated by exercise (P < 0.05). Histological studies showed that exercise imparted substantial neuroprotection (P < 0.001), suppressing neuronal apoptosis-like cell death in the hippocampal CA1 compared with the STZ control group (P < 0.001).

CONCLUSIONS

Exercise pretraining exerts multifactorial benefits on AD that support its use as a promising new therapeutic option for prevention of neurodegeneration in the elderly and/or AD population.

Plasma levels of brain-derived neurotrophic factor in patients with Parkinson disease: A systematic review and meta-analysis

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is an abundant neurotrophin in the adult brain. Serum BDNF levels might be used as a proxy for its central expression. Considering conflicting reports, we aimed to answer "How do serum/CSF levels of BDNF change in patients with PD?".

METHODS

We conducted a comprehensive search in MEDLINE, EMBASE and SCOPUS databases including 12 eligible studies. Five studies compared BDNF in serum of PD patients versus healthy controls (HC) and 3 studies provided BDNF levels in sera of non-depressed and depressed PD patients (NDPD and DPD). Review Manager and Software version 3.0 were used for meta-analysis and meta-regressions. Mean difference (MD) was used for measurement of effect size.

RESULTS

PD patients had reduced serum BDNF levels compared to HC (MD = -2.99 ng/mL). Serum BDNF was highest in DPD patients compared to HC (MD = -4.83 ng/mL), with no difference between DPD and NDPD patients in serum BDNF levels. Among co-variates that were eligible for meta-regression, age, sex, and Hoehn and Yahr (H&Y) motor stage had significant positive associations with the effect size in the difference of serum BDNF between patients and HC.

CONCLUSIONS

PD patients had reduced serum BDNF levels compared to HC, regardless of presence of co-morbid depression. PD is at least equally effective in reducing serum BDNF levels as depression. Motor progression predicts serum BDNF downregulation in PD. Acute exercise improves motor function and depressive symptoms in PD probably via BDNF upregulation. The paradoxical rise in serum BDNF in advance PD is probably compensatory in nature.

Scientific rigor and credibility in the nutrition research landscape

Scientific progress depends on the quality and credibility of research methods. As discourse on rigor, transparency, and reproducibility joins the cacophony of nutrition information and misinformation in mass media, buttressing the real and perceived reliability of nutrition science is more important than ever. This broad topic was the focus of a 2016 plenary session, "Scientific Rigor and Competing Interests in the Nutrition Research Landscape." This article summarizes and expands on this session in an effort to increase understanding and dialogue with regard to factors that limit the real and perceived reliability of nutrition science and steps that can be taken to mitigate those factors. The end goal is to both earn and merit greater trust in nutrition science by both the scientific community and the general public. The authors offer suggestions in each of the domains of education and training, communications, research conduct, and procedures and policies to help achieve this goal. The authors emphasize the need for adequate funding to support these efforts toward greater rigor and transparency, which will be resource demanding and may require either increased research funding or the recognition that a greater proportion of research funding may need to be allocated to these tasks.

Neurobiological mechanisms of exercise and psychotherapy in depression: The SPeED study-Rationale, design, and methodological issues

BACKGROUND/AIMS

Even though cognitive behavioral therapy has become a relatively effective treatment for major depressive disorder and cognitive behavioral therapy-related changes of dysfunctional neural activations were shown in recent studies, remission rates still remain at an insufficient level. Therefore, the implementation of effective augmentation strategies is needed. In recent meta-analyses, exercise therapy (especially endurance exercise) was reported to be an effective intervention in major depressive disorder. Despite these findings, underlying mechanisms of the antidepressant effect of exercise especially in combination with cognitive behavioral therapy have rarely been studied to date and an investigation of its neural underpinnings is lacking. A better understanding of the psychological and neural mechanisms of exercise and cognitive behavioral therapy would be important for developing optimal treatment strategies in depression. The SPeED study (Sport/Exercise Therapy and Psychotherapy-evaluating treatment Effects in Depressive patients) is a randomized controlled trial to investigate underlying physiological, neurobiological, and psychological mechanisms of the augmentation of cognitive behavioral therapy with endurance exercise. It is investigated if a preceding endurance exercise program will enhance the effect of a subsequent cognitive behavioral therapy.

METHODS

This study will include 105 patients diagnosed with a mild or moderate depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). The participants are randomized into one of three groups: a high-intensive or a low-intensive endurance exercise group or a waiting list control group. After the exercise program/waiting period, all patients receive an outpatient cognitive behavioral therapy treatment according to a standardized therapy manual. At four measurement points, major depressive disorder symptoms (Beck Depression Inventory, Hamilton Rating Scale for Depression), (neuro)biological measures (neural activations during working memory, monetary incentive delay task, and emotion regulation, as well as cortisol levels and brain-derived neurotrophic factor), neuropsychological test performance, and questionnaires (psychological needs, self-efficacy, and quality of life) are assessed.

RESULTS

In this article, we report the design of the SPeED study and refer to important methodological issues such as including both high- and low-intensity endurance exercise groups to allow the investigation of dose-response effects and physiological components of the therapy effects.

CONCLUSION

The main aims of this research project are to study effects of endurance exercise and cognitive behavioral therapy on depressive symptoms and to investigate underlying physiological and neurobiological mechanisms of these effects. Results may provide important implications for the development of effective treatment strategies in major depressive disorder, specifically concerning the augmentation of cognitive behavioral therapy by endurance exercise.

Effect of Physical Exercise and Acute Escitalopram on the Excitability of Brain Monoamine Neurons: In Vivo Electrophysiological Study in Rats

Background

The antidepressant effect of physical exercise has been reported in several clinical and animal studies. Since serotonin, norepinephrine, and dopamine play a central role in depression, it is possible that the beneficial effects of physical exercise are mediated via monoamine pathways. This study investigates the effects of voluntary wheel running on the excitability of monoamine neurons.

Materials and Methods

Male Sprague-Dawley rats were used in the study. Voluntary wheel running (VWR) rats were housed in individual cages with free access to a running wheel, while control animals were housed in standard laboratory cages. After three weeks, the rats were anesthetized, and in vivo electrophysiological recordings were taken from dorsal raphe nucleus serotonin neurons, locus coeruleus norepinephrine neurons, and ventral tegmental dopamine neurons.

Results

VWR stimulated activity in serotonin, but not in norepinephrine or dopamine neurons. Subsequently, acute administration of the selective serotonin reuptake inhibitor escitalopram in control rats led to complete suppression of serotonin neurons; this suppression was reversed by subsequent administration of selective antagonist of serotonin-1A receptors, WAY100135. Escitalopram induced only partial inhibition of serotonin neurons in the VWR rats while WAY100135 increased the firing activity of serotonin neurons above the baseline value.

Conclusions

The beneficial effect of physical exercise on mood is mediated, at least in part, via activation of serotonin neurons. Physical exercise can potentiate the response to selective serotonin reuptake inhibitors by increasing the basal firing activity and diminishing selective serotonin reuptake inhibitor-induced inhibition of serotonin neurons.

The effect of acute exercise on blood concentrations of brain-derived neurotrophic factor in healthy adults: a meta-analysis

It has been hypothesized that one mechanism through which physical activity provides benefits to cognition and mood is via increasing brain-derived neurotrophic factor (BDNF) concentrations. Some studies have reported immediate benefits to mood and various cognitive domains after a single session of exercise. This meta-analysis sought to determine the effect of a single exercise session on concentrations of BDNF in peripheral blood, in order to evaluate the potential role of BDNF in mediating the beneficial effects of exercise on brain health. MEDLINE, Embase, PsycINFO, SPORTDiscus, Rehabilitation & Sports Medicine Source, and CINAHL databases were searched for original, peer-reviewed reports of peripheral blood BDNF concentrations before and after acute exercise interventions. Risk of bias within studies was assessed using standardized criteria. Standardized mean differences (SMDs) were generated from random effects models. Risk of publication bias was assessed using a funnel plot and Egger's test. Potential sources of heterogeneity were explored in subgroup analyses. In 55 studies that met inclusion criteria, concentrations of peripheral blood BDNF were higher after exercise (SMD = 0.59, 95% CI: 0.46-0.72, P < 0.001). In meta-regression analysis, greater duration of exercise was associated with greater increases in BDNF. Subgroup analyses revealed an effect in males but not in females, and a greater BDNF increase in plasma than serum. Acute exercise increased BDNF concentrations in the peripheral blood of healthy adults. This effect was influenced by exercise duration and may be different across genders.

Exercise increases serum brain-derived neurotrophic factor in patients with major depressive disorder

BACKGROUND

Brain derived neurotrophic factor (BDNF) has been implicated in the pathogenesis of major depressive disorder (MDD). Existing data on exercise treatment in people with MDD are inconsistent concerning the effect of exercise on BDNF pointing either to increased or unaltered BDNF concentrations. However, studies in non-depressed persons demonstrated a significant effect on resting peripheral BDNF concentrations in aerobic training interventions. Given the lack of clarity mentioned above, the current study aimed at examining the effect of adjunctive exercise on serum BDNF levels in guideline based treated patients with MDD.

METHODS

42 depressed inpatients were included, and randomized either to a 6 week structured and supervised exercise intervention plus treatment as usual (EXERCISE, n=22), or to treatment as usual (TAU, n=20). BDNF serum concentrations were assessed before and after the intervention in both study groups with established immunoassays.

RESULTS

Serum BDNF slightly decreased in the TAU group, whilst there was an increase in BDNF levels in the exercise group. There was a significant time x group effect concerning sBDNF (p=0.030) with repeated ANOVA measures with age and BMI as covariates, suggesting an increase in BDNF concentrations in the EXERCISE group compared to TAU.

LIMITATIONS

Though there was no statistic difference in the antidepressant medication between EXERCISE and TAU potential interactions between exercise and medication on the effects of exercise in BDNF cannot be excluded. Gender was not considered as a covariate in ANOVA due to the small number of objects.

CONCLUSIONS

Exercise training given as adjunct to standard guideline based treatment appears to have additional effects on BDNF serum concentrations in people with MDD. Our results add further evidence to the beneficial effects of exercise in the treatment of MDD.

Challenges Establishing the Efficacy of Exercise as an Antidepressant Treatment: A Systematic Review and Meta-Analysis of Control Group Responses in Exercise Randomised Controlled Trials

BACKGROUND

Whilst previous meta-analyses have demonstrated that control group responses (CGRs) can negatively influence antidepressant efficacy, no such meta-analysis exists in exercise randomised controlled trials (RCTs).

OBJECTIVE

The aim of this study was to conduct a systematic review and meta-analysis investigating CGRs and predictors in control groups of exercise RCTs among adults with depression.

METHODS

Three authors acquired RCTs from a previous Cochrane review (2013) and conducted updated searches of major databases from January 2013 to August 2015. We included exercise RCTs that (1) involved adults with major depressive disorder (MDD) or depressive symptoms; (2) measured depressive symptoms pre- and post-intervention using a validated measure [e.g. Hamilton Depression Scale (HAM-D)]; and (3) included a non-active control group. A random effects meta-analysis calculating the standardised mean difference (SMD) together with 95 % confidence intervals (CIs) was employed to determine CGR.

RESULTS

Across 41 studies, 1122 adults with depression were included [mean (SD) age 50 (18) years, 63 % female]. A large CGR of improved depressive symptoms was evident across all studies (SMD -0.920, 95 % CI -1.11 to -0.729). CGRs were elevated across all subgroup analyses, including high quality studies (n = 11, SMD -1.430, 95 % CI -1.771 to -1.090) and MDD participants (n = 18, SMD -1.248, 95 % CI = -1.585 to -0.911). The CGR equated to an improvement of -7.5 points on the HAM-D (95 % CI -10.30 to -4.89). In MDD participants, increasing age moderated a smaller CGR, while the percentage of drop-outs, baseline depressive symptoms and a longer control group duration moderated a larger CGR (i.e. improvement) (p < 0.05).

CONCLUSION

In order to demonstrate effectiveness, exercise has to overcome a powerful CGR of approximately double that reported for antidepressant RCTS.

A critical review of exercise as a treatment for clinically depressed adults: time to get pragmatic

OBJECTIVE

Although considerable evidence supports the efficacy of exercise as an antidepressant treatment, critical reviews informing routine practice and future research directions are scarce.

METHODS

We critically reviewed exercise studies for clinically depressed adults, focussing on the PICOS criteria referred to participants, interventions, comparisons, outcomes, and study designs.

RESULTS

Most studies have not screened their samples for symptom heterogeneity. Also, they have employed heterogeneous exercise interventions and control groups that may lead to an underestimation of the benefits of exercise. In addition, pragmatic trials allowing scalable replication and implementation in routine practice are scarce. Future studies, can consider the research domain criteria as a diagnostic framework, and conduct moderator analyses to identify depressed subgroups with symptomatology and biopsychosocial characteristics associated with differential responses to exercise interventions. The search for biomarkers of the antidepressant responses to exercise should be prioritised. Further, non-physically active comparison groups should be used to minimise treatment cross-overs and thus the underestimation of the effects of exercise interventions. Finally, the use of outcome measures that maintain their validity at low and moderate levels of symptom severity and the development of trials with a pragmatic design are essential.

CONCLUSION

The current evidence base is fraught with methodological considerations that need to be taken into account in order to increase further our understanding on the impact of exercise as medicine in depression. Future research should include moderator analyses, incorporate biomarker assays, use appropriate control and comparison groups, assess outcomes with psychometrically sensitive measures, and prioritise pragmatic trials towards transition to routine practice.

Adjuvant thiamine improved standard treatment in patients with major depressive disorder: results from a randomized, double-blind, and placebo-controlled clinical trial

Given that antidepressants (ADs) work slowly, there is interest in means to accelerate their therapeutic effect and to reduce side effects. In this regard, thiamine (vitamin B₁) is attracting growing interest. Thiamine is an essential nutrient, while thiamine deficiency leads to a broad variety of disorders including irritability and symptoms of depression. Here, we tested the hypothesis that adjuvant thiamine would reduce depression, compared to placebo. A total of 51 inpatients (mean age: 35.2 years; 53 % females) with MDD (Hamilton Depression Rating Scale score (HDRS) at baseline: >24) took part in the study. A standardized treatment with SSRI was introduced and kept at therapeutic levels throughout the study. Patients were randomly assigned either to the thiamine or the placebo condition. Experts rated (HDRS) symptoms of depression at baseline, and after 3, 6, and 12 weeks (end of the study). Between baseline and the end of the study, depression had reduced in both groups. Compared to placebo, adjuvant thiamine improved symptoms of depression after 6 week of treatment, and improvements remained fairly stable until the end of the study, though mean differences at week 12 were not statistically significant anymore. No adverse side effects were reported in either group. Results suggest that among younger patients with MDD adjuvant thiamine alleviated symptoms of depression faster compared to placebo. Importantly, improvements were observed within 6 weeks of initiation of treatment. Thus, thiamine might have the potential to counteract the time lag in the antidepressant effects of ADs.

Exercise as a treatment for depression: A meta-analysis

BACKGROUND

This meta-analysis of randomized controlled trials (RCTs) examines the efficacy of physical exercise as treatment for unipolar depression, both as an independent intervention and as an adjunct intervention to antidepressant medication.

METHODS

We searched PsycINFO, EMBASE, MEDLINE, CENTRAL, and Sports Discus for articles published until November 2014. Effect sizes were computed with random effects models. The main outcome was reduction in depressive symptoms or remission.

RESULTS

A total of 23 RCTs and 977 participants were included. Physical exercise had a moderate to large significant effect on depression compared to control conditions (g=-0.68), but the effect was small and not significant at follow-up (g=-0.22). Exercise compared to no intervention yielded a large and significant effect size (g=-1.24), and exercise had a moderate and significant effect compared to usual care (g=-0.48). The effects of exercise when compared to psychological treatments or antidepressant medication were small and not significant (g=-0.22 and g=-0.08, respectively). Exercise as an adjunct to antidepressant medication yielded a moderate effect (g=-0.50) that trended toward significance.

LIMITATIONS

Use of the arms with the largest clinical effect instead of largest dose may have overestimated the effect of exercise.

CONCLUSIONS

Physical exercise is an effective intervention for depression. It also could be a viable adjunct treatment in combination with antidepressants.

Electroconvulsive therapy (ECT) and aerobic exercise training (AET) increased plasma BDNF and ameliorated depressive symptoms in patients suffering from major depressive disorder

BACKGROUND

To treat patients suffering from major depressive disorder (MDD), research has focused on electroconvulsive therapy (ECT) and aerobic exercise training (AET). Brain derived neurotrophic factor (BDNF) seems to be key in MDD. The aims of the present study were therefore two-fold, to investigate in a three-arm interventional study the differential effects of ECT, ECT plus AET, and AET alone in patients suffering from TR-MDD on 1. depressive symptoms and 2. plasma BDNF (pBDNF).

METHODS

60 patients with MDD (mean age: 31 years; 31.6% female patients) were randomly assigned either to the ECT, ECT + AET, or AET condition. The AET condition consisted of treadmill exercise for 45 min, three times a week. Both depression severity and pBDNF levels were assessed at baseline and 4 weeks later. All patients were further treated with an SSRI standard medication.

RESULTS

pBDNF levels increased over time in all three study conditions, though, highest increase was observed in the ECT + EAT condition, and lowest increase was observed in the AET condition. Depressive symptoms decreased in all three conditions over time, though, strongest decrease was observed in the ECT + AET condition. The combination of ECT + AET led to significantly greater remission rates than in either the ECT or AET alone conditions. BDNF levels were not associated with symptoms of depression.

CONCLUSIONS

The pattern of results suggests that ECT, AET and particularly their combination are promising directions for the treatment of patients suffering from MDD, and that it remains unclear to what extent pBDNF is key and a reliable biomarker for MDD.

Dropout from exercise randomized controlled trials among people with depression: A meta-analysis and meta regression

OBJECTIVE

Exercise has established efficacy in improving depressive symptoms. Dropouts from randomized controlled trials (RCT's) pose a threat to the validity of this evidence base, with dropout rates varying across studies. We conducted a systematic review and meta-analysis to investigate the prevalence and predictors of dropout rates among adults with depression participating in exercise RCT's.

METHOD

Three authors identified RCT's from a recent Cochrane review and conducted updated searches of major electronic databases from 01/2013 to 08/2015. We included RCT's of exercise interventions in people with depression (including major depressive disorder (MDD) and depressive symptoms) that reported dropout rates. A random effects meta-analysis and meta regression were conducted.

RESULTS

Overall, 40 RCT's were included reporting dropout rates across 52 exercise interventions including 1720 people with depression (49.1 years (range=19-76 years), 72% female (range=0-100)). The trim and fill adjusted prevalence of dropout across all studies was 18.1% (95%CI=15.0-21.8%) and 17.2% (95%CI=13.5-21.7, N=31) in MDD only. In MDD participants, higher baseline depressive symptoms (β=0.0409, 95%CI=0.0809-0.0009, P=0.04) predicted greater dropout, whilst supervised interventions delivered by physiotherapists (β=-1.2029, 95%CI=-2.0967 to -0.3091, p=0.008) and exercise physiologists (β=-1.3396, 95%CI=-2.4478 to -0.2313, p=0.01) predicted lower dropout. A comparative meta-analysis (N=29) established dropout was lower in exercise than control conditions (OR=0.642, 95%CI=0.43-0.95, p=0.02).

CONCLUSIONS

Exercise is well tolerated by people with depression and drop out in RCT's is lower than control conditions. Thus, exercise is a feasible treatment, in particular when delivered by healthcare professionals with specific training in exercise prescription.

The Therapeutic Potential of Exercise to Improve Mood, Cognition, and Sleep in Parkinson's Disease

In addition to the classic motor symptoms, Parkinson's disease (PD) is associated with a variety of nonmotor symptoms that significantly reduce quality of life, even in the early stages of the disease. There is an urgent need to develop evidence-based treatments for these symptoms, which include mood disturbances, cognitive dysfunction, and sleep disruption. We focus here on exercise interventions, which have been used to improve mood, cognition, and sleep in healthy older adults and clinical populations, but to date have primarily targeted motor symptoms in PD. We synthesize the existing literature on the benefits of aerobic exercise and strength training on mood, sleep, and cognition as demonstrated in healthy older adults and adults with PD, and suggest that these types of exercise offer a feasible and promising adjunct treatment for mood, cognition, and sleep difficulties in PD. Across stages of the disease, exercise interventions represent a treatment strategy with the unique ability to improve a range of nonmotor symptoms while also alleviating the classic motor symptoms of the disease. Future research in PD should include nonmotor outcomes in exercise trials with the goal of developing evidence-based exercise interventions as a safe, broad-spectrum treatment approach to improve mood, cognition, and sleep for individuals with PD.

Neurobiological effects of exercise on major depressive disorder: A systematic review

Exercise displays promise as an efficacious treatment for people with depression. However, no systematic review has evaluated the neurobiological effects of exercise among people with major depressive disorder (MDD). The aim of this article was to systematically review the acute and chronic biological responses to exercise in people with MDD. Two authors conducted searches using Medline (PubMed), EMBASE and PsycINFO. From the searches, twenty studies were included within the review, representing 1353 people with MDD. The results demonstrate that a single bout of exercise increases atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), copepetin and growth hormone among people with MDD. Exercise also potentially promotes long-term adaptations of copeptin, thiobarbituric acid reactive species (TBARS) and total mean frequency (TMF). However, there is limited evidence that exercise promotes adaptations on neurogenesis, inflammation biomarkers and brain structure. Associations between depressive symptoms improvement and hippocampus volume and IL-1β were found. Nevertheless, the paucity of studies and limitations presented within, precludes a more definitive conclusion of the underlying neurobiological explanation for the antidepressant effect of exercise in people with MDD. Further trials should utilize appropriate assessments of neurobiological markers in order to build upon the results of our review and further clarify the potential mechanisms associated with the antidepressant effects of exercise.

Feasibility of an Exercise Program for Older Depressive Inpatients

Abstract. Twelve older inpatients (M age = 66.8) with Major Depressive Disorder (MDD) participated in this controlled pilot trial either in a physical exercise group (PEG; n = 6; aerobic, strength, and coordination exercises) or an active control group (ACG; n = 6; relaxation exercises) twice a week for four weeks. While depressive symptoms decreased in both groups, reduction of symptoms was significantly larger in the PEG. However, the PEG had higher BDI scores compared to the ACG at pretest. Neurocognitive functioning and brain-derived neurotrophic factor (BDNF) concentration did not change significantly. A four-week exercise program may be a feasible adjunct therapy in older MDD patients but the efficacy of the program needs to be proven with larger samples.

Using Exercise to Fight Depression in Older Adults

Abstract. Depression is the most prevalent psychiatric disorder in the general population. Despite a large demand for efficient treatment options, the majority of older depressed adults does not receive adequate treatment: Additional low-threshold treatments are needed for this age group. Over the past two decades, a growing number of randomized controlled trials (RCT) have been conducted, testing the efficacy of physical exercise in the alleviation of depression in older adults. This meta-analysis systematically reviews and evaluates these studies; some subanalyses testing specific effects of different types of exercise and settings are also performed. In order to be included, exercise programs of the RCTs had to fulfill the criteria of exercise according to the American College of Sports Medicine, including a sample mean age of 60 or above and an increased level of depressive symptoms. Eighteen trials with 1,063 participants fulfilled our inclusion criteria. A comparison of the posttreatment depression scores between the exercise and control groups revealed a moderate effect size in favor of the exercise groups (standardized mean difference (SMD) of –0.68, p < .001). The effect was comparable to the results achieved when only the eleven trials with low risk of bias were included (SMD = –0.63, p < .001). The subanalyses showed significant effects for all types of exercise and for supervised interventions. The results of this meta-analysis suggest that physical exercise may serve as a feasible, additional intervention to fight depression in older adults. However, because of small sample sizes of the majority of individual trials and high statistical heterogeneity, results must be interpreted carefully.

Serum BDNF as a peripheral biomarker of treatment-resistant depression and the rapid antidepressant response: A comparison of ketamine and ECT

BACKGROUND

Ketamine is associated with rapid antidepressant efficacy but the biological mechanisms underpinning this effect are unclear. Serum brain-derived neurotrophic factor (sBDNF) is a potential circulating biomarker of treatment-resistant depression (TRD) and ketamine response but it is unclear if this is a common target of both ketamine and electroconvulsive therapy (ECT), the current gold standard for TRD. Moreover, the impact of multiple ketamine infusions on sBDNF has not yet been established.

METHODS

Thirty five TRD patients with a current DSM-IV diagnosis of recurrent depressive disorder received up to 12 ECT sessions (N=17) or up to three intravenous infusions of low-dose (0.5mg/kg) ketamine (N=18). Blood samples were taken over the course of the study for assessment of sBDNF. Symptom severity and response were monitored using the 17-item Hamilton Depression Rating Scale (HDRS). sBDNF was assessed in 20 healthy controls to allow comparison with TRD patients.

RESULTS

As expected, sBDNF was lower in TRD patients at baseline compared to healthy controls. Ketamine and ECT treatment were both associated with significant reductions in depressive symptoms. However, sBDNF was significantly elevated only at one week following the first ketamine infusion in those classified as responders one week later. sBDNF was not elevated following subsequent infusions. ECT reduced depressive symptoms, as expected, but was not associated with an enhancement in BDNF.

LIMITATIONS

Patients continued with their psychotropic medications throughout this trial.

CONCLUSIONS

SBDNF normalisation does not appear to be a prerequisite for symptomatic improvement in TRD following ketamine or ECT treatment.

7,8-Dihydroxyflavone reduces sleep during dark phase and suppresses orexin A but not orexin B in mice

Brain-derived neurotrophic factor (BDNF) binds to Tropomyosin-receptor-kinase B (TrkB) receptors that regulate synaptic strength and plasticity in the mammalian nervous system. 7,8-Dihydroxyflavone (DHF) is a recently identified small molecule Trk B agonist that has been reported to ameliorate depression, attenuate the fear response, improve memory consolidation, and exert neuroprotective effects. Poor and disturbed sleep remains a symptom of major depressive disorder and most current antidepressants affect sleep. Therefore, we conducted sleep/wake recordings and concomitant measurement of brain orexins, endogenous peptides that suppress sleep, in mice for this study. Baseline polysomnograph recording was performed for 24 h followed by treatment with either 5 mg/kg of DHF or vehicle at the beginning of the dark phase. Animals were sacrificed the following day, one hour after the final treatment with DHF. Orexin A and B were quantified using ELISA and radioimmunoassay, respectively. Total sleep was significantly decreased in the DHF group, 4 h after drug administration in the dark phase, when compared with vehicle-treated animals. This difference was due to a significant decrease of non-rapid eye movement sleep, but not rapid eye movement sleep. DHF increased power of alpha and sigma bands but suppressed power of gamma band during sleep in dark phase. Interestingly, hypothalamic levels of orexin A were also significantly decreased in the DHF group (97 pg/mg) when compared with the vehicle-treated group (132 pg/mg). However, no significant differences of orexin B were observed between groups. Additionally, no change was found in immobility tests.

BDNF and COX-2 participate in anti-depressive mechanisms of catalpol in rats undergoing chronic unpredictable mild stress

Catalpol, a major compound in Rehmannia glutinosa with both medicinal and nutritional values, has been previously confirmed to shorten the duration of immobility in mice exposed to tail suspension and forced swimming tests. This study attempted to examine the anti-depressive mechanisms of catalpol in rats undergoing chronic unpredictable mild stress (CUMS) by involving brain-derived neurotrophic factor (BDNF) and cyclooxygenase-2 (COX-2). CUMS-exposed rats were given catalpol daily (5, 10, and 20mg/kg, ig) or a reference drug, fluoxetine hydrochloride (FH, 10mg/kg, ig), at 5 weeks after starting the CUMS procedure. Sucrose preference test was performed to observe depression-like behavior, and serum and brain tissues were used for neurochemical and fluorescent quantitative reverse transcription PCR analysis. CUMS induced depression-like behavior, whereas catalpol and FH administration attenuated this symptom. Moreover, CUMS caused excessively elevated levels of serum corticosterone, an index of hypothalamic-pituitary-adrenal (HPA) axis hyperactivation, in a manner attenuated by catalpol and FH administration. Catalpol administration also further decreased BDNF activities, downregulated the mRNA expression of BDNF and tropomyosin-related kinase B (TrkB), and reversed the excessive elevation in the activities and mRNA expression levels of COX-2 and prostaglandin E2 (PGE2) in the hippocampus and frontal cortex of rats undergoing CUMS. Results indicate that catalpol can ameliorate CUMS-induced depression-like behavior, and suggest its mechanisms may partially be ascribed to restoring HPA axis dysfunctions, upregulating BDNF expression and its cognate receptor TrkB, and downregulating COX-2 expression, thereby reducing PGE2 levels in the brain.

Optimizing the Exercise Prescription for Depression: The Search for Biomarkers of Response

There is growing support for the efficacy of exercise interventions for the treatment of individuals who present with mild-to-moderate depression. The variability in treatment response across studies and individuals suggests that the efficacy of exercise for depression will be most optimal when prescribed to individuals who are most prone to respond. The present article reviews contemporary theoretical accounts and recent empirical data pointing to neuroinflammatory states and neurotrophin production as possible biomarkers of the antidepressant response to exercise. The larger exercise and depression literatures provide justification for elevated levels of pro-inflammatory cytokines and deficits in BDNF production as putative matching variables. Although there is some empirical support for these hypotheses, it is clear that this research warrants replication and extension. We offer a few suggestions for future research in this emerging area.

Serum brain-derived neurotrophic factor levels in relation to comorbid depression and cytokine levels in Nepalese men with alcohol-use disorders

Neurodegenerative and inflammatory processes are involved separately in major depression (MD) and alcohol-use disorders (AUD). Little is known about the nature of this relationship in the context of comorbid AUD and depression disorders. In this study, we determined brain-derived neurotrophic factor (BDNF) serum levels in patients with AUD and tested whether BDNF levels were related to history of major depression, recent depressive symptoms, AUD severity, and TNF-α and IL-6 levels. Nepalese male AUD inpatients (N=152) abstinent from alcohol for an average of 34 days were administered structured interviews to assess depression symptoms and pattern and extent of alcohol use, and to generate research diagnoses for AUD and MD. AUD severity was assessed by scores on the Alcohol Use Disorder Identification Test. Serum BDNF and cytokines were measured using ELISA and multiplex technology, respectively. Although serum BDNF levels were unrelated to MD history, patients with recent depressive symptoms (n=42) had lower (mean±SD) BDNF serum levels compared to those without (n=110) (21.6±8.1 ng/mL vs. 26.0±9.6 ng/mL; p=0.010), and patients with higher AUD severity and binge-drinking patterns had higher mean serum BDNF levels compared to lower AUD severity and non-binging (25.9±9.7 ng/mL vs. 22.1±8.7 ng/mL; p=0.022 and 25.7±9.3 vs. 21.8±9.7 ng/mL; p=0.029, respectively). Positive correlations were present between BDNF and TNF-α (r=0.39, p<0.001) and IL-6 (r=0.2, p=0.027). In particular, TNF-α levels were predictive of BDNF levels after controlling for confounders (B=0.3 [95% CI=0.2-0.5], p<0.001). These findings show that in alcohol-using populations, peripheral BDNF levels are related to severity of AUD as well as presence of depressive symptoms. The significant associations between inflammatory and neurotrophic factors may have implications for neuroadaptive changes during recovery from AUD.

Electroconvulsive therapy improves clinical manifestations of treatment-resistant depression without changing serum BDNF levels

Electroconvulsive therapy (ECT) is effective in treatment-resistant depression (TRD). It may act through intracellular process modulation, but its exact mechanism is still unknown. Animal research supports a neurotrophic effect for ECT. We aimed to investigate the association between changes in serum brain-derived neurotrophic factor (sBDNF) levels and clinical improvement following ECT in patients with TRD. Twenty-one patients with TRD (2 men, 19 women; mean age, 63.5 years; S.D., 11.9) were assessed through the Hamilton Depression Rating Scale (HDRS), the Brief Psychiatric Rating Scale (BPRS), and the Clinical Global Impressions scale, Severity (CGIs) before and after a complete ECT cycle. At the same time-points, patients underwent blood withdrawal for measuring sBDNF levels. ECT significantly reduced HDRS, BPRS, and CGIS scores, but not sBDNF levels. No significant correlation was found between sBDNF changes, and each of HDRS, BPRS, and CGIs score changes. sBDNF levels in TRD patients were low both at baseline and post-ECT. Our results do not support that improvements in TRD following ECT are mediated through increases in sBDNF levels.

Prior regular exercise reverses the decreased effects of sleep deprivation on brain-derived neurotrophic factor levels in the hippocampus of ovariectomized female rats

Previous studies indicated that brain-derived neurotrophic factor (BDNF) is the main candidate to mediate the beneficial effects of exercise on cognitive function in sleep deprived male rats. In addition, our previous findings demonstrate that female rats are more vulnerable to the deleterious effects of sleep deprivation on cognitive performance and synaptic plasticity. Therefore, the current study was designed to investigate the effects of treadmill exercise and/or sleep deprivation (SD) on the levels of BDNF mRNA and protein in the hippocampus of female rats. Intact and ovariectomized (OVX) female Wistar rats were used in the present experiment. The exercise protocol was four weeks treadmill running and sleep deprivation was accomplished using the multiple platform method. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblot analysis were used to evaluate the level of BDNF mRNA and protein in the rat hippocampus respectively. Our results showed that protein and mRNA expression of BDNF was significantly (p<0.05) decreased after 72 h SD in OVX rats in compared with other groups. Furthermore, sleep deprived OVX rats under exercise conditions had a significant (p<0.05) up-regulation of the BDNF protein and mRNA in the hippocampus. These findings suggest that regular exercise can exert a protective effect against hippocampus-related functions and impairments induced by sleep deprivation probably by inducing BDNF expression.

In a randomized, double-blind clinical trial, adjuvant atorvastatin improved symptoms of depression and blood lipid values in patients suffering from severe major depressive disorder

BACKGROUND

The administration of statins seems to be a promising new avenue in the treatment of patients suffering from major depressive disorder (MDD), though patients suffering from severe MDD remain unstudied in this respect. The aim of the present study was therefore to investigate, in a randomized double-blind clinical trial, the influence of adjuvant atorvastatin on symptoms of depression in patients with MDD.

METHODS

A total of 60 patients suffering from MDD (mean age: 32.25 years; 53% males) received a standard medication of 40 mg/d citalopram. Next, patients were randomly assigned either to the atorvastatin group (20 mg/d) or to the placebo group. Blood lipid values were assessed at baseline and on completion of the study 12 weeks later. Experts rated depressive symptoms via Hamilton Depression Rating Scales (HDRS) at baseline and 3, 6 and 12 weeks later.

RESULTS

HDRS scores decreased over time; the significant Time by Group interaction showed that symptoms of depression decreased more in the atorvastatin than in the placebo group. Compared to the placebo group, in the atorvastatin group cholesterol, triglyceride, and Low Density Lipids (LDL) significantly decreased, and High Density Lipids (HDL) significantly increased over time. HDRS scores and blood lipid values were generally not associated.

CONCLUSIONS

The pattern of results suggests that adjuvant atorvastatin favorably influences symptoms of depression among patients with severe MDD. Given that after 12 weeks of monotherapy and adjuvant atorvastatin patients were still moderately to severely depressed, more powerful treatment algorithms such as augmentation and change of medication are highly recommended.