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BMJ (Clinical Research Ed.) Feb 2024To identify the optimal dose and modality of exercise for treating major depressive disorder, compared with psychotherapy, antidepressants, and control conditions. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To identify the optimal dose and modality of exercise for treating major depressive disorder, compared with psychotherapy, antidepressants, and control conditions.
DESIGN
Systematic review and network meta-analysis.
METHODS
Screening, data extraction, coding, and risk of bias assessment were performed independently and in duplicate. Bayesian arm based, multilevel network meta-analyses were performed for the primary analyses. Quality of the evidence for each arm was graded using the confidence in network meta-analysis (CINeMA) online tool.
DATA SOURCES
Cochrane Library, Medline, Embase, SPORTDiscus, and PsycINFO databases.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Any randomised trial with exercise arms for participants meeting clinical cut-offs for major depression.
RESULTS
218 unique studies with a total of 495 arms and 14 170 participants were included. Compared with active controls (eg, usual care, placebo tablet), moderate reductions in depression were found for walking or jogging (n=1210, κ=51, Hedges' g -0.62, 95% credible interval -0.80 to -0.45), yoga (n=1047, κ=33, g -0.55, -0.73 to -0.36), strength training (n=643, κ=22, g -0.49, -0.69 to -0.29), mixed aerobic exercises (n=1286, κ=51, g -0.43, -0.61 to -0.24), and tai chi or qigong (n=343, κ=12, g -0.42, -0.65 to -0.21). The effects of exercise were proportional to the intensity prescribed. Strength training and yoga appeared to be the most acceptable modalities. Results appeared robust to publication bias, but only one study met the Cochrane criteria for low risk of bias. As a result, confidence in accordance with CINeMA was low for walking or jogging and very low for other treatments.
CONCLUSIONS
Exercise is an effective treatment for depression, with walking or jogging, yoga, and strength training more effective than other exercises, particularly when intense. Yoga and strength training were well tolerated compared with other treatments. Exercise appeared equally effective for people with and without comorbidities and with different baseline levels of depression. To mitigate expectancy effects, future studies could aim to blind participants and staff. These forms of exercise could be considered alongside psychotherapy and antidepressants as core treatments for depression.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42018118040.
Topics: Humans; Network Meta-Analysis; Depression; Depressive Disorder, Major; Bayes Theorem; Exercise; Antidepressive Agents; Quality of Life; Randomized Controlled Trials as Topic
PubMed: 38355154
DOI: 10.1136/bmj-2023-075847 -
British Journal of Sports Medicine Aug 2023To estimate the efficacy of exercise on depressive symptoms compared with non-active control groups and to determine the moderating effects of exercise on depression and... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To estimate the efficacy of exercise on depressive symptoms compared with non-active control groups and to determine the moderating effects of exercise on depression and the presence of publication bias.
DESIGN
Systematic review and meta-analysis with meta-regression.
DATA SOURCES
The Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, Embase, SPORTDiscus, PsycINFO, Scopus and Web of Science were searched without language restrictions from inception to 13 September2022 (PROSPERO registration no CRD42020210651).
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Randomised controlled trials including participants aged 18 years or older with a diagnosis of major depressive disorder or those with depressive symptoms determined by validated screening measures scoring above the threshold value, investigating the effects of an exercise intervention (aerobic and/or resistance exercise) compared with a non-exercising control group.
RESULTS
Forty-one studies, comprising 2264 participants post intervention were included in the meta-analysis demonstrating large effects (standardised mean difference (SMD)=-0.946, 95% CI -1.18 to -0.71) favouring exercise interventions which corresponds to the number needed to treat (NNT)=2 (95% CI 1.68 to 2.59). Large effects were found in studies with individuals with major depressive disorder (SMD=-0.998, 95% CI -1.39 to -0.61, k=20), supervised exercise interventions (SMD=-1.026, 95% CI -1.28 to -0.77, k=40) and moderate effects when analyses were restricted to low risk of bias studies (SMD=-0.666, 95% CI -0.99 to -0.34, k=12, NNT=2.8 (95% CI 1.94 to 5.22)).
CONCLUSION
Exercise is efficacious in treating depression and depressive symptoms and should be offered as an evidence-based treatment option focusing on supervised and group exercise with moderate intensity and aerobic exercise regimes. The small sample sizes of many trials and high heterogeneity in methods should be considered when interpreting the results.
Topics: Humans; Depression; Depressive Disorder, Major; Exercise; Exercise Therapy
PubMed: 36731907
DOI: 10.1136/bjsports-2022-106282 -
Diabetes Care Sep 2023Depression is a common comorbidity of type 2 diabetes. We assessed the causal relationships and shared genetics between them.
OBJECTIVE
Depression is a common comorbidity of type 2 diabetes. We assessed the causal relationships and shared genetics between them.
RESEARCH DESIGN AND METHODS
We applied two-sample, bidirectional Mendelian randomization (MR) to assess causality between type 2 diabetes and depression. We investigated potential mediation using two-step MR. To identify shared genetics, we performed 1) genome-wide association studies (GWAS) separately and 2) multiphenotype GWAS (MP-GWAS) of type 2 diabetes (19,344 case subjects, 463,641 control subjects) and depression using major depressive disorder (MDD) (5,262 case subjects, 86,275 control subjects) and self-reported depressive symptoms (n = 153,079) in the UK Biobank. We analyzed expression quantitative trait locus (eQTL) data from public databases to identify target genes in relevant tissues.
RESULTS
MR demonstrated a significant causal effect of depression on type 2 diabetes (odds ratio 1.26 [95% CI 1.11-1.44], P = 5.46 × 10-4) but not in the reverse direction. Mediation analysis indicated that 36.5% (12.4-57.6%, P = 0.0499) of the effect from depression on type 2 diabetes was mediated by BMI. GWAS of type 2 diabetes and depressive symptoms did not identify shared loci. MP-GWAS identified seven shared loci mapped to TCF7L2, CDKAL1, IGF2BP2, SPRY2, CCND2-AS1, IRS1, CDKN2B-AS1. MDD has not brought any significant association in either GWAS or MP-GWAS. Most MP-GWAS loci had an eQTL, including single nucleotide polymorphisms implicating the cell cycle gene CCND2 in pancreatic islets and brain and the insulin signaling gene IRS1 in adipose tissue, suggesting a multitissue and pleiotropic underlying mechanism.
CONCLUSIONS
Our results highlight the importance to prevent type 2 diabetes at the onset of depressive symptoms and the need to maintain a healthy weight in the context of its effect on depression and type 2 diabetes comorbidity.
Topics: Humans; Genome-Wide Association Study; Diabetes Mellitus, Type 2; Depression; Depressive Disorder, Major; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide; Membrane Proteins; Intracellular Signaling Peptides and Proteins; RNA-Binding Proteins
PubMed: 37494602
DOI: 10.2337/dc22-2373 -
JAMA Psychiatry Aug 2023Cannabis use is increasing worldwide and is suspected to be associated with increased risk of psychiatric disorders; however, the association with affective disorders...
IMPORTANCE
Cannabis use is increasing worldwide and is suspected to be associated with increased risk of psychiatric disorders; however, the association with affective disorders has been insufficiently studied.
OBJECTIVE
To examine whether cannabis use disorder (CUD) is associated with an increased risk of psychotic and nonpsychotic unipolar depression and bipolar disorder and to compare associations of CUD with psychotic and nonpsychotic subtypes of these diagnoses.
DESIGN, SETTING, AND PARTICIPANTS
This prospective, population-based cohort study using Danish nationwide registers included all individuals born in Denmark before December 31, 2005, who were alive, aged at least 16 years, and living in Denmark between January 1, 1995, and December 31, 2021.
EXPOSURE
Register-based diagnosis of CUD.
MAIN OUTCOME AND MEASURES
The main outcome was register-based diagnosis of psychotic or nonpsychotic unipolar depression or bipolar disorder. Associations between CUD and subsequent affective disorders were estimated as hazard ratios (HRs) using Cox proportional hazards regression with time-varying information on CUD, adjusting for sex; alcohol use disorder; substance use disorder; having been born in Denmark; calendar year; parental educational level (highest attained); parental cannabis, alcohol, or substance use disorders; and parental affective disorders.
RESULTS
A total of 6 651 765 individuals (50.3% female) were followed up for 119 526 786 person-years. Cannabis use disorder was associated with an increased risk of unipolar depression (HR, 1.84; 95% CI, 1.78-1.90), psychotic unipolar depression (HR, 1.97; 95% CI, 1.73-2.25), and nonpsychotic unipolar depression (HR, 1.83; 95% CI, 1.77-1.89). Cannabis use was associated with an increased risk of bipolar disorder in men (HR, 2.96; 95% CI, 2.73-3.21) and women (HR, 2.54; 95% CI, 2.31-2.80), psychotic bipolar disorder (HR, 4.05; 95% CI, 3.52-4.65), and nonpsychotic bipolar disorder in men (HR, 2.96; 95% CI, 2.73-3.21) and women (HR, 2.60; 95% CI, 2.36-2.85). Cannabis use disorder was associated with higher risk for psychotic than nonpsychotic subtypes of bipolar disorder (relative HR, 1.48; 95% CI, 1.21-1.81) but not unipolar depression (relative HR, 1.08; 95% CI, 0.92-1.27).
CONCLUSIONS AND RELEVANCE
This population-based cohort study found that CUD was associated with an increased risk of psychotic and nonpsychotic bipolar disorder and unipolar depression. These findings may inform policies regarding the legal status and control of cannabis use.
Topics: Male; Female; Humans; Bipolar Disorder; Depression; Cohort Studies; Prospective Studies; Marijuana Abuse; Substance-Related Disorders; Depressive Disorder, Major
PubMed: 37223912
DOI: 10.1001/jamapsychiatry.2023.1256 -
BMC Medicine Sep 2023Major depressive disorder (MDD) has a significant impact on global burden of disease. Complications in clinical management can occur when response to pharmacological...
BACKGROUND
Major depressive disorder (MDD) has a significant impact on global burden of disease. Complications in clinical management can occur when response to pharmacological modalities is considered inadequate and symptoms persist (treatment-resistant depression (TRD)). We aim to investigate inflammation, proxied by C-reactive protein (CRP) levels, and body mass index (BMI) as putative causal risk factors for depression and subsequent treatment resistance, leveraging genetic information to avoid confounding via Mendelian randomisation (MR).
METHODS
We used the European UK Biobank subcohort ([Formula: see text]), the mental health questionnaire (MHQ) and clinical records. For treatment resistance, a previously curated phenotype based on general practitioner (GP) records and prescription data was employed. We applied univariable and multivariable MR models to genetically predict the exposures and assess their causal contribution to a range of depression outcomes. We used a range of univariable, multivariable and mediation MR models techniques to address our research question with maximum rigour. In addition, we developed a novel statistical procedure to apply pleiotropy-robust multivariable MR to one sample data and employed a Bayesian bootstrap procedure to accurately quantify estimate uncertainty in mediation analysis which outperforms standard approaches in sparse binary outcomes. Given the flexibility of the one-sample design, we evaluated age and sex as moderators of the effects.
RESULTS
In univariable MR models, genetically predicted BMI was positively associated with depression outcomes, including MDD ([Formula: see text] ([Formula: see text] CI): 0.133(0.072, 0.205)) and TRD (0.347(0.002, 0.682)), with a larger magnitude in females and with age acting as a moderator of the effect of BMI on severity of depression (0.22(0.050, 0.389)). Multivariable MR analyses suggested an independent causal effect of BMI on TRD not through CRP (0.395(0.004, 0.732)). Our mediation analyses suggested that the effect of CRP on severity of depression was partly mediated by BMI. Individuals with TRD ([Formula: see text]) observationally had higher CRP and BMI compared with individuals with MDD alone and healthy controls.
DISCUSSION
Our work supports the assertion that BMI exerts a causal effect on a range of clinical and questionnaire-based depression phenotypes, with the effect being stronger in females and in younger individuals. We show that this effect is independent of inflammation proxied by CRP levels as the effects of CRP do not persist when jointly estimated with BMI. This is consistent with previous evidence suggesting that overweight contributed to depression even in the absence of any metabolic consequences. It appears that BMI exerts an effect on TRD that persists when we account for BMI influencing MDD.
Topics: Female; Humans; Body Mass Index; Depressive Disorder, Major; Bayes Theorem; Depression; Inflammation
PubMed: 37710313
DOI: 10.1186/s12916-023-03001-7 -
Neuron Jul 2023Although the etiology of major depressive disorder remains poorly understood, reduced gamma oscillations is an emerging biomarker. Olfactory bulbectomy, an established...
Although the etiology of major depressive disorder remains poorly understood, reduced gamma oscillations is an emerging biomarker. Olfactory bulbectomy, an established model of depression that reduces limbic gamma oscillations, suffers from non-specific effects of structural damage. Here, we show that transient functional suppression of olfactory bulb neurons or their piriform cortex efferents decreased gamma oscillation power in limbic areas and induced depression-like behaviors in rodents. Enhancing transmission of gamma oscillations from olfactory bulb to limbic structures by closed-loop electrical neuromodulation alleviated these behaviors. By contrast, silencing gamma transmission by anti-phase closed-loop stimulation strengthened depression-like behaviors in naive animals. These induced behaviors were neutralized by ketamine treatment that restored limbic gamma power. Taken together, our results reveal a causal link between limbic gamma oscillations and depression-like behaviors in rodents. Interfering with these endogenous rhythms can affect behaviors in rodent models of depression, suggesting that restoring gamma oscillations may alleviate depressive symptoms.
Topics: Animals; Olfactory Bulb; Rodentia; Depression; Depressive Disorder, Major; Neurons
PubMed: 37164008
DOI: 10.1016/j.neuron.2023.04.013 -
JAMA Psychiatry Jul 2023Depression is associated with an increased risk of physical illness, but the most common causes of hospitalization among people with depression are unclear.
IMPORTANCE
Depression is associated with an increased risk of physical illness, but the most common causes of hospitalization among people with depression are unclear.
OBJECTIVE
To examine the association of depression with an array of physical conditions requiring hospital treatment.
DESIGN, SETTING, AND PARTICIPANTS
In this outcomewide prospective multicohort study, primary analysis was based on data from the UK Biobank, a population-based study in the United Kingdom. Analyses were repeated in an independent data set of 2 cohorts in Finland, a population-based study and an occupational cohort. Data analysis was conducted between April and September 2022.
EXPOSURES
Self-reported depression, recurrent severe major depression, recurrent moderate major depression, and a single major depressive episode.
MAIN OUTCOMES AND MEASURES
A total of 77 common health conditions ascertained from linkage data to national hospital and mortality registries.
RESULTS
The analytical sample of UK Biobank participants consisted of 130 652 individuals (71 565 women [54.8%]; 59 087 men [45.2%]; mean [SD] age at baseline, 63.3 [7.8] years). The pooled data from the Finnish replication cohorts included 109 781 participants (82 921 women [78.6%]; 26 860 men [21.4%]; mean [SD] age, 42 [10.8] years). In the main analysis, severe/moderately severe depression was associated with the incidence of 29 nonoverlapping conditions requiring hospital treatment during a 5-year follow-up. Twenty-five of these associations remained after adjustment for confounders and multiple testing (adjusted hazard ratio [HR] range, 1.52-23.03) and were confirmed in the analysis of the Finnish cohorts. These included sleep disorders (HR, 5.97; 95% CI, 3.27-10.89), diabetes (HR, 5.15; 95% CI, 2.52-10.50), ischemic heart disease (HR, 1.76; 95% CI, 1.36-2.29), chronic obstructive bronchitis (HR, 4.11; 95% CI, 2.56-6.60), bacterial infections (HR, 2.52; 95% CI, 1.99-3.19), back pain (HR, 3.99; 95% CI, 2.96-5.38), and osteoarthritis (HR, 1.80; 95% CI, 1.46-2.20). The highest cumulative incidence was observed for endocrine and related internal organ diseases (245 per 1000 persons with depression; risk difference relative to unaffected individuals: 9.8%), musculoskeletal diseases (91 per 1000 persons; risk difference, 3.7%), and diseases of the circulatory system and blood (86 per 1000 persons; risk difference, 3.9%). The cumulative incidence was lower for hospital-treated mental, behavioral, and neurological disorders (20 in 1000 persons; risk difference, 1.7%). Depression was also associated with disease progression in people with prevalent heart disease or diabetes, and for 12 conditions, there was evidence of a bidirectional relationship.
CONCLUSIONS AND RELEVANCE
In this study, the most common causes of hospitalization in people with depression were endocrine, musculoskeletal, and vascular diseases, not psychiatric disorders. These findings suggest that depression should be considered as a target for the prevention of physical and mental disease.
Topics: Male; Humans; Female; Adult; Child; Prospective Studies; Depression; Depressive Disorder, Major; Diabetes Mellitus; Hospitalization; Risk Factors
PubMed: 37133850
DOI: 10.1001/jamapsychiatry.2023.0777 -
Psychiatry Research Aug 2023Evidence supports the antidepressant effects of resistance exercise training (RET); however, findings among young adults at-risk for elevated depressive symptoms are... (Randomized Controlled Trial)
Randomized Controlled Trial
Evidence supports the antidepressant effects of resistance exercise training (RET); however, findings among young adults at-risk for elevated depressive symptoms are limited. This randomized controlled trial examined the effects of eight weeks of ecologically-valid, guidelines-based RET, compared to a wait-list control, on depressive symptoms among 55 young adults (26±5y; 36 female) with and without subclinical, or analogue, Generalized Anxiety Disorder (AGAD; Psychiatric Diagnostic Screening Questionnaire GAD subscale ≥6 and Penn State Worry Questionnaire ≥45) and Major Depressive Disorder (AMDD). Following a three-week familiarization period, participants completed one-on-one, twice-weekly RET sessions. The 16-item, self-reported Quick Inventory of Depressive Symptomatology (QIDS) assessed depressive symptoms. RM-ANCOVAs examined between-group differences, and significant interactions were decomposed with simple effects analysis. Hedges' d effect sizes (95%CI) quantified the magnitude of differences in change between groups across time. Stratified analyses were conducted among subsamples with AMDD and AGAD. There were no baseline depressive symptom differences between groups. Attendance was 83%, and compliance was 80%. RET induced statistically significant, clinically-meaningful, large-magnitude reductions in depressive symptoms from baseline to week eight in the total (d = 1.01; [95%CI: 0.44-1.57]), AMDD (d = 1.71; [95%CI: 0.96-2.46]), and AGAD (d = 1.39; [95%CI: 0.55-2.24]) samples. These findings support guidelines-based RET as a promising treatment for mild depression.
Topics: Humans; Female; Young Adult; Depression; Resistance Training; Depressive Disorder, Major; Exercise; Anxiety Disorders
PubMed: 37429171
DOI: 10.1016/j.psychres.2023.115322 -
Journal of Neuroinflammation Nov 2023As one of most common and severe mental disorders, major depressive disorder (MDD) significantly increases the risks of premature death and other medical conditions for... (Review)
Review
As one of most common and severe mental disorders, major depressive disorder (MDD) significantly increases the risks of premature death and other medical conditions for patients. Neuroinflammation is the abnormal immune response in the brain, and its correlation with MDD is receiving increasing attention. Neuroinflammation has been reported to be involved in MDD through distinct neurobiological mechanisms, among which the dysregulation of neurogenesis in the dentate gyrus (DG) of the hippocampus (HPC) is receiving increasing attention. The DG of the hippocampus is one of two niches for neurogenesis in the adult mammalian brain, and neurotrophic factors are fundamental regulators of this neurogenesis process. The reported cell types involved in mediating neuroinflammation include microglia, astrocytes, oligodendrocytes, meningeal leukocytes, and peripheral immune cells which selectively penetrate the blood-brain barrier and infiltrate into inflammatory regions. This review summarizes the functions of the hippocampus affected by neuroinflammation during MDD progression and the corresponding influences on the memory of MDD patients and model animals.
Topics: Adult; Animals; Humans; Depressive Disorder, Major; Depression; Neuroinflammatory Diseases; Hippocampus; Neurogenesis; Mammals
PubMed: 38012702
DOI: 10.1186/s12974-023-02964-x -
JAMA Psychiatry Aug 2023The microbiota-gut-brain axis is a promising target for novel treatments for mood disorders, such as probiotics. However, few clinical trials have been conducted, and... (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
The microbiota-gut-brain axis is a promising target for novel treatments for mood disorders, such as probiotics. However, few clinical trials have been conducted, and further safety and efficacy data are needed to support this treatment approach.
OBJECTIVE
To provide acceptability and tolerability data and estimates of intervention effect size for probiotics as adjunctive treatment for patients with major depressive disorder (MDD).
DESIGN, SETTING, AND PARTICIPANTS
In this single-center, double-blind, placebo-controlled pilot randomized clinical trial, adults aged 18 to 55 years with MDD taking antidepressant medication but having an incomplete response were studied. A random sample was recruited from primary and secondary care services and general advertising in London, United Kingdom. Data were collected between September 2019 and May 2022 and analyzed between July and September 2022.
INTERVENTION
Multistrain probiotic (8 billion colony-forming units per day) or placebo daily for 8 weeks added to ongoing antidepressant medication.
MAIN OUTCOMES AND MEASURES
The pilot outcomes of the trial were retention, acceptability, tolerability, and estimates of putative treatment effect on clinical symptoms (depression: Hamilton Depression Rating Scale [HAMD-17] and Inventory of Depressive Symptomatology [IDS] scores; anxiety: Hamilton Anxiety Rating Scale [HAMA] and General Anxiety Disorder [GAD-7] scores) to be used as indicators for a definitive trial.
RESULTS
Of 50 included participants, 49 received the intervention and were included in intent-to-treat analyses; of these, 39 (80%) were female, and the mean (SD) age was 31.7 (9.8) years. A total of 24 were randomized to probiotic and 25 to placebo. Attrition was 8% (1 in the probiotic group and 3 in the placebo group), adherence was 97.2%, and there were no serious adverse reactions. For the probiotic group, mean (SD) HAMD-17 scores at weeks 4 and 8 were 11.00 (5.13) and 8.83 (4.28), respectively; IDS, 30.17 (11.98) and 25.04 (11.68); HAMA, 11.71 (5.86) and 8.17 (4.68); and GAD-7, 7.78 (4.12) and 7.63 (4.77). For the placebo group, mean (SD) HAMD-17 scores at weeks 4 and 8 were 14.04 (3.70) and 11.09 (3.22), respectively; IDS, 33.82 (9.26) and 29.64 (9.31); HAMA, 14.70 (5.47) and 10.95 (4.48); and GAD-7, 10.91 (5.32) and 9.48 (5.18). Standardized effect sizes (SES) from linear mixed models demonstrated that the probiotic group attained greater improvements in depressive symptoms according to HAMD-17 scores (week 4: SES, 0.70; 95% CI, 0.01-0.98) and IDS Self Report scores (week 8: SES, 0.64; 95% CI, 0.03-0.87) as well as greater improvements in anxiety symptoms according to HAMA scores (week 4: SES, 0.67; 95% CI, 0-0.95; week 8: SES, 0.79; 95% CI, 0.06-1.05), but not GAD-7 scores (week 4: SES, 0.57; 95% CI, -0.01 to 0.82; week 8: SES, 0.32; 95% CI, -0.19 to 0.65), compared with the placebo group.
CONCLUSIONS AND RELEVANCE
The acceptability, tolerability, and estimated effect sizes on key clinical outcomes are promising and encourage further investigation of probiotics as add-on treatment for people with MDD in a definitive efficacy trial.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT03893162.
Topics: Adult; Humans; Female; Male; Depressive Disorder, Major; Depression; Antidepressive Agents; Anxiety Disorders; Double-Blind Method; Treatment Outcome
PubMed: 37314797
DOI: 10.1001/jamapsychiatry.2023.1817