BACKGROUND: The optimal antidepressant dosages remain controversial. This study aimed to analyze the efficacy of antidepressants and characterize their dose-response relationships in the treatments of major depressive disorders (MDD). METHODS: We searched multiple databases, including the Embase, Cochrane Central Register of Controlled Trials, PubMed, and Web of Science, for the studies that were conducted between January 8, 2016, and April 30, 2023. The studies are double-blinded, randomized controlled trials (RCTs) involving the adults (≥18 years) with MDD. The primary outcomes were efficacy of antidepressant and the dose-response relationships. A frequentist network meta-analysis was conducted, treating participants with various dosages of the same antidepressant as a single therapy. We also implemented the model-based meta-analysis (MBMA) using a Bayesian method to explore the dose-response relationships. RESULTS: The network meta-analysis comprised 135,180 participants from 602 studies. All the antidepressants were more effective than the placebo; toludesvenlafaxine had the highest odds ratio (OR) of 4.52 (95% confidence interval [CI]: 2.65-7.72), and reboxetine had the lowest OR of 1.34 (95%CI: 1.14-1.57). Moreover, amitriptyline, clomipramine, and reboxetine showed a linear increase in effect size from low to high doses. The effect size of toludesvenlafaxine increased significantly up to 80 mg/day and subsequently maintained the maximal dose up to 160 mg/day while the predictive curves of nefazodone were fairly flat in different dosages. CONCLUSIONS: Although most antidepressants were more efficacious than placebo in treating MDD, no consistent dose-response relationship between any antidepressants was observed. For most antidepressants, the maximum efficacy was achieved at lower or middle prescribed doses, rather than at the upper limit. REGISTRATION No. CRD42023427480; https://www.crd.york.ac.uk/prospero/display_record.php?
Humans ; Antidepressive Agents/therapeutic use* ; Depressive Disorder, Major/drug therapy* ; Dose-Response Relationship, Drug ; Randomized Controlled Trials as Topic

Major depressive disorder (MDD) affects people all over the world, and yet, its etiology is complex and remains incompletely understood. In this review, we aim to assess recent advances in understanding depression and its regulation, as well as its interaction with circadian rhythms. Circadian rhythms are internalized representations of the periodic daily light and dark cycles. Accumulating evidence has shown that MDD and the related mental disorders are associated with disrupted circadian rhythms. In particular, depression has often been linked to abnormalities in circadian rhythms because dysregulation of the circadian system increases susceptibility to MDD. The fact that several rhythms are disrupted in depressed patients suggests that these disruptions are not restricted to any one rhythm but rather involve the molecular circadian clock core machinery. The sleep-wake cycle is one rhythm that is often disrupted in depression, which often leads to disturbances in other rhythms. The circadian disruptions manifested in depressed patients and the effectiveness and fast action of chronobiologically based treatments highlight the circadian system as a key therapeutic target in the treatment of depression. This review assesses the evidence on rising depression rates and examines their contributing factors, including circadian misalignment. We discuss key hypotheses underlying depression pathogenesis, potential etiology, and relevant animal models, and underscore potential mechanisms driving depression's growing burden and how understanding these factors is critical for improving prevention and treatment strategies.
Humans ; Circadian Rhythm/physiology* ; Depressive Disorder, Major/therapy* ; Animals ; Sleep/physiology* ; Depression/therapy*

BACKGROUND: Depression among older adults is an important public health issue, and air and noise pollution have been found to contribute to exacerbation of depressive symptoms. This study examined the association of exposure to air and noise pollutants with clinically-newly-diagnosed depressive disorder. The mediating role of individual pro-inflammatory markers was explored. METHODS: We linked National Health Insurance claim data with 2998 healthy community-dwellers aged 55 and above who participated in the Healthy Aging Longitudinal Study between 2009 and 2013. Newly diagnosed depressive disorder was identified using diagnostic codes from the medical claim data. Pollutants were estimated using nationwide land use regression, including PM_2.5 and PM₁₀, carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, and road traffic noise. Cox proportional hazard models were employed to examine the association between pollutants and newly developed depressive disorders. The mediating effect of serum pro-inflammatory biomarkers on the relationship was examined. RESULTS: Among the 2998 participants, 209 had newly diagnosed depressive disorders. In adjusted Cox proportional hazard models, one interquartile range increase in PM_2.5 (8.53 µg/m³) was associated with a 17.5% increased hazard of developing depressive disorders. Other air pollutants and road traffic noise were not linearly associated with depressive disorder incidence. Levels of serum tumor necrosis factor receptor 1 mediated the relationship between PM_2.5 and survival time to newly onset depressive disorder. CONCLUSION PM_2.5 is related to an increased risk of newly developed depressive disorder among middle-aged and older adults, and the association is partially mediated by the pro-inflammatory marker TNF-R1.
Humans ; Particulate Matter/analysis* ; Male ; Female ; Middle Aged ; Longitudinal Studies ; Aged ; Incidence ; Air Pollutants/analysis* ; Environmental Exposure/adverse effects* ; Taiwan/epidemiology* ; Receptors, Tumor Necrosis Factor, Type I/blood* ; Proportional Hazards Models ; Biomarkers/blood* ; Depression/epidemiology* ; Aged, 80 and over ; Depressive Disorder/chemically induced* ; Risk Factors ; Air Pollution/adverse effects*

Premenstrual dysphoric disorder (PMDD) is considered a severe form of premenstrual syndrome (PMS). As a key brain region involved in emotional regulation and stress responses, the amygdala has been implicated in the pathogenesis of PMS/PMDD. The amygdala is composed of multiple subregions, each playing distinct roles in emotion, memory, and stress responses, and forms complex brain areas. Summarizing the interconnections among amygdala, subregions and their connectivity with external areas, and exploringt the neuroimaging characteristics of the amygdala, as well as changes in its neural circuits and brain networks in these patients, will help provide a theoretical foundation for targeted modulation of amygdala function in the treatment of PMS/PMDD.
Humans ; Amygdala/diagnostic imaging* ; Female ; Premenstrual Dysphoric Disorder/pathology* ; Premenstrual Syndrome/pathology* ; Emotions/physiology* ; Magnetic Resonance Imaging

The relationship between gut microbiota and depressive disorder has become a research focus in recent years. Within the microbiota-gut-brain axis, the gut microbiota influences the onset and progression of depressive disorder primarily through the tryptophan metabolic pathway. Tryptophan, an essential amino acid in humans, is subject to dual regulation by intestinal microorganisms, which modulate its metabolic balance via inflammatory stimulation and microbial metabolite production. In depression, excessive activation of the kynurenine branch of tryptophan metabolism leads to the accumulation of proinflammatory and neurotoxic metabolites, thereby exacerbating neuroinflammation in the brain. Intervention studies indicate that the antidepressant-like effects of probiotics and traditional Chinese medicine are associated with remodeling of the gut microbiota, restoration of tryptophan metabolic balance, and alleviation of neuroinflammation. Furthermore, targeted inhibition of kynurenine 3-monooxygenase can mitigate neuroinflammation by regulating microglial activity, thus improving depressive-like behaviors. In summary, the metabolite-inflammation axis represents a central node in the interaction regulation between tryptophan metabolism and the microbiota-gut-brain axis. This provides a theoretical foundation for developing novel therapeutic strategies targeting depression through modulation of gut microbiota-mediated tryptophan metabolism.
Tryptophan/metabolism* ; Gastrointestinal Microbiome/physiology* ; Humans ; Depressive Disorder/microbiology* ; Probiotics/therapeutic use* ; Brain/metabolism* ; Kynurenine/metabolism* ; Metabolic Networks and Pathways ; Animals ; Medicine, Chinese Traditional

OBJECTIVES: To explore the role of C1q, the promoter of the classical pathway of the complement system, in regulating postpartum depressive-like behaviors in mice and the therapeutic mechanism of C1q-neutralizing antibodies. METHODS: Female C57BL/6 mouse models of postpartum depression established by hormone-simulated pregnancy (HSP) were evaluated for depression-like behaviors, and peripheral blood levels and hippocampal expressions of C1q were detected using ELISA and Western blotting. Immunofluorescence staining was used for detecting co-labeling of C1q and microglia, and the differentially expressed mRNAs in the hippocampus of HSP mice were analyzed using RNA sequencing. The Edinburgh Postnatal Depression Scale was used to screen patients with postpartum depression, from whom peripheral blood mononuclear cells were extracted for detecting C1q expression levels with Western blotting. The HSP mice were subjected to stereotactic injection of C1q-neutralizing antibody or a control IgG in the hippocampus, and the changes in depressive-like behaviors and hippocampal expression of C3 were examined. RESULTS: The HSP mice exhibited obvious depressive behaviors, demonstrated by significantly decreased preference for sugar water and increased forced swimming and tail suspension time. The mouse models showed significantly increased peripheral blood C1q level and hippocampal expression level of C1q, accompanied by an increase in Iba1 and C1q co-labeling in the hippocampus. The expression level of C1q in peripheral monocytes was also significantly increased in patients with postpartum depression. In HSP mice, stereotactic injection of C1q-neutralizing antibody, but not the control IgG, obviously alleviated depressive-like behaviors, shown by significantly increased preference for sugar water and decreased forced swimming and tail suspension time, resulting also in decreased expression of C3 in the hippocampus and lowered serum levels of IL-6 and TNF-α. CONCLUSIONS C1q-neutralizing antibodies improve postpartum depressive-like behaviors in mice possibly by regulating the C1q/C3 signaling pathway.
Animals ; Female ; Depression, Postpartum ; Complement C1q/metabolism* ; Antibodies, Neutralizing/pharmacology* ; Mice, Inbred C57BL ; Mice ; Hippocampus/metabolism* ; Pregnancy ; Disease Models, Animal

This study explored how the human cortical folding pattern composed of convex gyri and concave sulci affected single-subject morphological brain networks, which are becoming an important method for studying the human brain connectome. We found that gyri-gyri networks exhibited higher morphological similarity, lower small-world parameters, and lower long-term test-retest reliability than sulci-sulci networks for cortical thickness- and gyrification index-based networks, while opposite patterns were observed for fractal dimension-based networks. Further behavioral association analysis revealed that gyri-gyri networks and connections between gyral and sulcal regions significantly explained inter-individual variance in Cognition and Motor domains for fractal dimension- and sulcal depth-based networks. Finally, the clinical application showed that only sulci-sulci networks exhibited morphological similarity reductions in major depressive disorder for cortical thickness-, fractal dimension-, and gyrification index-based networks. Taken together, these findings provide novel insights into the constraint of the cortical folding pattern to the network organization of the human brain.
Humans ; Cerebral Cortex/anatomy & histology* ; Male ; Female ; Magnetic Resonance Imaging ; Adult ; Connectome/methods* ; Young Adult ; Nerve Net/anatomy & histology* ; Neural Pathways ; Depressive Disorder, Major/diagnostic imaging*

Depressive disorder is a chronic, recurring, and potentially life-endangering neuropsychiatric disease. According to a report by the World Health Organization, the global population suffering from depression is experiencing a significant annual increase. Despite its prevalence and considerable impact on people, little is known about its pathogenesis. One major reason is the scarcity of reliable animal models due to the absence of consensus on the pathology and etiology of depression. Furthermore, the neural circuit mechanism of depression induced by various factors is particularly complex. Considering the variability in depressive behavior patterns and neurobiological mechanisms among different animal models of depression, a comparison between the neural circuits of depression induced by various factors is essential for its treatment. In this review, we mainly summarize the most widely used behavioral animal models and neural circuits under different triggers of depression, aiming to provide a theoretical basis for depression prevention.
Animals ; Disease Models, Animal ; Depressive Disorder/psychology* ; Humans ; Behavior, Animal/physiology* ; Nerve Net/physiopathology* ; Brain/physiopathology* ; Neural Pathways/physiopathology*

Repetitive transcranial magnetic stimulation (rTMS) is a rapid and effective therapy for major depressive disorder; however, there is significant variability in therapeutic outcomes both within and across individuals, with approximately 50% of patients showing no response to rTMS treatment. Many studies have personalized the stimulation parameters of rTMS (e.g., location and intensity of stimulation) according to the anatomical and functional structure of the brain. In addition to these parameters, the internal states of the individual, such as circadian rhythm, behavior/cognition, neural oscillation, and neuroplasticity, also contribute to the variation in rTMS effects. In this review, we summarize the current literature on the interaction between rTMS and internal states. We propose two possible methods, multimodal treatment, and adaptive closed-loop treatment, to integrate patients' internal states to achieve better rTMS treatment for depression.
Humans ; Transcranial Magnetic Stimulation/methods* ; Depressive Disorder, Major/physiopathology* ; Neuronal Plasticity/physiology* ; Brain/physiopathology*

BACKGROUND: Acupuncture therapy provides a complementary and alternative approach to treating major depressive disorder (MDD), but its efficacy and safety have still not been comprehensively assessed. Recently published systematic reviews remain confusing and inconclusive. OBJECTIVE: This systematic review evaluated the efficacy and safety of acupuncture therapy alone or combined with antidepressants for adult patients with mild and moderate MDD. SEARCH STRATEGY: Chinese Biomedical Literature Database, China National Knowledge Infrastructure Database, Wanfang Database, Chinese Science and Technology Journal Database, PubMed, Embase, and Cochrane Library were searched from their inceptions to March 2025. INCLUSION CRITERIA: Randomized controlled trials that compared acupuncture therapy with antidepressants, or acupuncture therapy plus antidepressants with acupuncture therapy or antidepressants for adult patients with mild and moderate MDD were included. DATA EXTRACTION AND ANALYSIS: Five reviewers independently extracted data from original literature using a standardized form, and the data were verified by two reviewers to ensure accuracy. Statistical meta-analyses, publication bias analyses, and subgroup analyses were performed by using Review Manager 5.3 software. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess the certainty of the evidence. RESULTS: A total of 60 eligible studies including 4675 participants were included. Low-certainty evidence showed that compared with antidepressants, acupuncture therapy (standardized mean difference [SMD] = -0.57; 95% confidence interval [CI] = [-0.87, -0.27]; I² = 86%; P = 0.006) or acupuncture therapy plus antidepressants (SMD = -1.00; 95% CI = [-1.18, -0.81]; I² = 77%; P < 0.00001) may reduce the severity of depression at the end of treatment. Low-certainty evidence indicated that compared with acupuncture therapy alone, acupuncture therapy plus antidepressants slightly reduced the severity of depression at the end of treatment (SMD = -0.38; 95% CI = [-0.61, -0.14]; I² = 18%; P = 0.002). Similar results were also found for acupuncture's relief of insomnia. The reported adverse effects of acupuncture therapy were mild and transient. For most of the subgroup analyses, acupuncture type, scale type, and the course of treatment did not show a significant relative effect. CONCLUSION Acupuncture therapy may provide antidepressant effects and relieve insomnia with mild adverse effects for adult patients with mild and moderate MDD. But the certainty of evidence was very low. More high-quality, well designed, large-scale studies with long-term follow-up are needed in the future. Please cite this article as: Kuang HJ, Yang HS, Feng YX, Tang H, Fan Q, Xu YQ, Cui S, Musil R, Luxenburger H, Zhang YX, Zhao H, Zhang YQ. Efficacy and safety of acupuncture therapies for adult patients with mild and moderate major depressive disorder: A systematic review and meta-analysis. J Integr Med. 2025; 23(5):471-491.
Humans ; Acupuncture Therapy/methods* ; Depressive Disorder, Major/therapy* ; Adult ; Antidepressive Agents/therapeutic use* ; Treatment Outcome ; Randomized Controlled Trials as Topic