This systematic review and meta-analysis aimed to quantify the magnitude of placebo and nocebo effects in pharmacological trials for OCRDs and identify clinical and methodological moderators influencing these effects.

A comprehensive literature search was conducted across multiple databases and clinical trial registries up to May 2025. Randomized, placebo-controlled trials involving pharmacological interventions for OCRDs were included. The primary outcomes were placebo effect size and placebo response rate; secondary outcomes included nocebo response rate and side effect profile. Data were extracted independently and meta-analysed using random-effects models. Meta-regression was performed to assess moderators of placebo response.

Fifteen eligible trials (N = 640; placebo N = 341) were included. The pooled placebo effect size was moderate (SMC = -0.63; 95% CI -0.77 to -0.48), with low heterogeneity (I2 = 4.73%). The placebo response rate was 21%, and the nocebo response rate was 18%. Despite testing a broad range of potential moderators, including clinical characteristics, methodological design, and medication class, no significant predictors of placebo effect size were identified. Side effects were reported in nearly one-third of placebo recipients, underscoring the relevance of nocebo effects.

Placebo and nocebo responses are noteworthy in trials for OCRDs and may influence perceived treatment efficacy. Variability in placebo responses is not well explained by currently measurable moderators. Further research is needed to explore neurobiological, psychological, and methodological contributors to expectancy effects in OCRD pharmacotherapy trials.

The comorbidity of psychiatric and metabolic conditions is prevalent and poses a heavy burden on public health. Several biopsychosocial factors are known to influence both metabolic and psychiatric health, including inflammation, eating behavior, physical activity, and early life stress. Few studies, however, have examined the constellation of interrelationships among multiple risk domain simultaneously.

Using a sample of 200 medically healthy adults enrolled in a parent study, we used Gaussian Graphical Modeling, a type of network analysis, to characterize interdependent cross-sectional associations between early life stress (childhood trauma), health behaviors (diet quality and physical activity), blood-based biomarkers of metabolic functioning (insulin resistance, HDL cholesterol, triglycerides) and inflammation (C-reactive protein [CRP]), and three domains of mental health symptoms (depressive, anxious, and post-traumatic stress symptoms). We hypothesized that the network structure would highlight a pattern whereby higher CRP, poorer diet quality, lower physical activity, and higher childhood trauma, would associate with increased risk for both metabolic and psychiatric impairments.

Findings revealed a positive conditional association between CRP and childhood trauma, which may function as an intermediary process to increase risk for both metabolic impairments and psychiatric symptoms in adulthood. Further, higher physical activity was associated with lower insulin resistance and fewer depressive symptoms, and better diet quality was associated with lower CRP levels.

Results highlight potential avenues for interventions aimed at reducing inflammation, improving health behavior, and addressing the effects of childhood trauma to improve physical and mental health comorbidities.

A previous study by our research group identified psychomotor and neurofunctional impairments following SARS-CoV-2 infection. This study continues that investigation, aiming to evaluate whether these impairments persisted over time, as part of the broader characterization of long COVID. Moreover, it was explored potential correlations with variables such as age, blood type, symptoms, and medical care.

From an initial pool of 214 subjects, 30 post-COVID-19 participants and 30 healthy controls were selected after strict exclusion criteria. The assessments protocol included eight psychomotor tests–Fine Motor Development (Diadochokinesia, Puppets, Fan, and Paper) and Balance (Immobility, Static Balance on One Foot, Feet in Line, and Persistence)–as well as three cognitive screening tasks from the Mini-Mental State Examination: Episodic Memory After Distracters, Verbal Fluency, and Clock tests. Evaluations were performed at three time points: baseline (post-COVID-19), 12 weeks, and 24 weeks. Participants were stratified by age (18–30, 31–45, and 46–64 years), symptoms profile, medical care, and blood type.

COVID-19 induced psychomotor and neurofunctional sequelae lasting at least 24 weeks post-infection. These impairments were more pronounced and persistent in the 31-45-years age group, while memory-related impairments were more evident in the 18-30 age group. Body pain, coryza, and sore throat were key symptoms linked to long-term sequelae. Rh-negative blood type was suggested as a potential risk factor.

The findings support that long COVID included sustained psychomotor and neurofunctional sequelae, premature senescence, and associations with specific clinical and biological variables.

Major depressive disorder (MDD) is a neuro-immune, oxidative, and nitrosative stress (NIMETOX) disorder, in which peripheral immune-redox pathways intersect with metabolic networks leading to neurotoxicity within the limbic-prefrontal affective circuits. Comprehensive metabolomics analysis in well-phenotyped patients is vital to elucidate their metabolic profile.

To identify metabolic abnormalities that differentiate inpatients with severe MDD from healthy controls through high-resolution, untargeted metabolomics.

Serum samples from 125 MDD inpatients and 40 healthy controls were analyzed utilizing liquid chromatography and mass spectrometry. A meticulously regulated multistage machine learning pipeline with leakage-prevention protocols was employed to analyze differences between MDD and controls and to predict phenome scores.

Feature selection showed that 16 metabolites and 6 functional modules reliably distinguished MDD. The functional profile of the metabolites indicates a convergence of lipotoxicity, phospholipid remodeling, disruptions in fatty acid metabolism, mitochondrial redox imbalance, ether-lipid metabolism, and antioxidant depletion. This MDD metabotype was not affected by metabolic syndrome. A substantial portion of the variance in overall depression severity (72.5%), physiosomatic symptoms (55.8%) and suicidal ideation (23.6%) was accounted for by increased lipotoxicity, phospholipid remodeling, and fatty acid storage/signaling. The recurrence of illness (27.7%) was associated with a self-reinforcing lipid-redox-inflammatory module that maintains cellular stress.

The MDD metabotype represents a cohesive metabolic network that is associated with the NIMETOX pathogenesis of MDD. Metabolomics provides a comprehensive foundation for subtyping and precision psychiatry. Lipoxygenase-15, lipotoxicity, phospholipase A2, and lipid-redox intersections might be important drug targets to treat MDD.

Low heart rate variability (HRV) levels may be a susceptibility factor for major depressive disorder (MDD). Sleep-state HRV may be more likely to reveal the pathological features of MDD compared with resting state HRV (RS-HRV). This study aimed to elucidate HRV alterations in the sleep states of patients with MDD.

Physiological signal data from the resting state before sleep, first non-rapid eye movement (NREM) and rapid eye movement (REM) stages, and last NREM and REM stages were acquired using polysomnography.

The RS-HRV indices (the standard deviation [SD] of all normal-to-normal [NN] intervals [SDNN], the square root of the mean of the sum of the squares of the differences between adjacent NN intervals [RMSSD], the percentage difference between adjacent NN intervals >50 ms [pNN50], high-frequency [HF], low-frequency [LF], very low frequency [VLF], SD1, and sample entropy [SampEn]) were lower in patients with MDD than in healthy controls (HCs). Patients with MDD had lower SDNN, RMSSD, pNN50, HF, LF, VLF, SD1, SD2, and SampEn and higher SD2/SD1, α1, and α2 than HCs in the NREM stage. They also had lower SDNN, RMSSD, pNN50, HF, LF, VLF, SD1, SD2, and SampEn and higher LF/HF than HCs in the REM stage. Fewer indices changed significantly during different sleep stages in patients with MDD than in HCs.

Patients with MDD had a generalized reduction in HRV in both RS and sleep state and decreased dynamic changes during sleep. Altered autonomic nervous system activity has been implicated in MDD pathology.

There are differences in IgA responses to tryptophan catabolites (TRYCATs) in major neurocognitive psychosis (MNP) versus simple neurocognitive psychosis (SNP) and normal controls. MNP and SNP are distinct schizophrenia classes which are differentiated by neurocognitive deficits, phenome features, and biomarker pathways. Nevertheless, there is no data on serum concentrations of those TRYCATs in MNP and SNP. The aim of the present study is to examine serum concentrations of tryptophan and TRYCATs in MNP versus SNP and controls.

This case-control study examines serum levels of tryptophan and TRYCATs in 52 MNP patients, 68 SNP patients and 60 controls in association with overall severity of schizophrenia (OSOS).

MNP patients show lower tryptophan, kynurenic acid (KA), 3-OH-anthranilic acid (3HAA), and higher anthranilic acid (AA) and quinolinic acid (QA) than SNP patients and controls. There were no differences between SNP and controls in these TRYCATs. Kynurenine (KYN) was lower in MNP+SNP than in controls. We found that 36.5% of the variance in OSOS was explained by the combined effects of lowered tryptophan, KA, and 3-HK, and increased QA and AA. The most important biomarkers of MNP and OSOS were the QA/KA ratio followed by the QA/3HAA ratio.

The alterations in serum TRYCAT levels further emphasize that MNP and SNP represent two biologically distinct subtypes of schizophrenia. The reductions in TRYCATs diminish the antioxidant and immunoregulatory functions of the TRYCAT pathway. Elevated QA levels may exacerbate the disruption of the blood-brain barrier and the immune-related and oxidative neurotoxicity in MNP.

Metabolic syndrome (MetS) is highly prevalent among adults and is frequently accompanied by depressive symptoms. While high-sensitivity C-reactive protein (hsCRP) has been proposed as a potential indicator of depression, existing evidence remains inconclusive.

This study aimed to determine whether increased serum hsCRP or other immune-metabolic biomarkers are associated with depressive symptoms in drug-naïve individuals with obesity and MetS.

A total of 88 drug-naïve patients with obesity and MetS but without coronary-artery disease were enrolled and serum levels of neuro-immune and metabolic biomarkers were assessed.

In MetS, the severity of depression, as assessed using the von Zerssen Depression Rating (VZDR) scale was significantly associated with interleukin (IL)-6, leukocyte numbers, triglyceride x glucose (Tyg) index, low-density lipoprotein cholesterol, Apolipoprotein B (all positively) and mean platelet volume (MPV), visfatin and adiponectin (all negatively). There were no significant associations between hsCRP and severity of depression. In MetS patients, hsCRP is strongly associated with increased leukocyte numbers, alkaline phosphatase, γ-glutamyl transferase, uric acid, platelet numbers and MPV, thereby shaping a distinct subtype of MetS, which is not related to depression.

Our findings indicate that depressive symptoms in MetS patients are associated with immune–metabolic biomarkers indicating immune activation, atherogenicity and insulin resistance, but not with hsCRP. The reason is that hsCRP in MetS is a biomarker of a specific MetS subtype that is characterized by megakaryopoiesis, hepatocyte activation, and uric acid production, which were not associated with depression.