Contrary to the negative acute-phase protein (APP) response, there is no consistent correlation between serum pentameric C-reactive protein (pCRP) and major depression (MDD). Monomeric CRP (mCRP), a dissociation product of pCRP under immune-inflammatory conditions, exhibits pro-inflammatory effects; however, it has not been investigated in MDD or its subtypes, major dysmood disorder (MDMD) and simple dysmood disorder (SDMD).

To examine serum mCRP, albumin, transferrin, M1 macrophage and Thelper-17 immune profiles, and adverse childhood experiences (ACEs) in MDD, MDMD and SDMD.

Seventy-nine MDMD patients, 30 SDMD patients, and 40 controls were included. Serum mCRP was measured by ELISA; albumin, transferrin, and pCRP by biochemical assays; and cytokines using Luminex technology.

MDMD patients showed significantly higher mCRP compared with SDMD and controls, while both patient groups exhibited reduced albumin and transferrin. Combining mCRP with albumin and transferrin showed an adequate accuracy for MDD (area under the ROC Curve = 0.793). Adding IL-17A and ACEs improved accuracy (ROC=0.855). Serum mCRP levels are additionally associated with pCRP, M1 macrophage profile, body mass index, and ACEs. Up to 36.6% of the variance in overall severity of depression was explained by mCRP, T-helper-17 profile, ACEs (all positively), albumin and transferrin (both inversely).

Future research in MDD should employ mCRP rather than pCRP as a biomarker of depression/MDMD. Combining mCRP with biomarkers of the negative acute-phase response identified 63.7% of MDD patients with a smoldering acute-phase response, with a specificity of 82.1%. We recommend to assess mCRP rather than pCRP in MDD studies.

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.

Genetic research on nicotine dependence has utilized multiple assessments that are in weak agreement.

We conducted a genome-wide association study (GWAS) of nicotine dependence defined using the Diagnostic and Statistical Manual of Mental Disorders (DSM-NicDep) in 61,861 individuals (47,884 of European ancestry [EUR], 10,231 of African ancestry, and 3,746 of East Asian ancestry) and compared the results to other nicotine-related phenotypes.

We replicated the well-known association at the CHRNA5 locus (lead single-nucleotide polymorphism [SNP]: rs147144681, p = 1.27E−11 in EUR; lead SNP = rs2036527, p = 6.49e−13 in cross-ancestry analysis). DSM-NicDep showed strong positive genetic correlations with cannabis use disorder, opioid use disorder, problematic alcohol use, lung cancer, material deprivation, and several psychiatric disorders, and negative correlations with respiratory function and educational attainment. A polygenic score of DSM-NicDep predicted DSM-5 tobacco use disorder criterion count and all 11 individual diagnostic criteria in the independent National Epidemiologic Survey on Alcohol and Related Conditions-III sample. In genomic structural equation models, DSM-NicDep loaded more strongly on a previously identified factor of general addiction liability than a “problematic tobacco use” factor (a combination of cigarettes per day and nicotine dependence defined by the Fagerström Test for Nicotine Dependence). Finally, DSM-NicDep showed a strong genetic correlation with a GWAS of tobacco use disorder as defined in electronic health records (EHRs).

Our results suggest that combining the wide availability of diagnostic EHR data with nuanced criterion-level analyses of DSM tobacco use disorder may produce new insights into the genetics of this disorder.

Neuropsychiatric disorders in preeclampsia (PE) women are prevalent and worsen PE outcome. Immune-related biomarkers including soluble sCD80 and cytotoxic T-lymphocyte antigen-4 (sCTLA-4) are not well studied in relation to depression, anxiety, and chronic fatigue due to PE.

The aim is to study serum immune-inflammatory biomarkers of PE and delineate their associations with the Hamilton Depression (HAMD), Anxiety (HAMA), and Fibro-Fatigue (FF) rating Scale scores. sCD80, sCTLA-4, vitamin D, granulocyte-macrophage colony-stimulating factor, zinc, copper, magnesium, and calcium were measured in 90 PE compared with 60 non-PE pregnant women.

PE women show higher depression, anxiety and FF rating scale scores as compared with control women. sCTLA-4, sCD80, and copper were significantly higher and zinc, magnesium, and calcium significantly lower in PE women than in controls. Multiple regression analysis showed that around 55.8%-58.0% of the variance in the HAMD, HAMA and FF scores was explained by the regression on biomarkers; the top 3 most important biomarkers were sCTLA-4, sCD80, and vitamin D. The sCTLA-4/sCD80 ratio was significantly and inversely associated with the HAMD/HAMA/FF scores. We found that around 70% of the variance in systolic blood pressure could be explained by sCTLA-4, vitamin D, calcium, and copper.

The findings underscore that PE and depression, anxiety, and chronic fatigue symptoms due to PE are accompanied by activation of the immune-inflammatory response system. More specifically, disbalances among soluble checkpoint molecules seem to be involved in the pathophysiology of hypertension and neuropsychiatric symptoms due to PE.

Persistent infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), reactivation of dormant viruses, and immune-oxidative responses are involved in long COVID.

To investigate whether long COVID and depressive, anxiety, and chronic fatigue syndrome (CFS) symptoms are associated with IgA/IgM/IgG to SARS-CoV-2, human herpesvirus type 6 (HHV-6), Epstein-Barr Virus (EBV), and immune-oxidative biomarkers.

We examined 90 long COVID patients and ninety healthy controls. We measured serum IgA/IgM/IgG against HHV-6 and EBV and their deoxyuridine 5′-triphosphate nucleotidohydrolase (duTPase), SARS-CoV-2, and activin-A, C-reactive protein (CRP), advanced oxidation protein products (AOPP), and insulin resistance (HOMA2-IR).

Long COVID patients showed significant elevations in IgG/IgM-SARS-CoV-2, IgG/IgM-HHV-6, and HHV-6-duTPase, IgA/IgM-activin-A, CRP, AOPP, and HOMA2-IR. Neural network analysis yielded a highly significant predictive accuracy of 80.6% for the long COVID diagnosis (sensitivity: 78.9%, specificity: 81.8%, area under the ROC curve = 0.876); the topmost predictors were as follows: IGA-activin-A, IgG-HHV-6, IgM-HHV-6-duTPase, IgG-SARS-CoV-2, and IgM-HHV-6 (all positively) and a factor extracted from all IgA levels to all viral antigens (inversely). The top 5 predictors of affective symptoms due to long COVID were IgM-HHV-6-duTPase, IgG-HHV-6, CRP, education, IgA-activin-A (predictive accuracy of r = 0.636). The top 5 predictors of CFS due to long COVID were in descending order: CRP, IgG-HHV-6-duTPase, IgM-activin-A, IgM-SARS-CoV-2, and IgA-activin-A (predictive accuracy: r = 0.709).

Reactivation of HHV-6, SARS-CoV-2 persistence, and autoimmune reactions to activin-A combined with activated immune-oxidative pathways play a major role in the pathophysiology of long COVID as well as the severity of its affective symptoms and CFS.

Long coronavirus disease 2019 (LC) is a chronic sequel of acute COVID-19. The exact pathophysiology of the affective, chronic fatigue and physiosomatic symptoms (labelled as “physio-affective phenome”) of LC has remained elusive.

The current study aims to delineate the effects of oxygen saturation (SpO2) and body temperature during the acute phase on the physio-affective phenome of LC.

We recruited 120 LC patients and 36 controls. For all participants, we assessed the lowest SpO2 and peak body temperature during acute COVID-19, and the Hamilton Depression and Anxiety Rating Scale (HAMD/HAMA) and Fibro Fatigue (FF) scales 3–4 months later.

Lowered SpO2 and increased body temperature during the acute phase and female sex predict 60.7% of the variance in the physio-affective phenome of LC. Using unsupervised learning techniques, we were able to delineate a new endophenotype class, which comprises around 26.7% of the LC patients and is characterised by very low SpO2 and very high body temperature, and depression, anxiety, chronic fatigue, and autonomic and gastro-intestinal symptoms scores. Single latent vectors could be extracted from both biomarkers, depression, anxiety and FF symptoms or from both biomarkers, insomnia, chronic fatigue, gastro-intestinal and autonomic symptoms.

The newly constructed endophenotype class and pathway phenotypes indicate that the physio-affective phenome of LC is at least in part the consequence of the pathophysiology of acute COVID-19, namely the combined effects of lowered SpO2, increased body temperature and the associated immune-inflammatory processes and lung lesions.

There is strong comorbidity between atherosclerosis (ATS) and depression which is attributed to increased atherogenicity, insulin resistance (IR), and immune and oxidative stress.

To examine the role of the above pathways and mu-opioid receptor (MOR), β-endorphin levels, zinc, copper, vitamin D3, calcium, and magnesium in depression due to ATS/unstable angina (UA).

Biomarkers were assayed in 58 controls and 120 ATS patients divided into those with moderate and severe depression according to the Beck Depression Inventory-II (BDI-II) scores >19 and >29, respectively.

Neural network and logistic regression models showed that severe depression due to ATS/UA was best predicted by interleukin-6 (IL-6), UA, MOR, zinc, β-endorphin, calcium and magnesium, and that moderate depression was associated with IL-6, zinc, MOR, β-endorphin, UA, atherogenicity, IR, and calcium. Neural networks yielded a significant discrimination of severe and moderate depression with an area under the receiver operating curves of 0.831 and 0.931, respectively. Using Partial Least Squares path analysis, we found that 66.2% of the variance in a latent vector extracted from ATS/UA clinical features, and the BDI-II scores, atherogenicity, and IR could be explained by the regression on IL-6, IL-10, zinc, copper, calcium, MOR, and age. The BDI-II scores increased from controls to ATS to UA class III to UA class IV.

Immune activation, the endogenous opioid system, antioxidants, trace elements, and macrominerals modulate a common core shared by increased depressive symptoms, ATS, UA, atherogenicity, and IR.

Schizophrenia and deficit schizophrenia are accompanied by neurocognitive impairments. The aim of this study was to examine whether a general factor underpins impairments in key Cambridge Neuropsychological Test Automated Battery (CANTAB) probes, verbal fluency test (VFT), world list memory (WLM), True Recall, and mini mental state examination (MMSE).

We recruited 80 patients with schizophrenia and 40 healthy controls. All patients were assessed using CANTAB tests, namely paired-association learning, rapid visual information processing, spatial working memory, one touch stockings of Cambridge, intra/extradimensional set-shifting (IED), and emotional recognition test.

We found that a general factor, which is essentially unidimensional, underlies those CANTAB, VFT, WLM, True Recall, and MMSE scores. This common factor shows excellent psychometric properties and fits a reflective model and, therefore, reflects a general cognitive decline (G-CoDe) comprising deficits in semantic and episodic memory, recall, executive functions, strategy use, rule acquisition, visual sustained attention, attentional set-shifting, and emotional recognition. Partial least squares analysis showed that 40.5% of the variance in G-CoDe is explained by C-C motif ligand 11, IgA to tryptophan catabolites, and increased oxidative toxicity, and that G-CoDe explains 44.8% of the variance in a general factor extracted from psychosis, hostility, excitation, mannerism, negative symptoms, formal thought disorders, and psychomotor retardation, and 40.9% in quality-of-life scores. The G-CoDe is significantly greater in deficit than in nondeficit schizophrenia.

A common core shared by a multitude of neurocognitive impairments (G-CoDe) mediates the effects of neurotoxic pathways on the phenome of (deficit) schizophrenia.