Adjunctive use of anti-inflammatory drugs for schizophrenia: A meta-analytic investigation of randomized controlled trials

Neutrophil/lymphocyte ratio and cognitive performances in first-episode patients with schizophrenia and healthy controls

Abnormal immune and inflammatory responses are considered to contribute to schizophrenia (SZ). The neutrophil/lymphocyte ratio (NLR) is an inexpensive and reproducible marker of systemic inflammatory responses. Accumulating studies have demonstrated that NLR values are increased in SZ compared to healthy controls and closely related to clinical symptoms in antipsychotic-naïve first-episode SZ (ANFES) patients. However, to our knowledge, only one study has examined NLR in relation to neurocognition in 27 first-episode psychosis patients and 27 controls. This study aimed to examine the relationship of NLR values with cognitive performances in ANFES patients with a larger sample size. Whole blood cell counts were measured in ninety-seven ANFES patients and fifty-six control subjects. The neurocognitive functions of all subjects were measured by the repeatable battery for the assessment of neuropsychological status (RBANS). ANFES patients performed worse on cognition and had increased NLR values relative to healthy controls. In addition, increased NLR was negatively associated with cognitive functions in ANFES patients. Lymphocyte count was positively correlated with cognitive functions in patients. These findings suggest that the abnormal immune and inflammation system indicated by NLR may be involved in the cognitive functions in ANFES patients.

Metabolic complications of psychotropic medications in psychiatric disorders: Emerging role of de novo lipogenesis and therapeutic consideration

Although significant advances have been made in understanding the patho-physiology of psychiatric disorders (PDs), therapeutic advances have not been very convincing. While psychotropic medications can reduce classical symptoms in patients with PDs, their long-term use has been reported to induce or exaggerate various pre-existing metabolic abnormalities including diabetes, obesity and non-alcoholic fatty liver disease (NAFLD). The mechanism(s) underlying these metabolic abnormalities is not clear; however, lipid/fatty acid accumulation due to enhanced de novo lipogenesis (DNL) has been shown to reduce membrane fluidity, increase oxidative stress and inflammation leading to the development of the aforementioned metabolic abnormalities. Intriguingly, emerging evidence suggest that DNL dysregulation and fatty acid accumulation could be the major mechanisms associated with the development of obesity, diabetes and NAFLD after long-term treatment with psychotropic medications in patients with PDs. In support of this, several adjunctive drugs comprising of anti-oxidants and anti-inflammatory agents, that are used in treating PDs in combination with psychotropic medications, have been shown to reduce insulin resistance and development of NAFLD. In conclusion, the above evidence suggests that DNL could be a potential pathological factor associated with various metabolic abnormalities, and a new avenue for translational research and therapeutic drug designing in PDs.

Side effects and cognitive benefits of buspirone: A systematic review and meta-analysis

Buspirone, a 5-hydroxytryptamine 1A (5-HT1A) receptor agonist, has been investigated for its use in various diseases. However, knowledge about its side effects and potential cognitive benefits in different conditions is limited. Cognitive impairment is also a prevalent symptom in many diseases, yet effective treatments are still lacking. Therefore, to explore the potential side effects of buspirone and the possible cognitive benefits of buspirone, we conducted a comprehensive search of several databases, including PubMed, Embase, Web of Science, Cochrane Review, Cochrane Trial, and ClinicalTrials.gov, to identify eligible randomized clinical trials. Our primary outcome measures included both side effects (adverse events) and cognitive benefits. For continuous variables, we utilized effect size with a 95% confidence interval (CI), whereas for dichotomous variables, we used odds ratios (OR) with a 95% CI. In total, 16 studies were included in this analysis, with 13 studies reporting on buspirone's side effects and 4 studies focusing on cognitive tasks. In terms of side effects, buspirone exhibited a higher rate of dizziness (OR = 4.66, 95% CI: 2.07-10.47), constipation (OR = 4.11, 95% CI: 1.34-12.55), and gastric distress (OR = 1.97, 95% CI: 1.03-3.78) than the placebo group. Regarding cognitive functions, buspirone showed significant benefits (g = 0.20, 95% CI: 0.06-0.34) while the placebo did not. Subgroup analysis indicated superior performance in visual learning and memory (g = 0.49, 95% CI: 0.21-0.78), logical reasoning (g = 0.42, 95% CI: 0.14-0.71), and attention (g = 0.37, 95% CI: 0.13-0.61) when compared to placebo. Our findings indicated that participants in the buspirone group experienced side effects of dizziness, constipation, and gastric distress in different diseases. Despite these adverse events, however, buspirone demonstrated significant cognitive benefits, particularly in the domains of visual learning and memory, logical reasoning, and attention.

Circulating microRNA Profiles Identify a Patient Subgroup with High Inflammation and Severe Symptoms in Schizophrenia Experiencing Acute Psychosis

Schizophrenia is a complex and heterogenous psychiatric disorder. This study aimed to demonstrate the potential of circulating microRNAs (miRNAs) as a clinical biomarker to stratify schizophrenia patients and to enhance understandings of their heterogenous pathophysiology. We measured levels of 179 miRNA and 378 proteins in plasma samples of schizophrenia patients experiencing acute psychosis and obtained their Positive and Negative Syndrome Scale (PANSS) scores. The plasma miRNA profile revealed three subgroups of schizophrenia patients, where one subgroup tended to have higher scores of all the PANSS subscales compared to the other subgroups. The subgroup with high PANSS scores had four distinctively downregulated miRNAs, which enriched 'Immune Response' according to miRNA set enrichment analysis and were reported to negatively regulate IL-1β, IL-6, and TNFα. The same subgroup had 22 distinctively upregulated proteins, which enriched 'Cytokine-cytokine receptor interaction' according to protein set enrichment analysis, and all the mapped proteins were pro-inflammatory cytokines. Hence, the subgroup is inferred to have comparatively high inflammation within schizophrenia. In conclusion, miRNAs are a potential biomarker that reflects both disease symptoms and molecular pathophysiology, and identify a patient subgroup with high inflammation. These findings provide insights for the precision medicinal strategies for anti-inflammatory treatments in the high-inflammation subgroup of schizophrenia.

A double-blind, randomized controlled study of the effects of celecoxib on clinical symptoms and cognitive impairment in patients with drug-naïve first episode schizophrenia: pharmacogenetic impact of cyclooxygenase-2 functional polymorphisms

Chronic low-grade peripheral and central nervous system inflammation may have a role in the pathogenesis of schizophrenia (SCZ). Inhibition of cyclooxygenase-2 (COX2), the arachidonic acid pathway, may inhibit cytokine responses and minimize inflammation. In this study, we added the COX2 inhibitor celecoxib to risperidone monotherapy to examine its efficacy on clinical symptoms and cognitive deficits in drug-naïve first episode (DNFE) SCZ patients. First, we genotyped two polymorphisms (rs5275 and rs689466) in the COX-2 gene in a case-control study of 353 SCZ patients and 422 healthy controls. Ninety patients participated in a 12-week, double-blind, randomized, placebo-controlled trial of celecoxib 400 mg/day. We used the Positive and Negative Syndrome Scale (PANSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to assess clinical symptoms and cognition. Our results show that the COX2 rs5275 polymorphism was significantly correlated with SCZ and positive symptoms. After 12-week treatment, celecoxib significantly improved the PANSS total and three subscale scores of SCZ patients. Furthermore, patients with the rs5275 TT genotype had greater improvement in PANSS total score than patients carrying the C allele. However, no significant difference in RBANS total and subscale scores existed between the celecoxib and placebo groups at week 12. Our findings suggest that COX2 inhibitors may be promising therapeutics for clinical symptoms rather than cognitive impairment in first episode SCZ patients. COX2 rs5275 gene polymorphism may be implicated in the development and the efficacy of treating clinical symptoms in SCZ.Trial Registration Number: The trial was registered with www.clinicaltrials.gov (NCT00686140).

Inflammatory cerebrospinal fluid markers in schizophrenia spectrum disorders: A systematic review and meta-analysis of 69 studies with 5710 participants

BACKGROUND

There is increasing evidence of immune dysregulation and neuroinflammation occurring in schizophrenia. The aim of this study is to combine studies on routine CSF parameters, as well as cytokines and inflammatory proteins, in individuals with schizophrenia spectrum disorders.

METHODS

CSF parameters were summated and inverse variance meta-analyses using a random effects model were performed comparing mean difference or odds ratios. Between study heterogeneity was assessed using the I2 statistic. Quality assessment and sensitivity analyses were performed.

RESULTS

There were 69 studies of 5710 participants, including 3180 individuals with schizophrenia spectrum disorders. Averaged CSF parameters were within normal limits, however, between 3.1 % and 23.5 % of individual cases with schizophrenia spectrum disorders had an abnormal CSF result: Protein (abnormal in 23.5 % cases), albumin (in 18.5 %), presence of oligoclonal bands (in 9.3 %), white blood cell count (in 3.6 %), and IgG levels (3.1 %). Meta-analysis of 55 studies with non-psychiatric controls demonstrated a significant increase in CSF total protein (MD: 3.50, CI: 0.12-6.87), albumin ratio (MD: 0.55, CI: 0.02-0.09), white cell count (MD: 0.25, CI: 0.05-0.46), IL-6 (SMD: 0.53, CI: 0.29 to 0.77) and IL-8 (SMD: 0.56, CI: 0.11 to 1.01). Sensitivity analysis did not alter findings.

CONCLUSION

Abnormal CSF parameters, cytokines and inflammatory proteins were found in a significant proportion of individuals with schizophrenia spectrum disorders. This may indicate alterations to blood brain barrier function and permeability, CSF flow dynamics or neuroinflammation. Further research is needed to explore these potential mechanisms.

Chronic Treatment with Nigella sativa Oil Exerts Antimanic Properties and Reduces Brain Inflammation in Rats

Nigella sativa (NS) is a native herb consumed habitually in several countries worldwide, possessing manifold therapeutic properties. Among them, anti-inflammatory features have been reported, presumably relating to mechanisms involved in the nuclear factor kappa-B pathway, among others. Given the observed association between neuroimmune factors and mental illness, the primary aim of the present study was to examine the effects of chronic NS use on manic-like behavior in rats, as well as analyze levels of brain inflammatory mediators following NS intake. Using male and female rats, baseline tests were performed; thereafter, rats were fed either regular food (control) or NS-containing food (treatment) for four weeks. Following intervention, behavioral tests were induced (an open field test, sucrose consumption test, three-chamber sociality test, and amphetamine-induced hyperactivity test). Subsequently, brain samples were extracted, and inflammatory mediators were evaluated, including interleukin-6, leukotriene B4, prostaglandin E2, tumor necrosis factor-α, and nuclear phosphorylated-p65. Our findings show NS to result in a marked antimanic-like effect, in tandem with a positive modulation of select inflammatory mediators among male and female rats. The findings reinforce the proposed therapeutic advantages relating to NS ingestion.

Greater Choline-Containing Compounds and Myo-inositol in Treatment-Resistant Versus Responsive Schizophrenia: A 1H-Magnetic Resonance Spectroscopy Meta-analysis

BACKGROUND

The neurobiology of treatment-resistant schizophrenia (TRS) is poorly understood, and meta-analytic consensus regarding magnetic resonance spectroscopic profiles of glutamate, choline-containing compounds, myo-inositol, and other metabolites in the condition is lacking.

METHODS

In this meta-analysis, we examined published findings for N-acetylaspartate, choline-containing compounds (phosphocholine+glycerophosphocholine), myo-inositol, creatine+phosphocreatine, glutamate, and glutamate+glutamine in the anterior cingulate cortex and dorsal striatum in people with TRS versus non-TRS as well as TRS versus healthy control participants (HCs) and TRS versus ultra TRS (i.e., TRS with clozapine resistance). A MEDLINE search revealed 9 articles including 239 people with pooled TRS and ultra TRS, 59 with ultra TRS, 175 with non-TRS, and 153 (HCs) that met meta-analytic criteria.

RESULTS

Significant effects included higher anterior cingulate cortex phosphocholine+glycerophosphocholine and myo-inositol in the pooled TRS and ultra TRS group than in both the non-TRS group and HCs as well as higher dorsal striatal phosphocholine+glycerophosphocholine in ultra TRS versus HCs, but no differences in other regional metabolites.

CONCLUSIONS

The observed metabolite profile in TRS (higher phosphocholine+glycerophosphocholine and myo-inositol signal) is consistent with the hypothesis that TRS has a neuroinflammatory component, although this meta-analysis is not a critical test of that hypothesis. A similar profile is seen in healthy aging, which is known to involve increased neuroinflammation and glial activation. Because the overall number of datasets was low, however, results should be considered preliminary and highlight the need for additional studies of brain metabolites in TRS and their possible association with inflammatory processes.

Executive functioning trajectories and their prospective association with inflammatory biomarkers in schizophrenia and non-psychiatric comparison participants

BACKGROUND AND HYPOTHESIS

Cognitive change in people with schizophrenia (PwS) is challenging to assess, but important to understand. Previous studies with limited age ranges and follow-up were subject to practice effects. Controlling for practice effects in a well-established cohort, we examined executive functioning trajectories and their association with inflammatory biomarkers, hypothesizing that PwS will have worsening executive functioning over time compared to non-psychiatric comparison participants (NCs), predicted by higher baseline inflammation with a stronger relationship in PwS than NCs.

STUDY DESIGN

Executive functioning was assessed in 350 participants (n = 186 PwS, 164 NCs) at 12-16-month intervals (0 to 7 follow-up visits). Inflammatory biomarkers at baseline included high sensitivity C-Reactive Protein (hs-CRP), Interferon-gamma, Tumor Necrosis Factor (TNF)-alpha, and Interleukin(IL)-6, -8, and - 10. Executive functioning trajectories across diagnostic groups were estimated using a linear mixed-effects model controlling for age, sex, race/ethnicity, and education level, with additional models to assess prediction by baseline inflammation.

STUDY RESULTS

Over 4.4 years average follow-up, improvements in executive functioning were attenuated in PwS and older participants. Controlling for practice effects negated improvements, revealing declines among highly educated participants regardless of diagnosis. Higher baseline hs-CRP predicted worse executive functioning only among NCs, while TNF-alpha was predictive of change in all participants only after controlling for practice effects. Only the main effect of hs-CRP on executive function was significant after adjusting for multiple comparisons. None of the other inflammatory biomarkers predicted executive functioning or trajectories of performance among study participants.

CONCLUSIONS

Systemic inflammation as reflected by baseline inflammatory biomarker levels did not predict longitudinal declines in executive functioning. Additional studies examining the temporal dynamics of inflammation and cognition in PwS will help further clarify their relationship and associated mechanisms.

The Role of Total White Blood Cell Count in Antipsychotic Treatment for Patients with Schizophrenia

BACKGROUND

Total white blood cell count (TWBCc), an index of chronic and low-grade inflammation, is associated with clinical symptoms and metabolic alterations in patients with schizophrenia. The effect of antipsychotics on TWBCc, predictive values of TWBCc for drug response, and role of metabolic alterations require further study.

METHODS

Patients with schizophrenia were randomized to monotherapy with risperidone, olanzapine, quetiapine, aripiprazole, ziprasidone, perphenazine or haloperidol in a 6-week pharmacological trial. We repeatedly measured clinical symptoms, TWBCc, and metabolic measures (body mass index, blood pressure, waist circumference, fasting blood lipids and glucose). We used mixed-effect linear regression models to test whether TWBCc can predict drug response. Mediation analysis to investigate metabolic alteration effects on drug response.

RESULTS

At baseline, TWBCc was higher among patients previously medicated. After treatment with risperidone, olanzapine, quetiapine, perphenazine, and haloperidol, TWBCc decreased significantly (p < 0.05). Lower baseline TWBCc predicted greater reductions in Positive and Negative Syndrome Scale (PANSS) total and negative scores over time (p < 0.05). We found significant mediation of TWBCc for effects of waist circumference, fasting low-density lipoprotein cholesterol, and glucose on reductions in PANSS total scores and PANSS negative subscale scores (p < 0.05).

CONCLUSION

TWBCc is affected by certain antipsychotics among patients with schizophrenia, with decreases observed following short-term, but increases following long-term treatment. TWBCc is predictive of drug response, with lower TWBCc predicting better responses to antipsychotics. It also mediates the effects of certain metabolic measures on improvement of negative symptoms. This indicates that the metabolic state may affect clinical manifestations through inflammation.

Neuroinflammation and microglial expression in brains of social-isolation rearing model of schizophrenia

Schizophrenia is a psychiatric disorder with a global prevalence of approximately 0.45%. It is considered a mental illness, with negative symptoms, positive symptoms, and cognitive dysfunction. The outcomes of studies on the role of microglia and neuroinflammation have been conflicting. In addition, there is a poor understanding of the sex differences in microglial expression and neuroinflammation markers in the prefrontal cortex, hippocampus, and nucleus accumbens. Understanding the exact roles of neuroinflammation may guide the development of efficient therapeutic drugs that can address the negative, positive, and cognitive symptoms of the disease. We examined the effect of social isolation rearing on schizophrenia-related behaviours in male and female BALB/c mice. The social-isolation rearing protocol started on post-natal day (PND) 21, lasting for 35 days. Animals were assigned to four cohorts, consisting of five animals per group. On PND 56, animals were assessed for behavioural changes. We used enzyme-linked immunosorbent assays to investigate the expression of nuclear factor kappa B (NF-κB), tumour necrosis factor-α (TNF-α), and Interleukin-1β (IL-1β) in the hippocampus, nucleus accumbens, and prefrontal cortex. Immunohistochemistry was used to assess the expression of microglia in the three brain regions. Our study showed that isolation rearing led to increasing locomotion, heightened anxiety, depression, and a reduced percentage of prepulse inhibition. There was a significant increase (p < 0.05) in anxiety in the female isolation mice compared to male isolation mice. Furthermore, isolation rearing significantly increased microglia count (p < 0.05) in the hippocampus, nucleus accumbens, and prefrontal cortex, only in the male group. There was microglial hyper-activation as evident in the downregulation of CX3CR1 in both male and female social-isolation groups. Male social-isolation mice showed a significant increase (p < 0.05) in neuroinflammation markers only in the nucleus accumbens while the female social-isolation mice showed a significant increase (p < 0.05) in neuroinflammation markers in both the nucleus accumbens and hippocampus. The study showed that therapeutic interventions aimed at modulating CX3CR1 activity and reducing inflammation may be beneficial for patients with schizophrenia.

Inflammatory markers of symptomatic remission at 6 months in patients with first-episode schizophrenia

Neuroinflammation contributes to the pathophysiology of various mental illnesses including schizophrenia. We investigated peripheral inflammatory cytokines as a biomarker for predicting symptomatic remission in patients with first-episode schizophrenia. The study included 224 patients aged 15-60 years who fulfilled the criteria for schizophrenia spectrum disorder with a treatment duration ≤6 months. Serum levels of tumor necrosis factor (TNF) -α, interferon-γ, interleukin (IL)-1α, IL-1β, IL-6, IL-8, IL-10, and IL-12 were measured. Psychotic symptoms, depressive symptoms, and general functioning were assessed using the Positive and Negative Syndrome Scale, Beck Depression Inventory (BDI), Calgary Depression Scale for Schizophrenia, and Personal and Social Performance scale, respectively. Duration of untreated psychosis (DUP) was also recorded. We investigated the factors associated with remission for each sex in logistic regression analysis. In total, 174 patients achieved remission at the 6-month follow-up (females, 83.5%; males, 70.9%). Remission was associated with older age and lower BDI scores in male patients and with lower TNF-α levels and shorter DUP in female patients. Our findings suggest that peripheral inflammatory cytokines may impede early symptomatic remission in female patients with schizophrenia. In addition, depressive symptoms in males and long DUP in females may be poor prognostic factors for early remission in patients with first-episode psychosis.

Pentoxifylline as adjunctive therapy in cognitive deficits and symptoms of schizophrenia: A randomized double-blind placebo-controlled clinical trial

BACKGROUND

Due to the inflammatory factors in the pathophysiology of schizophrenia, Pentoxifylline, as anti-inflammatory medication, seems to improve the symptoms of schizophrenia. This study aims to evaluate the efficacy of Pentoxifylline as an adjunctive therapy on cognitive deficits and symptoms of schizophrenia.

METHODS

This randomized double-blind placebo-controlled clinical trial was conducted on 52 patients diagnosed with chronic schizophrenia. All patients were divided into two, treatment and control groups. They received a 400 mg dose of Pentoxifylline and the placebo in the treatment and control groups, respectively, twice a day for 8 weeks. Then, they were tested with the Positive and Negative Syndrome Scale (PANSS), Wisconsin Card Sorting Test (WCST), digit span, Stroop test, and Rey Auditory and Verbal Learning Test at baseline and the end of the weeks 4 and 8. Data analysis was done by Kolmogorov-Smirnov test, t-test, Mann-Whitney test, chi-square test, and generalized estimating equation model.

RESULTS

After analyzing the data, it was revealed that the positive symptoms of PANSS, the number of errors in the incongruent Stroop test, and reaction time in the congruent Stroop test were significantly lower in the treatment group (p < 0.05). Moreover, the number of categories of WCST was significantly higher in the treatment group (p < 0.05). There was no statistically significant difference in other parameters between the control and treatment groups (p > 0.05).

CONCLUSIONS

As evidenced by the results of this study, Pentoxifylline can help alleviate schizophrenia cognitive deficits and can reduce psychotic symptoms. Therefore, it can potentially be useful for schizophrenia treatment.

Adjunctive agents to antipsychotics in schizophrenia: a systematic umbrella review and recommendations for amino acids, hormonal therapies and anti-inflammatory drugs

QUESTION

This umbrella review and guidelines aimed to provide evidence to support the rational choice of selected adjunctive therapies for schizophrenia.

STUDY SELECTION AND ANALYSIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and World Federation of Societies of Biological Psychiatry (WFSBP)-grading recommendations, 63 randomised control trials (RCTs) (of which 4219 unique participants have completed the RCTs) and 29 meta-analyses were analysed.

FINDINGS

Provisional recommendations (WFSBP-grade 1) could be made for two molecules in augmentation to antipsychotics: (1) N-acetyl-cysteine (NAC, 1200-3600 mg/day, for >12 consecutive weeks) in improving negative symptoms, general psychopathology (positive and negative syndrome scale for schizophrenia (PANSS) general psychopathology factor (G)-G subscale), with the RCTs with the longer duration showing the most robust findings; (2) polyunsaturated fatty acids (3000 mg/day of eicosapentaenoic acid, for >12 weeks) in improving general psychopathology. Weaker recommendations (ie, WFSBP-grade 2) could be drawn for sarcosine (2 g/day) and minocycline (200-300 mg/day) for improving negative symptoms in chronic schizophrenia (not early schizophrenia), and NAC for improving positive symptoms and cognition. Weak recommendations are not ready for clinical practice. There is provisional evidence that oestrogens and raloxifene are effective in some patients, but further research is needed to determine their benefit/risk ratio.

CONCLUSIONS

The results of this umbrella review should be interpreted with caution as the number of RCTs included in the meta-analyses was generally small and the effect sizes were weak or medium. For NAC, two RCTs with low risk of bias have provided conflicting results and the WFSBP-grade recommendation included also the results of meta-analyses. These drugs could be provisionally prescribed for patients for whom no other treatments have been effective, but they should be discontinued if they prove ineffective.

A pilot study to examine the association between COX-2 rs5275 polymorphism and the response to repetitive transcranial stimulation in schizophrenia

High frequency (HF)-rTMS has been shown to improve cognitive functions in patients with schizophrenia (SCZ). This study aimed to investigate whether COX-2 rs5275 variants were associated with cognitive improvements following rTMS treatment in patients with SCZ. Forty-eight hospitalized patients with SCZ were assigned to the neuronavigation HF-rTMS group and 28 patients to the sham group over left DLPFC for 1 month. Cognitive function was evaluated using the repeatable battery for the assessment of neuropsychological status (RBANS) at weeks 0 and 4. COX-2 rs5275 polymorphism was genotyped by a technician. At baseline, C allele carriers showed better cognitive performance relative to patients with TT homozygote. Additionally, C allele carriers had greater improvement in memory from the follow-up to baseline following rTMS stimulation, while patients with the TT genotype showed no significant improvement in memory index. More importantly, we found that COX-2 rs5275 was correlated with the response to rTMS after controlling for the covariates. This study data indicate that COX-2 rs5275 was associated with improvements in immediate memory after HF-rTMS treatment in patients with SCZ. rTMS shows an effect on memory only in C allele carriers, but not in those with the TT genotype.

The Relationship of Cognitive Dysfunction with Inflammatory Markers and Carotid Intima Media Thickness in Schizophrenia

OBJECTIVES

Schizophrenia is a devastating and chronic mental disorder that affects 1% of the population worldwide. It is also associated with cognitive dysfunction and cardiovascular risk factors. The aim of this study is to investigate the relationship between cognitive impairment and some inflammatory markers and carotid intima-media thickness (CIMT) in schizophrenia.

METHODS

The participants of this study were 51 schizophrenia and 57 healthy controls (HC). The Positive and Negative Syndrome Scale (PANSS) was used for severity of illness, and the Montreal Cognitive Assessment Scale (MoCA) was used for cognitive functioning. The MoCA scores, some biochemical and inflammatory markers, and CIMT were compared between schizophrenia and HC groups.

RESULTS

Of the patients with schizophrenia, 11 were women (21.6%), and 40 were men (78.4%). MoCA scores were lower, and levels of NLR, MLR, PLR, SII, CRP, ESR, and CIMT were higher in schizophrenia compared to the HC group (respectively; p < 0.001, p < 0.001, p = 0.035, p = 0.008, p = 0.002, p < 0.001, p < 0.001, p < 0.001). In the schizophrenia group, there was no correlation between MoCA and inflammatory markers. MoCA and CIMT had a significant negative and moderate correlation (p < 0.001).

CONCLUSIONS

This is the first study to show the relationship between cognitive impairment and CIMT in schizophrenia. In this study, NLR, MLR, PLR, SII, CRP, and ESR markers were higher in schizophrenia compared to HC, indicating inflammation. Our finding of elevated CIMT in schizophrenia suggests that there may be an atherosclerotic process along with the inflammatory process. The finding of a positive correlation between cognitive impairment and CIMT may be promising for new therapies targeting the atherosclerotic process in the treatment of cognitive impairment.

Mitochondrial cytochrome P450 1B1 is involved in pregnenolone synthesis in human brain cells

Neurosteroids, which are steroids synthesized by the nervous system, can exert neuromodulatory and neuroprotective effects via genomic and nongenomic pathways. The neurosteroid and major steroid precursor pregnenolone has therapeutical potential in various diseases, such as psychiatric and pain disorders, and may play important roles in myelination, neuroinflammation, neurotransmission, and neuroplasticity. Although pregnenolone is synthesized by CYP11A1 in peripheral steroidogenic organs, our recent study showed that pregnenolone must be synthesized by another mitochondrial cytochrome P450 (CYP450) enzyme other than CYP11A1 in human glial cells. Therefore, we sought to identify the CYP450 responsible for pregnenolone production in the human brain. Upon screening for CYP450s expressed in the human brain that have mitochondrial localization, we identified three enzyme candidates: CYP27A1, CYP1A1, and CYP1B1. We found that inhibition of CYP27A1 through inhibitors and siRNA knockdown did not negatively affect pregnenolone synthesis in human glial cells. Meanwhile, treatment of human glial cells with CYP1A1/CYP1B1 inhibitors significantly reduced pregnenolone production in the presence of 22(R)-hydroxycholesterol. We performed siRNA knockdown of CYP1A1 or CYP1B1 in human glial cells and found that only CYP1B1 knockdown significantly decreased pregnenolone production. Furthermore, overexpression of mitochondria-targeted CYP1B1 significantly increased pregnenolone production under basal conditions and in the presence of hydroxycholesterols and low-density lipoprotein. Inhibition of CYP1A1 and/or CYP1B1 via inhibitors or siRNA knockdown did not significantly reduce pregnenolone synthesis in human adrenal cortical cells, implying that CYP1B1 is not a major pregnenolone-producing enzyme in the periphery. These data suggest that mitochondrial CYP1B1 is involved in pregnenolone synthesis in human glial cells.

Is It Time for a Paradigm Shift in the Treatment of Schizophrenia? The Use of Inflammation-Reducing and Neuroprotective Drugs-A Review

Comprehending the pathogenesis of schizophrenia represents a challenge for global mental health. To date, although it is evident that alterations in dopaminergic, serotonergic, and glutamatergic neurotransmission underlie the clinical expressiveness of the disease, neuronal disconnections represent only an epiphenomenon. In recent years, several clinical studies have converged on the hypothesis of microglia hyperactivation and a consequent neuroinflammatory state as a pathogenic substrate of schizophrenia. Prenatal, perinatal, and postnatal factors can cause microglia to switch from M2 anti-inflammatory to M1 pro-inflammatory states. A continuous mild neuroinflammatory state progressively leads to neuronal loss, a reduction in dendritic spines, and myelin degeneration. The augmentation of drugs that reduce neuroinflammation to antipsychotics could be an effective therapeutic modality in managing schizophrenia. This review will consider studies in which drugs with anti-inflammatory and neuroprotective properties have been used in addition to antipsychotic treatment in patients with schizophrenia.

Minocycline as Treatment for Psychiatric and Neurological Conditions: A Systematic Review and Meta-Analysis

Minocycline has anti-inflammatory, antioxidant, and anti-apoptotic properties that explain the renewed interest in its use as an adjunctive treatment for psychiatric and neurological conditions. Following the completion of several new clinical trials using minocycline, we proposed an up-to-date systematic review and meta-analysis of the data available. The PICO (patient/population, intervention, comparison and outcomes) framework was used to search 5 databases aiming to identify randomized controlled trials that used minocycline as an adjunctive treatment for psychiatric and neurological conditions. Search results, data extraction, and risk of bias were performed by two independent authors for each publication. Quantitative meta-analysis was performed using RevMan software. Literature search and review resulted in 32 studies being included in this review: 10 in schizophrenia, 3 studies in depression, and 7 in stroke, with the benefit of minocycline being used in some of the core symptoms evaluated; 2 in bipolar disorder and 2 in substance use, without demonstrating a benefit for using minocycline; 1 in obsessive-compulsive disorder, 2 in brain and spinal injuries, 2 in amyotrophic lateral sclerosis, 1 in Alzheimer’s disease, 1 in multiple systems atrophy, and 1 in pain, with mixes results. For most of the conditions included in this review the data is still limited and difficult to interpret, warranting more well-designed and powered studies. On the other hand, the studies available for schizophrenia seem to suggest an overall benefit favoring the use of minocycline as an adjunctive treatment.

MicroRNA schizophrenia: Etiology, biomarkers and therapeutic targets

The three sets of symptoms associated with schizophrenia-positive, negative, and cognitive-are burdensome and have serious effects on public health, which affects up to 1% of the population. It is now commonly believed that in addition to the traditional dopaminergic mesolimbic pathway, the etiology of schizophrenia also includes neuronal networks, such as glutamate, GABA, serotonin, BDNF, oxidative stress, inflammation and the immune system. Small noncoding RNA molecules called microRNAs (miRNAs) have come to light as possible participants in the pathophysiology of schizophrenia in recent years by having an impact on these systems. These small RNAs regulate the stability and translation of hundreds of target transcripts, which has an impact on the entire gene network. There may be improved approaches to treat and diagnose schizophrenia if it is understood how these changes in miRNAs alter the critical related signaling pathways that drive the development and progression of the illness.

Efficacy and safety of adjunctive therapy with fingolimod in patients with schizophrenia: A randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

Studies have suggested that fingolimod, a sphingosine-1-phosphate receptor modulator, exerts neuroprotective and anti-inflammatory effects. Although fingolimod is approved for the treatment of relapsing-remitting multiple sclerosis, limited studies have investigated its effects in patients with schizophrenia. This study investigated the efficacy and safety of fingolimod adjuvant to risperidone in schizophrenia treatment.

METHODS

This eight-week, randomized, double-blinded, placebo-controlled trial included 80 (clinical trials registry code: IRCT20090117001556N137) patients with chronic schizophrenia. Participants were assigned to two equal arms and received risperidone plus either fingolimod (0.5 mg/day) or a matched placebo. The positive and negative symptom scale (PANSS) was used to measure and compare the effectiveness of treatment strategies at baseline and weeks 2, 4, 6, and 8. Treatment side effects were also compared.

RESULTS

Seventy participants completed the trial (35 in each arm). The baseline characteristics of the groups were comparable (P-value > 0.05). There were significant time-treatment interaction effects on negative symptoms (P-value = 0.003), general symptoms (P-value = 0.037), and the PANSS total score (P-value = 0.035), suggesting greater improvement in symptoms following the fingolimod adjuvant therapy. In contrast, the longitudinal changes in positive and depressive symptoms were similar between the groups (P-values > 0.05). Regarding the safety of treatments, there were no differences in extrapyramidal symptoms [assessed by the extrapyramidal symptom rating scale (ESRS)] or frequency of other complications between the fingolimod and the placebo groups (P-values > 0.05).

CONCLUSIONS

This study indicated that fingolimod is a safe and effective adjuvant agent for schizophrenia treatment. However, further clinical trials are required to suggest extensive clinical application.

Depression trajectories and cytokines in schizophrenia spectrum disorders - A longitudinal observational study

Depression occurs frequently in all phases of schizophrenia spectrum disorders. Altered activity in the immune system is seen in both depression and schizophrenia. We aimed to uncover depressive trajectories in a sample of 144 adult individuals with schizophrenia spectrum disorders followed for one year, in order to identify possible cytokine profile differences. Patients were assessed longitudinally with the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS), where a score above 6 predicts depression. The serum cytokine concentrations for tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, IL-12p70 and IL-17A were measured using immunoassays. Latent growth curve models, multilevel models and latent class growth analysis (LCGA) were applied. The LCGA model supported three latent classes (trajectories) with differing CDSS profiles during the one-year follow-up: a high CDSS group (40.8 % of participants), a moderate CDSS group (43.9 %) and a low CDSS group (15.3 %). Five single PANSS items predicted affiliation to depressive trajectory: hallucinations, difficulty in abstract thinking, anxiety, guilt feelings and tension. In the high CDSS group, despite diminishing psychotic symptoms, depressive symptoms persisted throughout one year. The pro-inflammatory cytokines IFN-γ, IL-1β and TNF-α were differentially distributed between the depressive trajectories, although levels remained remarkably stable throughout 12 months. Significant changes were found for the anti-inflammatory cytokine IL-10 at baseline with an accompanying difference in change over time. More research is required to optimize future treatment stratification and investigate the contribution of inflammation in depressed patients with schizophrenia spectrum disorders.

The effect of lansoprazole on MK-801-induced schizophrenia-like behaviors in mice

As a heterogeneous disorder, schizophrenia is known to be associated with neuroinflammation. A recent study showed that several cytokines are higher in the plasma and cerebrospinal fluid of schizophrenia patients. Lansoprazole, a proton pump inhibitor used for treating erosive esophagitis, has been reported to reduce INF-γ-induced neurotoxicity and decrease inflammatory cytokines including IL-1β, IL-6, and TNF-α. These findings persuaded us to examine whether lansoprazole ameliorates schizophrenia-like symptoms. The schizophrenia mouse model was induced by the acute administration of MK-801, an NMDA receptor antagonist. Sensorimotor gating, Barnes maze, and social novelty preference tests were conducted to evaluate schizophrenia-like behaviors. We found that lansoprazole (0.3, 1, or 3 mg/kg) ameliorated sensorimotor gating deficits, spatial learning, and social deficits caused by MK-801 treatment (0.2 mg/kg). The catalepsy test, balance beam test, and rotarod test were performed to reveal the adverse effects of lansoprazole on motor coordination. The behavioral results indicated that lansoprazole did not result in any motor function deficits. Moreover, lansoprazole decreased inflammatory cytokines including IL-6 and TNF-α only in the cortex, but not in the hippocampus. Collectively, these results suggest that lansoprazole could be a potential candidate for treating schizophrenia patients who suffer from sensorimotor gating deficits or social disability without any motor-related adverse effects.

Taurine, an essential β-amino acid insulates against ketamine-induced experimental psychosis by enhancement of cholinergic neurotransmission, inhibition of oxidative/nitrergic imbalances, and suppression of COX-2/iNOS immunoreactions in mice

Cholinergic, oxidative, nitrergic alterations, and neuroinflammation are some key neuropathological features common in schizophrenia disease. They involve complex biological processes that alter normal behavior. The present treatments used in the management of the disorder remain ineffective together with some serious side effects as one of their setbacks. Taurine is a naturally occurring essential β-amino acid reported to elicit antipsychotic property in first episode psychosis in clinical setting, thus require preclinical investigation. Hence, we set out to investigate the effects of taurine in the prevention and reversal of ketamine-induced psychotic-like behaviors and the associated putative neurobiological mechanisms underlying its effects. Adult male Swiss mice were sheared into three separate cohorts of experiments (n = 7): drug alone, preventive and reversal studies. Treatments consisted of saline (10 mL/kg/p.o./day), taurine (50 and 100 mg/kg/p.o./day) and risperidone (0.5 mg/kg/p.o./day) with concomitant ketamine (20 mg/kg/i.p./day) injections between days 8-14, or 14 days entirely. Behavioral hyperactivity, despair, cognitive impairment, and catalepsy were measured. Brain oxidative/nitrergic imbalance, immunoreactivity (COX-2 and iNOS), and cholinergic markers were determined in the striatum, prefrontal-cortex, and hippocampus. Taurine abates ketamine-mediated psychotic-like episodes without cataleptogenic potential. Taurine attenuated ketamine-induced decrease in glutathione, superoxide-dismutase and catalase levels in the striatum, prefrontal-cortex and hippocampus. Also, taurine prevented and reversed ketamine-mediated elevation of malondialdehyde, nitrite contents, acetylcholinesterase activity, and suppressed COX-2 and iNOS expressions in a brain-region dependent manner. Conclusively, taurine insulates against ketamine-mediated psychotic phenotype by normalizing brain central cholinergic neurotransmissions, oxidative, nitrergic and suppression of immunoreactive proteins in mice brains.

Cytokines as Potential Biomarkers of Clinical Characteristics of Schizophrenia

Immune activation plays a major role in the pathogenesis of schizophrenia, as confirmed by many studies, systematic reviews, and meta-analyses. The important role of neuroinflammation in the formation of the relation between impaired neurobiological processes and schizophrenia psychopathology is being actively discussed. We quantified serum concentrations of 22 cytokines in 236 patients with schizophrenia and 103 mentally and somatically healthy individuals by a multiplex assay. We found higher TGF-α (p = 0.014), IFN-γ (p = 0.036), IL-5 (p < 0.001), IL-6 (p = 0.047), IL-8 (p = 0.005), IL-10 (p <0.001), IL-15 (p = 0.007), IL-1RA (p = 0.007), and TNF-α (p < 0.001) levels in patients with schizophrenia than in healthy individuals. Subgroup analysis revealed a much greater number of statistically significant differences in cytokine levels among females than among males. Patients with a continuous course of schizophrenia showed statistically significantly higher levels of IL-12p70 (p = 0.019), IL-1α (p = 0.046), and IL-1β (p = 0.035) compared with patients with an episodic course. Most cytokines were positively correlated with positive, general, and total PANSS scores. In patients with a duration of schizophrenia of 10 years or more, the level of IL-10 was higher than that in patients with a disease duration of 5 years or less (p = 0.042). Thus, an imbalance in cytokines was revealed in patients with schizophrenia, depending on sex and clinical characteristics of the disease.

Effects of add-on Celecoxib treatment on patients with schizophrenia spectrum disorders and inflammatory cytokine profile trial (TargetFlame): study design and methodology of a multicentre randomized, placebo-controlled trial

Neuroinflammation has been proposed to impact symptomatology in patients with schizophrenia spectrum disorders. While previous studies have shown equivocal effects of treatments with add-on anti-inflammatory drugs such as Aspirin, N-acetylcysteine and Celecoxib, none have used a subset of prospectively recruited patients exhibiting an inflammatory profile. The aim of the study is to evaluate the efficacy and safety as well as the cost-effectiveness of a treatment with 400 mg Celecoxib added to an ongoing antipsychotic treatment in patients with schizophrenia spectrum disorders exhibiting an inflammatory profile. The “Add-on Celecoxib treatment in patients with schizophrenia spectrum disorders and inflammatory cytokine profile trial (TargetFlame)” is a multicentre randomized, placebo-controlled phase III investigator-initiated clinical trial with the following two arms: patients exhibiting an inflammatory profile receiving either add-on Celecoxib 400 mg/day or add-on placebo. A total of 199 patients will be assessed for eligibility by measuring blood levels of three pro-inflammatory cytokines, and 109 patients with an inflammatory profile, i.e. inflamed, will be randomized, treated for 8 weeks and followed-up for additional four months. The primary endpoint will be changes in symptom severity as assessed by total Positive and Negative Syndrome Scale (PANSS) score changes from baseline to week 8. Secondary endpoints include various other measures of psychopathology and safety. Additional health economic analyses will be performed. TargetFlame is the first study aimed at evaluating the efficacy, safety and cost-effectiveness of the antiphlogistic agent Celecoxib in a subset of patients with schizophrenia spectrum disorders exhibiting an inflammatory profile. With TargetFlame, we intended to investigate a novel precision medicine approach towards anti-inflammatory antipsychotic treatment augmentation using drug repurposing.

Clinical trial registration:http://www.drks.de/DRKS00029044 and https://trialsearch.who.int/Trial2.aspx?TrialID=DRKS00029044

Latent infections, coronavirus disease 2019 and psychiatric disorders: The friend of my enemy

Recent reports revealed an increased rate of hospitalization and mortality of coronavirus disease 2019 (COVID-19) among patients with psychiatric disorders. On the other hand, there is a link between latent infections, including Toxoplasma gondii, herpes simplex virus type 1 (HSV-1) and cytomegalovirus (CMV) with psychiatric disorders. We individually assessed data regarding 1) the mortality rate of COVID-19 among individuals with psychiatric disorders; 2) the association of latent infections in COVID-19 patients and 3) the association between latent infections and psychiatric disorders. We developed the hypothesis that latent infection could increase the risk of severe COVID-19 among patients with psychiatric disorders. Cumulative evidence proposed that infection with toxoplasmosis, CMV and HSV-1 could increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-Co-V2) infections among patients with psychiatric disorders probably by induction of hyperinflammatory conditions. These infections are also associated with hyperinflammation and T cell exhaustion, which has also been observed in both schizophrenia and COVID-19. This hypothesis provides new insights into the role of latent infections in increasing the mortality rates of COVID-19 among individuals with psychiatric disorders. Strategies for screening, early diagnosis and treatment of these infections could be recommended for COVID-19 patients with a background of psychiatric disorders.

Management of cognitive and negative symptoms in schizophrenia

Currently available antipsychotics provide only modest benefit in managing the cognitive and negative symptoms of schizophrenia even though these symptoms are often the most impairing in patients' daily lives. Certain antipsychotics may have slight benefits over others, and several nonpharmacologic and pharmacologic adjunctive treatments have been evaluated in recent clinical trials. Recently published meta-analyses and clinical studies of such treatments are reviewed. Potential strategies to manage cognitive and negative symptoms, including deprescribing of medications that may exacerbate these symptoms, are described using theoretical case examples.

Cytokine Imbalance as a Biomarker of Treatment-Resistant Schizophrenia

Treatment-resistant schizophrenia (TRS) is an important and unresolved problem in biological and clinical psychiatry. Approximately 30% of cases of schizophrenia (Sch) are TRS, which may be due to the fact that some patients with TRS may suffer from pathogenetically “non-dopamine” Sch, in the development of which neuroinflammation is supposed to play an important role. The purpose of this narrative review is an attempt to summarize the data characterizing the patterns of production of pro-inflammatory and anti-inflammatory cytokines during the development of therapeutic resistance to APs and their pathogenetic and prognostic significance of cytokine imbalance as TRS biomarkers. This narrative review demonstrates that the problem of evaluating the contribution of pro-inflammatory and anti-inflammatory cytokines to maintaining or changing the cytokine balance can become a new key in unlocking the mystery of “non-dopamine” Sch and developing new therapeutic strategies for the treatment of TRS and psychosis in the setting of acute and chronic neuroinflammation. In addition, the inconsistency of the results of previous studies on the role of pro-inflammatory and anti-inflammatory cytokines indicates that the TRS biomarker, most likely, is not the serum level of one or more cytokines, but the cytokine balance. We have confirmed the hypothesis that cytokine imbalance is one of the most important TRS biomarkers. This hypothesis is partially supported by the variable response to immunomodulators in patients with TRS, which were prescribed without taking into account the cytokine balance of the relation between serum levels of the most important pro-inflammatory and anti-inflammatory cytokines for TRS.

Montelukast induces beneficial behavioral outcomes and reduces inflammation in male and female rats

Background

Accumulative data links inflammation and immune dysregulation to the pathophysiology of mental disorders; little is known regarding leukotrienes’ (LTs) involvement in this process. Circumstantial evidence suggests that treatment with leukotriene modifying agents (LTMAs) such as montelukast (MTK) may induce adverse neuropsychiatric events. Further methodic evaluation is warranted.

Objective

This study aims to examine behavioral effects, as well as inflammatory mediator levels of chronic MTK treatment in male and female rats.

Methods

Depression-like phenotypes were induced by exposing male and female rats to a chronic unpredictable mild stress (CUMS) protocol for four weeks. Thereafter, rats were treated (intraperitoneally) once daily, for two weeks, with either vehicle (dimethyl sulfoxide 0.2 ml/rat) or 20 mg/kg MTK. Following treatment protocols, behavioral tests were conducted and brain regions were evaluated for inflammatory mediators including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and prostaglandin (PG) E2.

Results

Overall, MTK did not invoke negative behavioral phenotypes (except for an aggression-inducing effect in males). Numerous positive behavioral outcomes were observed, including reduction in aggressive behavior in females and reduced manic/hyperactive-like behavior and increased sucrose consumption (suggestive of antidepressant-like effect) in males. Furthermore, in control males, MTK increased IL-6 levels in the hypothalamus and TNF-α in the frontal cortex, while in control females it generated a robust anti-inflammatory effect. In females that were subjected to CUMS, MTK caused a prominent reduction in TNF-α and IL-6 in brain regions, whereas in CUMS-subjected males its effects were inconsistent.

Conclusion

Contrary to prior postulations, MTK may be associated with select beneficial behavioral outcomes. Additionally, MTK differentially affects male vs. female rats in respect to brain inflammatory mediators, plausibly explaining the dissimilar behavioral phenotypes of sexes under MTK treatment.

Association between Peripheral Inflammatory Cytokines and Cognitive Function in Patients with First-Episode Schizophrenia

In this study, we investigated the impact of inflammatory cytokines on the cognitive performance of patients with schizophrenia. The included patients met the criteria for schizophrenia spectrum disorder and were aged between 15 and 40 years, with a duration of illness ≤1 year. Plasma tumor necrosis factor (TNF)-α; interferon-γ; and interleukin (IL)-1β, IL-6, IL-8, IL-10, and IL-12 levels were measured. A computerized neurocognitive battery, measures for social cognitive function, and clinical measures were administered. A total of 174 patients with first-episode psychosis were enrolled. The TNF-α level was negatively correlated with scores on the digit span, verbal learning, and Wisconsin card sorting tests, and the number of correct responses on the continuous performance test (CR-CPT), whereas a positive correlation was detected with the trail making test (TMT)-B time. The interferon-γ level was negatively correlated with performance on the false belief and visual learning tests. The IL-1β level was positively correlated with the TMT-A time and CPT reaction time, whereas it was negatively correlated with the CR-CPT and performance on the visual learning and social cognitive tests. The IL-12 level was negatively correlated with the CR-CPT and false belief test. Our results suggest that proinflammatory cytokines are associated with cognitive impairment in patients with schizophrenia.

The Antioxidant N-Acetyl-L-Cysteine Restores the Behavioral Deficits in a Neurodevelopmental Model of Schizophrenia Through a Mechanism That Involves Nitric Oxide

The disruption of neurodevelopment is a hypothesis for the emergence of schizophrenia. Some evidence supports the hypothesis that a redox imbalance could account for the developmental impairments associated with schizophrenia. Additionally, there is a deficit in glutathione (GSH), a main antioxidant, in this disorder. The injection of metilazoximetanol acetate (MAM) on the 17th day of gestation in Wistar rats recapitulates the neurodevelopmental and oxidative stress hypothesis of schizophrenia. The offspring of rats exposed to MAM treatment present in early adulthood behavioral and neurochemical deficits consistent with those seen in schizophrenia. The present study investigated if the acute and chronic (250 mg/kg) treatment during adulthood with N-acetyl-L-cysteine (NAC), a GSH precursor, can revert the behavioral deficits [hyperlocomotion, prepulse inhibition (PPI), and social interaction (SI)] in MAM rats and if the NAC-chronic-effects could be canceled by L-arginine (250 mg/kg, i.p, for 5 days), nitric oxide precursor. Analyses of markers involved in the inflammatory response, such as astrocytes (glial fibrillary acid protein, GFAP) and microglia (binding adapter molecule 1, Iba1), and parvalbumin (PV) positive GABAergic, were conducted in the prefrontal cortex [PFC, medial orbital cortex (MO) and prelimbic cortex (PrL)] and dorsal and ventral hippocampus [CA1, CA2, CA3, and dentate gyrus (DG)] in rats under chronic treatment with NAC. MAM rats showed decreased time of SI and increased locomotion, and both acute and chronic NAC treatments were able to recover these behavioral deficits. L-arginine blocked NAC behavioral effects. MAM rats presented increases in GFAP density at PFC and Iba1 at PFC and CA1. NAC increased the density of Iba1 cells at PFC and of PV cells at MO and CA1 of the ventral hippocampus. The results indicate that NAC recovered the behavioral deficits observed in MAM rats through a mechanism involving nitric oxide. Our data suggest an ongoing inflammatory process in MAM rats and support a potential antipsychotic effect of NAC.

Schizophrenia and Inflammation Research: A Bibliometric Analysis

Background

Schizophrenia (SCZ) is a severe psychiatric disorder that involves inflammatory processes. The aim of this study was to explore the field of inflammation-related research in SCZ from a bibliometric perspective.

Methods

Regular and review articles on SCZ- and inflammation-related research were obtained from the Web of Science Core Collection (WOSCC) database from its inception to February 19, 2022. R package "bibliometrix" was used to summarize the main findings, count the occurrences of the top keywords, visualize the collaboration network between countries, and generate a three-field plot. VOSviewer software was applied to conduct both co-authorship and co-occurrence analyses. CiteSpace was used to identify the top references and keywords with the strongest citation burst.

Results

A total of 3,596 publications on SCZ and inflammation were included. Publications were mainly from the USA, China, and Germany. The highest number of publications was found in a list of relevant journals. Apart from "schizophrenia" and "inflammatory", the terms "bipolar disorder," "brain," and "meta-analysis" were also the most frequently used keywords.

Conclusions

This bibliometric study mapped out a fundamental knowledge structure consisting of countries, institutions, authors, journals, and articles in the research field of SCZ and inflammation over the past 30 years. The results provide a comprehensive perspective about the wider landscape of this research area.

White matter microstructure and the clinical risk for psychosis: A diffusion tensor imaging study of individuals with basic symptoms and at ultra-high risk

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This DTI cross-sectional study compared UHR, basic symptom & control groups (n = 112).

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The splenium of UHR individuals exhibited differences in fractional anisotropy (FA).

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Basic symptoms alone were not associated with white matter microstructure changes.

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Large differences in FA & radial diffusivity were found in converters to psychosis.

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Regional FA was inversely correlated with the general psychopathology domain.

Background

Widespread white matter abnormalities are a frequent finding in chronic schizophrenia patients. More inconsistent results have been provided by the sparser literature on at-risk states for psychosis, i.e., emerging subclinical symptoms. However, considering risk as a homogenous construct, an approach of earlier studies, may impede our understanding of neuro-progression into psychosis.

Methods

An analysis was conducted of 3-Tesla MRI diffusion and symptom data from 112 individuals (mean age, 21.97 ± 4.19) within two at-risk paradigm subtypes, only basic symptoms (n = 43) and ultra-high risk (n = 37), and controls (n = 32). Between-group comparisons (involving three study groups and further split based on the subsequent transition to schizophrenia) of four diffusion-tensor-imaging-derived scalars were performed using voxelwise tract-based spatial statistics, followed by correlational analyses with Structured Interview for Prodromal Syndromes responses.

Results

Relative to controls, fractional anisotropy was lower in the splenium of the corpus callosum of ultra-high-risk individuals, but only before stringent multiple-testing correction, and negatively correlated with General Symptom severity among at-risk individuals. At-risk participants who transitioned to schizophrenia within 3 years, compared to those that did not transition, had more severe WM differences in fractional anisotropy and radial diffusivity (particularly in the corpus callosum, anterior corona radiata, and motor/sensory tracts), which were even more extensive compared to healthy controls.

Conclusions

These findings align with the subclinical symptom presentation and more extensive disruptions in converters, suggestive of severity-related demyelination or axonal pathology. Fine-grained but detectable differences among ultra-high-risk subjects (i.e., with brief limited intermittent and/or attenuated psychotic symptoms) point to the splenium as a discrete site of emerging psychopathology, while basic symptoms alone were not associated with altered fractional anisotropy.

Associations between inflammatory marker profiles and neurocognitive functioning in people with schizophrenia and non-psychiatric comparison subjects

BACKGROUND

Cognitive dysfunction in schizophrenia is the key predictor of functional disability and drives economic burden. Inflammation has been increasingly implicated in the pathogenesis of schizophrenia, yet its role in cognitive decline has not been evaluated. This study explores the association between inflammation and cognitive functioning in persons with schizophrenia.

METHODS

Participants included 143 persons with schizophrenia (PwS) and 139 non-psychiatric comparison subjects (NCs) from an ongoing study of aging. Cognitive assessments included validated measures for executive functioning, processing speed, and visuospatial skills. Plasma levels of nine biomarkers associated with inflammation (high sensitivity C-reactive protein, intercellular adhesion molecule 1, serum amyloid A, interleukin-6, interleukin-8, interferon gamma-induced protein-10, monocyte chemotactic protein-1, fractalkine, and brain-derived neurotrophic factor) were quantified using commercially available, enzyme-linked immunosorbent assays. Partial least squares regression was used to develop a composite "inflammatory profile" to maximize correlations with the cognitive outcomes. We then constructed a best-fit model using these composites and their interactions with diagnosis and sex as the predictors, controlling for covariates.

RESULTS

The biomarker composite, which best correlated with scores on cognitive testing, included high sensitivity C-reactive protein, intercellular adhesion molecule 1, serum amyloid A, interleukin-6, and brain-derived neurotrophic factor, for a 5-biomarker "inflammatory profile." The best-fit model showed a significant biomarker composite by diagnosis by sex three-way interaction, for executive function and processing speed, but not visuospatial skill.

CONCLUSIONS

This approach to building an "inflammatory profile" may provide insight into inflammatory pathways affecting brain function and potential targets for anti-inflammatory interventions to improve cognition in schizophrenia.

Peripheral complement is increased in schizophrenia and inversely related to cortical thickness

BACKGROUND

There is growing evidence for complement system involvement in the pathophysiology of schizophrenia, although the extent and magnitude of complement factor disturbances has not been fully reported. It also remains unclear whether complement abnormalities are characteristic of all patients with schizophrenia or whether they are representative of a subgroup of patients who show signs of heightened inflammation. The aim of the present study was to quantify and compare the levels of a range of complement factors, receptors and regulators in healthy controls and people with schizophrenia and to determine the extent to which the levels of these peripheral molecules relate to measures of brain structure, particularly cortical thickness.

METHOD

Seventy-five healthy controls and 90 patients with schizophrenia or schizoaffective disorder were included in the study. Peripheral blood samples were collected from all participants and mRNA expression was quantified in 20 complement related genes, four complement proteins, as well as for four cytokines. T1-weighted structural MRI scans were acquired and analysed to determine cortical thickness measures.

RESULTS

There were significant increases in peripheral mRNA encoding receptors (C5ar1, CR1, CR3a), regulators (CD55, C59) and protein concentrations (C3, C3b, C4) in people with schizophrenia relative to healthy controls. C4a expression was significantly increased in a subgroup of patients displaying elevated peripheral cytokine levels. A higher inflammation index score derived from mRNA expression patterns predicted reductions in cortical thickness in the temporal lobe (superior temporal gyrus, transverse temporal gyrus, fusiform gyrus, insula) in patients with schizophrenia and healthy controls.

CONCLUSIONS

Analysis of all three major complement pathways supports increased complement activity in schizophrenia and also shows that peripheral C4a up-regulation is related to increased peripheral pro-inflammatory cytokines in healthy controls. Our region-specific, neuroimaging findings linked to an increased peripheral complement mRNA expression pattern suggests a role for complement in cortical thinning. Further studies are required to further clarify clinical and neurobiological consequences of aberrant complement levels in schizophrenia and related psychoses.

Black Seed (Nigella sativa) Efficacy in Improving Clinical Symptoms and Interleukin-6 Levels Schizophrenic Patients

BACKGROUND: Schizophrenia with a global prevalence of 0.33–0.75% and one of the top 15 causes of disability. The etiology underlying this disease is still controversial. One of the causes is the Vulnerability Stress-Schizophrenia Inflammatory Model which shows an increase in pro-inflammatory cytokines, one of which is Interleukin-6 (IL-6). AIM: It is hoped that through the adjuvant anti-inflammatory effect of black seed or Nigella sativa can improve the clinical symptoms of schizophrenia and reduce levels of Serum IL-6 as a marker of therapeutic efficacy, as well as observing the effect of treatment on liver function. METHODS: The present study was conducted 22 schizophrenic patients hospitalized at the psychiatric hospital (Rumah Sakit Khusus Daerah) of South Sulawesi aged 20–45 years and received risperidone 4 mg/day therapy. Patients were divided into two groups, the control and treatment groups received N. sativa 1000 mg/d for 4 weeks. Each group was measured for baseline and week 4 clinical symptoms of schizophrenia with Positive and Negative Symptom of Schizophrenia (PANSS) and serum IL-6 levels. The analysis also measured serum IL-6 levels in 14 healthy people by assessing the side effects of N. sativa adjuvants by measuring liver function enzymes of Serum Glutamic Oxaloacetic Transaminase (SGOT) and Serum Glutamic Pyruvic Transaminase (SGPT). RESULTS: Serum IL-6 levels of schizophrenic patients were higher than healthy controls. Administration of adjuvant N. sativa 1000 mg for 4 weeks significantly p < 0.001 improved PANSS value, decreased serum IL-6 levels 2.5 times faster in the treatment group and did not give a significant change in SGOT and SGPT values. CONCLUSION: This study suggests that N. sativa may consider as an adjuvant therapy to improve clinical symptoms of schizophrenia and reduce levels of IL-6 was faster than control group and is safe for liver function.

Neutrophil/lymphocyte, platelet/lymphocyte and monocyte/lymphocyte ratios in schizophrenia

OBJECTIVE

Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) have been used as markers of inflammation in mental illness. However, these indices have not been widely used in schizophrenia research in Chinese participants. Our aim was to use these ratios to explore the relationship between schizophrenia and inflammation.

METHODS

In this retrospective cross-sectional study, we collected total blood cell counts of 549 patients with schizophrenia and 930 healthy controls at Beijing Huilongguan Hospital in October 2019. We analyzed the subjects' platelet, lymphocyte, monocyte, and neutrophil counts; compared the calculated NLR, MLR, and PLR between patients and healthy controls; and evaluated the correlations with age and gender.

RESULTS

Platelet and lymphocyte counts were significantly lower, while NLR and MLR were significantly higher, in patients with schizophrenia compared to healthy controls. Additionally, monocyte count, lymphocyte count, MLR, and NLR were different between male and female subjects.

CONCLUSION

This study supports the inflammatory hypothesis of schizophrenia in the Chinese population.

Effect of dimethyl fumarate on the changes in the medial prefrontal cortex structure and behavior in the poly(I:C)-induced maternal immune activation model of schizophrenia in the male mice

BACKGROUND

The link between maternal immune activation (MIA) and the risk of developing schizophrenia (SCZ) later in life has been of major focus in recent years. This link could be bridged by activated inflammatory pathways and excessive cytokine release resulting in adverse effects on behavior, histology, and cytoarchitecture. The down-regulatory effects of immunomodulatory agents on the activated glial cells and their therapeutic effects on schizophrenic patients are consistent with this hypothesis.

OBJECTIVE

We investigated whether treatment with the anti-inflammatory drug dimethyl fumarate (DMF) could rescue impacts of prenatal exposure to polyinosinic:polycytidylic acid [poly (I:C)].

METHODS

Pregnant dams were administered poly(I:C) at gestational day 9.5. Offspring born from these mothers were treated with DMF for fourteen consecutive days from postnatal day 80 and were assessed behaviorally before and after treatment. The brains were then stained with Cresyl Violet or Golgi-Cox. In addition to the estimation of stereological parameters, cytoarchitectural changes were also evaluated in the medial prefrontal cortex.

RESULTS

MIA caused some abnormalities in behavior, as well as changes in the number of neurons and non-neurons. These alterations were also extended to pyramidal layer III neurons with a significant decrease in dendritic complexity and spine density which DMF treatment could prevent these changes. Furthermore, DMF treatment was also effective against abnormal exploratory and depression-related behavior, but not the changes in the number of cells.

CONCLUSION

These findings support the idea of using anti-inflammatory agents as adjunctive therapy in patients with SCZ.

Mechanisms underlying dorsolateral prefrontal cortex contributions to cognitive dysfunction in schizophrenia

Kraepelin, in his early descriptions of schizophrenia (SZ), characterized the illness as having "an orchestra without a conductor." Kraepelin further speculated that this "conductor" was situated in the frontal lobes. Findings from multiple studies over the following decades have clearly implicated pathology of the dorsolateral prefrontal cortex (DLPFC) as playing a central role in the pathophysiology of SZ, particularly with regard to key cognitive features such as deficits in working memory and cognitive control. Following an overview of the cognitive mechanisms associated with DLPFC function and how they are altered in SZ, we review evidence from an array of neuroscientific approaches addressing how these cognitive impairments may reflect the underlying pathophysiology of the illness. Specifically, we present evidence suggesting that alterations of the DLPFC in SZ are evident across a range of spatial and temporal resolutions: from its cellular and molecular architecture, to its gross structural and functional integrity, and from millisecond to longer timescales. We then present an integrative model based upon how microscale changes in neuronal signaling in the DLPFC can influence synchronized patterns of neural activity to produce macrocircuit-level alterations in DLPFC activation that ultimately influence cognition and behavior. We conclude with a discussion of initial efforts aimed at targeting DLPFC function in SZ, the clinical implications of those efforts, and potential avenues for future development.

European Psychiatric Association guidance on treatment of cognitive impairment in schizophrenia

Background

Although cognitive impairment is a core symptom of schizophrenia related to poorer outcomes in different functional domains, it still remains a major therapeutic challenge. To date, no comprehensive treatment guidelines for cognitive impairment in schizophrenia are implemented.

Methods

The aim of the present guidance paper is to provide a comprehensive meta-review of the current available evidence-based treatments for cognitive impairment in schizophrenia. The guidance is structured into three sections: pharmacological treatment, psychosocial interventions, and somatic treatments.

Results

Based on the reviewed evidence, this European Psychiatric Association guidance recommends an appropriate pharmacological management as a fundamental starting point in the treatment of cognitive impairment in schizophrenia. In particular, second-generation antipsychotics are recommended for their favorable cognitive profile compared to first-generation antipsychotics, although no clear superiority of a single second-generation antipsychotic has currently been found. Anticholinergic and benzodiazepine burdens should be kept to a minimum, considering the negative impact on cognitive functioning. Among psychosocial interventions, cognitive remediation and physical exercise are recommended for the treatment of cognitive impairment in schizophrenia. Noninvasive brain stimulation techniques could be taken into account as add-on therapy.

Conclusions

Overall, there is definitive progress in the field, but further research is needed to develop specific treatments for cognitive impairment in schizophrenia. The dissemination of this guidance paper may promote the development of shared guidelines concerning the treatment of cognitive functions in schizophrenia, with the purpose to improve the quality of care and to achieve recovery in this population.

Progress and Pitfalls in Developing Agents to Treat Neurocognitive Deficits Associated with Schizophrenia

Cognitive impairments associated with schizophrenia (CIAS) represent a central element of the symptomatology of this severe mental disorder. CIAS substantially determine the disease prognosis and hardly, if at all, respond to treatment with currently available antipsychotics. Remarkably, all drugs presently approved for the treatment of schizophrenia are, to varying degrees, dopamine D₂/D₃ receptor blockers. In turn, rapidly growing evidence suggests the immense significance of systems other than the dopaminergic system in the genesis of CIAS. Accordingly, current efforts addressing the unmet needs of patients with schizophrenia are primarily based on interventions in other non-dopaminergic systems. In this review article, we provide a brief overview of the available evidence on the importance of specific systems in the development of CIAS. In addition, we describe the promising targets for the development of new drugs that have been used so far. In doing so, we present the most important candidates that have been investigated in the field of the specific systems in recent years and present a summary of the results available at the time of drafting this review (May 2022), as well as the currently ongoing studies.

IL-17 and TNF-β: Predictive biomarkers for transition to psychosis in ultra-high risk individuals

BACKGROUND

Dysregulation of immunity, such as levels of inflammatory factors, has been regarded as a sign of schizophrenia. Changes in cytokine levels are not only described in the early onset of disease, but also observed in ultra-high risk (UHR) individuals. This study aimed to investigate the potential of cytokines as biomarkers for psychotic disorders and in individuals at UHR of developing a psychotic disorder in the future.

METHODS

The Luminex liquid chip technology was used to detect the concentrations of Interferon-gamma (INF-γ), Interleukin (IL)-2, Interleukin (IL)-4, Interleukin (IL)-6, Interleukin (IL)-17, Interleukin-1beta (IL-1β), and Tumor Necrosis Factor-beta (TNF-β) in the plasma of all subjects. Meanwhile, the plasma level of Tumor Necrosis Factor-Alpha (TNF-α) was measured with the enzyme-linked immunosorbent assay (ELISA) kits. Then, the levels of these cytokines were compared among patients with Drug-naïve first-episode schizophrenia (FES; n = 40), UHR population (UHR; n = 49), and healthy controls (HCs; n = 30). Baseline cytokine levels were compared among UHR individuals who later transitioned (UHR-T; n = 14), those who did not transition (UHR-NT; n = 35), and HCs (n = 30).

RESULTS

Our analysis results showed that IL-1β levels were significantly higher in UHR group than HC group (p = 0.015). Meanwhile, TNF-α concentration was significantly increased in FES group compared with HC group (p = 0.027). IL-17 (p = 0.04) and TNF-β (p = 0.008) levels were significantly higher in UHR-T group compared with UHR-NT group.

CONCLUSION

In conclusion, our findings suggest that the immuno-inflammatory activation level is increased in the early stage of psychosis before psychotic conversion and the Drug-naïve FES. IL-1β and TNF-α are the representatives of the specific biomarkers for UHR and FES, respectively. IL-17 and TNF-β may be the potential selective predictive biomarkers for future transition in UHR individuals.

[Oxidative stress in schizophrenia as a promising target for psychopharmacotherapy]

Until now, only dopamine receptor blockers are used for psychopharmacotherapy of schizophrenia, despite the active search for alternative pharmacological agents and a lot of research. However, most of these studies concerned molecules that somehow affect various neurotransmitter receptors. In addition, various anti-inflammatory drugs have been studied quite actively. At the same time, attempts to correct oxidative stress are given significantly less attention, although the emergence of the latter is facilitated by completely different pathophysiological processes and environmental factors associated with the development of schizophrenia. NMDA receptor blockage, vitamin D deficiency, social isolation, chronic stress in adolescence, inflammation, perinatal infection etc. - all this can ultimately lead to the occurrence of oxidative stress. However, there is a significant difference in the severity of this process depending on the stage of the course of schizophrenia, which probably partially explains the heterogeneity of results of the studies on the oxidative stress biomarkers in this disorder. In order to overcome these methodological problems, it seems promising to conduct double-blind studies of the effectiveness of antioxidants in schizophrenia with the selection of groups of patients taking into account the stage of the disorder and the level of certain biomarkers of oxidative stress (F2-isoprostanes, 8-oxodG, 8-oxoGuo). The optimal pharmacological agents for such studies are N-acetylcysteine due to the positive results of previous studies, and melatonin as an antioxidant with a unique activity profile.

Neuroinflammation in schizophrenia: the role of nuclear factor kappa B

Neuroinflammation, particularly in the dorsolateral prefrontal cortex, is well-established in a subset of people with schizophrenia, with significant increases in inflammatory markers including several cytokines. Yet the cause(s) of cortical inflammation in schizophrenia remains unknown. Clues as to potential microenvironmental triggers and/or intracellular deficits in immunoregulation may be gleaned from looking further upstream of effector immune molecules to transcription factors that control inflammatory gene expression. Here, we focus on the 'master immune regulator' nuclear factor kappa B (NF-κB) and review evidence in support of NF-κB dysregulation causing or contributing to neuroinflammation in patients. We discuss the utility of 'immune biotyping' as a tool to analyse immune-related transcripts and proteins in patient tissue, and the insights into cortical NF-κB in schizophrenia revealed by immune biotyping compared to studies treating patients as a single, homogenous group. Though the ubiquitous nature of NF-κB presents several hurdles for drug development, targeting this key immunoregulator with novel or repurposed therapeutics in schizophrenia is a relatively underexplored area that could aid in reducing symptoms of patients with active neuroinflammation.

Novel approaches in schizophrenia-from risk factors and hypotheses to novel drug targets

Schizophrenia is a severe psychiatric disorder characterized by emotional, behavioral and cognitive disturbances, and the treatment of schizophrenia is often complicated by noncompliance and pharmacoresistance. The search for the pathophysiological mechanisms underlying schizophrenia has resulted in the proposal of several hypotheses to explain the impacts of environmental, genetic, neurodevelopmental, immune and inflammatory factors on disease onset and progression. This review discusses the newest insights into the pathophysiology of and risk factors for schizophrenia and notes novel approaches in antipsychotic treatment and potential diagnostic and theranostic biomarkers. The current hypotheses focusing on neuromediators (dopamine, glutamate, and serotonin), neuroinflammation, the cannabinoid hypothesis, the gut-brain axis model, and oxidative stress are summarized. Key genetic features, including small nucleotide polymorphisms, copy number variations, microdeletions, mutations and epigenetic changes, are highlighted. Current pharmacotherapy of schizophrenia relies mostly on dopaminergic and serotonergic antagonists/partial agonists, but new findings in the pathophysiology of schizophrenia have allowed the expansion of novel approaches in pharmacotherapy and the establishment of more reliable biomarkers. Substances with promising results in preclinical and clinical studies include lumateperone, pimavanserin, xanomeline, roluperidone, agonists of trace amine-associated receptor 1, inhibitors of glycine transporters, AMPA allosteric modulators, mGLUR_2-3 agonists, D-amino acid oxidase inhibitors and cannabidiol. The use of anti-inflammatory agents as an add-on therapy is mentioned.

Does the Interaction between Local and Systemic Inflammation Provide a Link from Psychology and Lifestyle to Tissue Health in Musculoskeletal Conditions?

Musculoskeletal conditions are known to involve biological, psychological, social and, often, lifestyle elements. However, these domains are generally considered in isolation from each other. This siloed approach is unlikely to be adequate to understand the complexity of these conditions and likely explains a major component of the disappointing effects of treatment. This paper presents a hypothesis that aims to provide a foundation to understand the interaction and integration between these domains. We propose a hypothesis that provides a plausible link between psychology and lifestyle factors with tissue level effects (such as connective tissue dysregulation/accumulation) in musculoskeletal conditions that is founded on understanding the molecular basis for interaction between systemic and local inflammation. The hypothesis provides plausible and testable links between mind and body, for which empirical evidence can be found for many aspects. We present this hypothesis from the perspective of connective tissue biology and pathology (fibrosis), the role of inflammation locally (tissue level), and how this inflammation is shaped by systemic inflammation through bidirectional pathways, and various psychological and lifestyle factors via their influence on systemic inflammation. This hypothesis provides a foundation for new consideration of the development and refinement of personalized multidimensional treatments for individuals with musculoskeletal conditions.

Dysregulated inflammation may predispose patients with serious mental illnesses to severe COVID‑19 (Review)

Genetic and nongenetic factors associated with an increased inflammatory response may mediate a link between severe coronavirus disease 2019 (COVID‑19) and serious mental illness (SMI). However, systematic assessment of inflammatory response‑related factors associated with SMI that could influence COVID‑19 outcomes is lacking. In the present review, dietary patterns, smoking and the use of psychotropic medications are discussed as potential extrinsic risk factors and angiotensin‑converting enzyme (ACE) insertion/deletion (I/D) gene polymorphisms are considered as potential intrinsic risk factors. A genetics‑based prediction model for SMI using ACE‑I/D genotyping is also proposed for use in patients experiencing severe COVID‑19. Furthermore, the literature suggests that ACE inhibitors may have protective effects against SMI or severe COVID‑19, which is often linked to hypertension and other cardiovascular comorbidities. For this reason, we hypothesize that using these medications to treat patients with severe COVID‑19 might yield improved outcomes, including in the context of SMI associated with COVID‑19.