Effects of IL-6/IL-6R axis alterations in serum, plasma and cerebrospinal fluid with the schizophrenia: an updated review and meta-analysis of 58 studies.

Studies investigating the association between IL-6/IL-6R axis and schizophrenia (SZ) susceptibility found inconsistent data. To reconcile the results, a systematic review followed by a meta-analysis was performed to assess the associations. This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A comprehensive search of the literature was carried out in July 2022 using electronic databases PubMed, EBSCO, Science Direct, PsychInfo, and Scopus. Study quality was assessed by the Newcastle-Ottawa scale. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effect or random-effect model analysis. Fifty-eight studies were identified, including 4,200 SZ patients and 4,531 controls. Our meta-analysis results showed an increase of IL-6 levels in plasma, serum, or CSF and decreased IL-6R levels in serum in patients under treatment. Further studies are needed to better elucidate the correlation between the IL-6/IL-6R axis and the schizophrenia.

The role of SKA2 on affective disorder, post-traumatic stress disorder and suicide behavior: systematic review and in silico analysis.

Genes involved in the hypothalamic-pituitary-adrenal axis may be a robust biomarker of psychiatric disorders. Genetic polymorphisms of the SKA2 gene are associated with several behavioral disorders. In this study, we embarked on a systematic search of all possible reports of genetic association with SKA2 and affective disorder, post-traumatic stress disorder, and suicide behavior; the functional consequences of nsSNPs were explored through computational tools with an in silico analysis. Eight eligible articles were included. Our study identified that SKA2 did not show association with risk of Major Depression Disorder. Epigenetic variation at SKA2 mediates vulnerability to Post-Traumatic Stress Disorder. Studies provide strong preliminary evidence that alterations at the SKA2 gene covary with types of suicide behavior, including suicidal ideation, attempts, and completions. Results from in silico analysis predicted that I22S, I22G, I78T, A15L, D18R, R25L, N42I, Y21S, K14I, K14L, and L60R were the most structurally and functionally significant nsSNPs in SKA2. Amino acid conservation analysis revealed that the amino acids were highly conserved and some dissimilarities of mutant type amino acids from wild-type amino acids such as charge, size, and hydrophobicity were observed. In the future, SKA2 gene have the potential to be evaluated as prognostic biomarkers for diagnosis and research.

Association between the HTR1A rs6295 gene polymorphism and suicidal behavior: an updated meta-analysis.

Several association studies have indicated that the HTR1A gene is associated with suicidal behavior (SB). Thus, a systematic assessment of the association of HTR1A was performed based on a literature review and pooled analysis. Four electronic databases were comprehensively searched to find and pinpoint all case-control articles related to this study. When analyzing the genetic association with SB, data were divided into: (A) SB cases vs. healthy controls and (B) SB cases vs. psychiatric controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were assessed as measures of association. Heterogeneity among included studies was analyzed using sensitivity test and Q statistics. Publication bias was also explored by Egger and rank correlation test. Thirteen case-control studies were selected in this meta-analysis, involving 2817 SB patients, 2563 healthy controls and 545 psychiatric controls. In the overall comparison between SB cases and healthy controls, result showed that the rs6295 polymorphisms of HTR1A gene was associated with SB, but only when using the recessive model (OR = 2.21, 95% CI = 1.80-2.71, P < 0.001). In the smaller sample size comparison between SB and psychiatric controls, no significant association was detected with rs6295 in any of the five genetics models tested. The present meta-analysis suggests that rs6295 polymorphism of HTR1A gene could increase the risk for SB. Well-designed studies with more patients will be required to validate these results.

Oxytocin levels in individuals with schizophrenia are high in cerebrospinal fluid but low in serum: A systematic review and meta-analysis : Oxytocin and Schizophrenia.

Schizophrenia is a debilitating mental illness. Levels of oxytocin have been proposed as a biomarker of schizophrenia; however, the observed levels of oxytocin in individuals with schizophrenia have been inconsistent across studies. We performed a meta-analysis to evaluate oxytocin levels in plasma, serum and cerebrospinal fluid to see if there are statistically different concentrations between individuals with schizophrenia and the comparison group. The meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Following the inclusion and exclusion criteria, 14 studies were included in the meta-analysis. The quality of the study was evaluated by the Newcastle-Ottawa Scale (NOS). A random-effects model was performed using the Comprehensive Meta-analysis software with the standardized mean difference (SMD) and 95% confidence intervals (CIs). Serum oxytocin levels in individuals with schizophrenia were significantly lower than that in comparison group (SMD = - 1.74, 95% CI = - 3.22 to - 0.26, p = 0.02) but cerebrospinal fluid oxytocin levels in individuals with schizophrenia were significantly higher than those in the comparison group (SMD = 0.55, 95% CI = 0.05 to 1.04, p = 0.03). Our results suggest that oxytocin levels in cerebrospinal fluid are increased in individuals with schizophrenia but decreased in serum. Therefore, the oxytocin system dysregulation may play a role in the pathophysiology of schizophrenia and it should be measured in more populations for a possible implementation as a biomarker of schizophrenia.

Abdominal Surgical Site Infection Incidence and Risk Factors in a Mexican Population.

OBJECTIVE: To investigate possible predictors and prevalence of surgical site infections (SSIs) in a group of Mexican patients who underwent open abdominal surgery. METHODS: This retrospective study included all patients (N = 755) who underwent elective or emergency open abdominal surgeries from October 2011 to March 2012. MAIN OUTCOME MEASURE: Sociodemographic and clinical characteristics were collected through preoperative and postoperative examinations by the infection surveillance team. The relationship among variables (age, gender, body mass index, comorbidities, smoking habit, antimicrobial prophylaxis, hair removal, American Society of Anesthesiologists classification, type of operation, duration of operation, and SSI classification) was analyzed by odds ratio and χ tests. MAIN RESULTS: Of the 755 patients, 91 (12%) suffered from SSI. Several variables were associated with SSI: American Society of Anesthesiologists classification (P = .001) and receiving preoperative prophylactic antimicrobials (P < .0001), among other factors. Isolated pathogens were mostly enterobacteria (60%). CONCLUSIONS: Surveillance plays an important role in the control and prevention of SSI. Providers must implement appropriate procedures to reduce SSI after abdominal surgery.

Astrogliosis and decreased neural viability as consequences of early consumption of aspartame and acesulfame potassium in male Wistar rats.

Artificial sweeteners are mainly used as substitutes for sucrose derivates. In this study, we analyzed if the chronic consumption of aspartame or acesulfame potassium at an early age, produces histological alterations, astrogliosis and decreased neuronal viability, in hippocampus, prefrontal cortex, amygdala and hypothalamus of male Wistar rats. A histological analysis was performed on male Wistar rats that consumed aspartame or acesulfame potassium during 90 days, initiating the consumption of sweeteners immediately after weaning. The evaluation of neuronal morphology in different areas of the brain was performed with hematoxylin - eosin staining. To measure astrogliosis and neuronal viability, we used the immunohistochemical technique, with the glial fibrillary acidic protein immunomodulators (GFAP) and with neuronal-specific enolase (NSE). The consumption of aspartame or acesulfame potassium promoted morphological changes of neurons including increased pyknotic nuclei and vacuolization in all the brain areas studied. In hippocampus, prefrontal cortex, amygdala and hypothalamus, astrogliosis and reduction of neural viability were observed in sweeteners consumers in comparison with the control group. Chronic consumption of ASP and ACK from early stages of development and during long periods, may promote neural modifications, astrogliosis and decrease neuronal viability in prefrontal cortex, amygdala, hippocampus, and hypothalamus.

Association between Polymorphisms of the DRD2 and ANKK1 Genes and Suicide Attempt: A Preliminary Case-Control Study in a Mexican Population.

BACKGROUND: The aim of this study was to analyze the possible association of polymorphic variants of the DRD2 and ANKK1 genes with suicide attempt in a Mexican population. METHODS: We conducted a case-control study in 289 subjects (166 suicide attempters and 123 healthy controls). We genotyped 2 polymorphisms of DRD2 (rs6275 and rs1799978) and 1 polymorphism of ANKK1 (rs1800497); then we analyzed the association between suicide attempt and these polymorphisms through genotypes, alleles, and inheritance models. RESULTS: Individuals who carried the TT genotype of the rs1800497 showed a 3-fold risk of attempting suicide (OR = 3.01; 95% CI 1.56-5.81, p = 0.001) when evaluated through the recessive model. In an analysis stratified by gender, this risk factor remained present among females (OR = 2.81; 95% CI 1.37-5.75) as well as males (OR = 3.3; 95% CI 1.01-10.77). CONCLUSION: Our results suggest that the rs1800497 variant of the ANKK1 gene could increase the risk of suicide attempt in a Mexican population. However, further studies using larger samples are necessary to obtain more conclusive results.

The role of C957T, TaqI and Ser311Cys polymorphisms of the DRD2 gene in schizophrenia: systematic review and meta-analysis.

BACKGROUND: The association between the dopamine D2 receptor (DRD2) gene and schizophrenia has been studied though no conclusive outcomes have been attained. The aim of this study was to perform a systematic review and meta-analysis to explore the relation between three polymorphisms of the DRD2 gene (C957T, TaqI and Ser311Cys) and schizophrenia. METHODS: The search was made in PubMed and EBSCO databases (up to February 2016). The systematic review included 34 case-control association studies (34 for C957T, 16 for TaqI and 36 for Ser311Cys). The association analysis comprised the allelic, additive, dominant, and recessive genetic models. The meta-analysis was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. RESULTS: The meta-analysis showed that TaqI (additive model: OR 0.57, 95% CI 0.30-1.14) and C957T (additive model: OR 0.75, 95% OR 0.58-0.97, recessive model: OR 0.79, 95% CI 0.64-0.98) exert a protective effect against developing schizophrenia. However, the sub-analysis for the C957T variant showed that this polymorphism exhibits a risk factor effect on Chinese individuals (allelic model: OR 1.33, 95% CI 1.04-1.70). CONCLUSION: Our meta-analysis suggests an association of the DRD2 gene and the risk for schizophrenia, given that TaqI and C957T polymorphisms presented a protective effect against schizophrenia, and in the sub-analyses the C957T variant increased the risk for this disorder in the Chinese population.

Effect on the expression of drd2 and drd3 after neonatal lesion in the lymphocytes, nucleus accumbens, hippocampus and prefrontal cortex: comparative analysis between juvenile and adult Wistar rats.

BACKGROUND: Neonatal lesion in the ventral hippocampus (NLVH) is a validated animal model to study schizophrenia from a neurodevelopmental perspective. This animal model is also used to investigate how neonatal lesions may alter the genetic expression of dopaminergic receptors. The present study compares mRNA expression levels of dopamine receptors (drd2 and drd3) in lymphocytes and brain of NLVH animals at two different age stages: young and adult. METHODS: The NLVH procedure was performed on 20 male Wistar rats at postnatal days 5-7. The mRNA expression levels of drd2 and drd3 genes in lymphocytes, nucleus accumbens, hippocampus and prefrontal cortex were measured and analyzed at postnatal days 45 and 90. The results were compared and contrasted with respective sham groups. RESULTS: In lymphocytes, only in NLVH-adult group we observed drd2 mRNA expression, while drd2 mRNA expression was not observed in the NLVH-juvenile rats; on the other hand, the drd3 mRNA expression did not show significant statistical differences. In hippocampus no differences were observed between drd2 mRNA or drd3 mRNA expression when comparing juvenile/adult shams with NLVH groups. In the prefrontal area, a decrease in drd2 mRNA expression levels were observed in the NLVH-adult group (F(1,3) = 52.83, p = 0,005) in comparison to the sham-adult group. Finally, in the nucleus accumbens, a strong decrease of drd3 mRNA expression was observed in the NLVH-adult group in comparison to the sham-adult group (F(1,3) = 123,2, p < 0.001). CONCLUSIONS: Our results show that differences in drd2 and drd3 mRNA levels in NLVH-adults are patent when compared to the sham-adult group or with the NLVH-juvenile group. These findings suggest that the expression levels may be regulated during adulthood, leading to behavioral and neurochemical changes related to schizophrenia. Therefore, more studies are necessary to determine the role of dopamine receptors as possible molecular markers for neurodevelopmental changes associated with schizophrenia.

The Trp719Arg polymorphism of the KIF6 gene and coronary heart disease risk: systematic review and meta-analysis.

BACKGROUND: Genetic factors play an important role in the pathogenesis of coronary heart disease (CHD). Kinesin-like protein 6 (KIF6) is a new candidate gene for CHD, since it has been identified as a potential risk factor. The aim of this study was to perform a systematic review and meta-analysis of previously published association studies between the Trp719Arg polymorphism of KIF6 and the development of CHD. METHODS: Studies and abstracts investigating the relationship between the Trp719Arg polymorphism of KIF6 and subsequent risk for development of CHD were reviewed. Electronic search from Pubmed and EBSCO databases was performed between 1993 and 2014 to identify studies that fulfilled the inclusion criteria. To analyze the association we used the models: allelic, additive, dominant and recessive. Moreover, we conducted a sub-analysis by populations using the same four models. RESULTS: Twenty-three studies were included in the meta-analysis. The Trp719Arg polymorphism showed a significant association with CHD when the analysis comprised the population with myocardial infarction (MI) and the additive genetic model was used. Moreover, this polymorphism showed a protective association with CHD when the analysis comprised the whole population using the recessive genetic model. CONCLUSIONS: Our findings indicate that the Trp719Arg polymorphism of the KIF6 gene is an important risk factor for developing MI and that allele 719Arg may have a protective association to present CHD in all populations. PROSPERO REGISTRATION: CRD42015024602.

The association of cytokines genes (IL-6 and IL-10) with the susceptibility to schizophrenia: A systematic review and meta-analysis.

Cytokines are among the important effectors and messenger molecules for restoring the homeostasis tissue after an inflammatory response. The association between IL-6 and IL-10 genes polymorphisms with the schizophrenia susceptibility have yielded controversial results. To reconcile the results, a systematic review followed by meta-analysis was performed to assess the association. We carried out literature searches of PubMed, Scopus, EBSCO, and Web of Sciences databases. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to assess the strength of the association. Subgroup analysis, heterogeneity analyses, and publication bias were also calculated in the meta-analysis. A total of 22 case-control studies, consisting of 4,993 schizophrenic patients and 5,195 healthy controls, were included in the meta-analysis. The meta-analysis suggests that the IL-6 rs1800795 polymorphism displays a protective role against schizophrenia, while the IL-10 rs1800896 and rs1800872 polymorphisms confer an increased risk of schizophrenia. Similar results were found in subgroup analysis by ethnicity. We did not find association between IL-10 rs1800871 polymorphism and schizophrenia susceptibility. Finally, this meta-analysis suggested that the dysregulation of cytokines could lead to the pathogenesis of the schizophrenia.

DNA Methylation of Genes Involved in the HPA Axis in Presence of Suicide Behavior: A Systematic Review.

DNA methylation in genes of the hypothalamic-pituitary-adrenal (HPA) axis has been associated with suicide behavior. Through a systematic review, we aimed to evaluate DNA methylation levels of the genes involved in the HPA pathway and their association with suicide behavior. A search of articles was performed using PubMed and Science Direct, EBSCO. The terms included were "DNA methylation", "suicide", "epigenetics", "HPA axis" and "suicide behavior". This systematic review was performed by the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. Six studies comprising 743 cases and 761 controls were included in this systematic review. The studies included individuals with suicide ideation, suicide attempts or completed suicide and childhood trauma, post-traumatic stress disorder (PTSD), or depression. One study reported hypermethylation in GR in childhood trauma, while two studies found hypermethylation of NR3C1 in childhood trauma and major depressive disorder (MDD). Only one study reported hypermethylation in BNDF in people with MDD. FKBP5 was found to be hypermethylated in people with MDD. Another study reported hypermethylation in CRHBP. SKA2 was reported to be hypermethylated in one study and another study found hypomethylated both in populations with PTSD. CRHR1 was found to be hypermethylated in people with MDD, and the last study found hypomethylation in CRH. Our result showed that patients with suicidal behavior showed a DNA methylation state of genes of the HPA axis in association with psychiatric comorbidity and with adverse events. Genes of the HPA axis could play a role in suicidal behavior associated with adverse events and pathologies. As a result, DNA methylation levels, proteins, and genes involved in the HPA axis could be considered for the search for biomarkers for the prevention of suicidal behavior in future studies.

Gene-environment interaction between HPA-axis genes and trauma exposure in the suicide behavior: A systematic review.

Suicide behavior (SB) emerge from complex interactions among traumatic events and multiple genetic factors. We conducted the first systematic review to assess the evidence of a link among trauma exposure, HPA-axis genes, and SB. A systematic search of PubMed, EBSCO, Science Direct, PsychInfo, and Scopus databases on gene-environment interaction, and susceptibility to SB was carried out until February 2022. Our study was prospectively registered in PROSPERO (CRD42022316141). A total of 13 epidemiological studies (11,756 subjects) were included: eight studies focused on traumatic experiences in the childhood and five studies on lifetime trauma exposure. All studies reported a positive association between the trauma exposure with SB. Gene-environment interaction was reported for CRHR1 (n = 6), CRHR2 (n = 2), FKBP5 (n = 2), and CRHBP (n = 1), however, for CRH, NR3C1, MC2R, and POMC genes no found gene-environment effects on SB. Trauma exposure could be one mechanism that links HPA-axis genes activity with the development of SB.

Mental Health Impact of the COVID-19 Pandemic on Mexican Population: A Systematic Review.

The COVID-19 pandemic has had an impact on mental health in the general population, but no systematic synthesis of evidence of this effect has been undertaken for the Mexican population. Relevant studies were identified through the systematic search in five databases until December, 2021. The selection of studies and the evaluation of their methodological quality were performed in pairs. The Newcastle-Ottawa Scale (NOS) was used for study quality appraisal. The protocol of this systematic review was registered with PROSPERO (protocol ID: CRD42021278868). This review included 15 studies, which ranged from 252 to 9361 participants, with a total of 26,799 participants. The findings show that COVID-19 has an impact on the Mexican population's mental health and is particularly associated with anxiety, depression, stress and distress. Females and younger age are risk factors for development mental health symptoms. Mitigating the negative effects of COVID-19 on mental health should be a public health priority in Mexico.

Association between TPH1 polymorphisms and the risk of suicide behavior: An updated meta-analysis of 18,398 individuals.

Objectives: We aimed to examine the association of TPH1 polymorphisms with the risk of suicide behavior (SB). Design: Systematic review and meta-analysis. Method: All relevant studies that evaluated the association between the A218C (rs1800532), A779C (rs1799913) and A6526G (rs4537731) polymorphisms and the susceptibility to SB published up to September 2021 were identified through a comprehensive systematic search in PubMed, Scopus, EBSCO and Science Direct electronic databases. The association between TPH1 gene polymorphisms and SB was evaluated using inherence models by odds ratio (OR) and 95% confidence interval (CI). Subgroup analyses, heterogeneity analyses, and publication bias were also tested in this meta-analysis. Results: The meta-analysis for TPH1 A218C revealed an increased risk of SB in the dominant model (OR = 1.11, 95%CI 1.01-1.22). We also observed a positive association in the allelic (OR = 1.13, 95%CI 1.05-1.21), homozygous (OR = 1.22, 95%CI 1.06-1.40), heterozygous (OR = 1.21, 95%CI 1.08-1.37) and dominant (OR = 1.21, 95%CI 1.09-1.34) inherence models with the suicide attempt. Additionally, in the heterozygous (OR = 0.84, 95%CI 0.73-0.97) and dominant (OR = 0.79, 95%CI 0.68-0.91) inherence models we detected an association with completed suicide. Based on ethnicity, an association of SB in the European population also was observed (OR = 1.29, 95%CI 1.12-1.51). However, for both A779C and A6526G polymorphisms we did not find evidence of an association with SB. Conclusion: This meta-analysis suggests that the A218C polymorphism of TPH1 gene could be a possible risk factor of SB. Future large-scale studies are required to analyze the molecular mechanisms by which affect the susceptibility of developing suicide behavior.

High Serum Levels of IL-6 Are Associated with Suicide Attempt but Not with High Lethality Suicide Attempts: A Preliminary Case-Control Study.

Suicide attempts are an emerging health problem around the world. Increased levels of IL-6 have been associated with suicidal behavior. Therefore, the aims of this study were to evaluate the serum levels of IL-6 in individuals with suicide attempts and a comparison group and to associate the IL-6 levels with the lethality of the suicide attempt. Additionally, we associated the rs2228145 polymorphism of the IL6R gene with suicide attempts or with the IL-6 serum levels. Suicide attempts and their lethality were evaluated using the Columbia Suicide Severity Rating Scale. The serum concentrations of IL-6 were measured by the ELISA technique in individuals with suicide attempts and then compared to a control group. The rs2228145 polymorphism of the IL6R gene was analyzed by real-time polymerase chain reaction. We found elevated serum levels of IL-6 in the suicide attempt group when compared to the control group (F = 10.37, p = 0.002). However, we found no differences of the IL-6 levels between high and low lethality. The IL6R gene polymorphism rs2479409 was not associated with suicide attempts. Our data suggest that IL-6 serum is increased in individuals with suicide attempts.

Association and Genetic Expression between Genes Involved in HPA Axis and Suicide Behavior: A Systematic Review.

BACKGROUND: Suicide behavior (SB) has been highly associated with the response to stress and the hypothalamic-pituitary-adrenal (HPA) axis. The aim of this study was to summarize the results obtained in genetic studies that analyzed the HPA axis-stress pathway and SB through a systematic review. METHODS: We performed an online search in PubMed, EBSCO, Web of Science, Scopus, and PsycoInfo databases up to May 2021. We followed the PRISMA guidelines for systematic reviews. We included case-control and expression studies that provided data on mRNA expression and single-nucleotide polymorphisms of genes associated with SB. RESULTS: A total of 21,926 individuals participated across 41 studies (not repeats); 34 studies provided data on single-nucleotide polymorphisms in 21,284 participants and 11 studies reported data on mRNA expression in 1034 participants. Ten genes were identified: FKBP5, CRH, CRHBP, CRHR1, CRHR2, NR3C1, NR3C2, SKA2, MC2R, and POMC. CONCLUSIONS: Our findings suggest that key stress pathway genes are significantly associated with SB and show potential as biomarkers for SB.

The role of rs242941, rs1876828, rs242939 and rs110402 polymorphisms of CRHR1 gene and the depression: systematic review and meta-analysis.

BACKGROUND: Several studies have evaluated the possible association between polymorphisms or variants in Corticotropin-releasing hormone 1 receptor gene (CRHR1) with depression; however, results remain contradictory and heterogeneous. OBJECTIVE: To our knowledge, we conducted the first comprehensive systematic review and meta-analysis evaluating the association of the CRHR1 gene and the risk of depression. METHODS: A search online was conducted in databases for any CRHR1 genetic association studies in depression. Data were extracted for evaluation of pooled estimates using meta-analytic techniques. Statistical analyses were performed using the Comprehensive Meta-analysis, v2.0 software. RESULT: A total of 1403 cases and 2353 mentally healthy controls were included in this study. We found a significant association of rs242941, rs1876828 and rs242939 variants of the CRHR1 gene with depression. No association of CRHR1 rs110402 and depression was observed. CONCLUSION: Our meta-analysis shows that some variants of the CRHR1 gene (rs242941, rs1876828 and rs242939) might confer susceptibility to depression. Further studies with larger sample sizes need to be conducted.

Knowledge, Emotions and Stressors in Front-Line Healthcare Workers during the COVID-19 Outbreak in Mexico.

The aim of this study was to explore the knowledge, emotions and perceived stressors by healthcare workers who were in contact with infected patients during the COVID-19 outbreak. An online cross-sectional survey was applied. Data were collected from N = 263 healthcare workers in Tabasco State, Mexico. We developed and administered a questionnaire, which consisted of sociodemographic characteristics, plus four sections. The sections evaluated were (1) knowledge of COVID-19; (2) feelings/emotions during the COVID-19 outbreak; (3) factors that caused stress and (4) factors that helped to reduce stress. Surveyed individuals were divided into three groups: physicians, nurses and other healthcare workers. When we evaluated their knowledge of COVID-19 we observed that the majority of healthcare workers in the three groups reported that they knew about COVID-19. Physicians indicated that they felt insecure about practicing their profession (62.5%) due to the high risk of being in contact with SARS-CoV-2. With regards to stressor factors, the risk of transmitting COVID-19 to their families was the main factor causing moderate to high stress (95.4%). Finally, we found that "your profession puts your life at risk" was the only factor associated with feeling nervous and scared (PR: 3.15; 95% CI: 1.54-6.43). We recommended health education campaigns, introductory courses on COVID-19 and other infectious diseases, management protocols and the provision of protection equipment to health workers in order to reduce personal and professional fears of contagion and to improve the health system in Mexico when facing epidemics.

Association between polymorphisms of FKBP5 gene and suicide attempt in a Mexican population: A case-control study.

Five polymorphisms (rs4713916, rs4713902, rs1360780, rs9296158 and rs3800373) of FKBP5 gene were analyzed in a case-control study comprising 423 Mexican individuals (146 individuals with suicide attempt and 277 controls). The SNP's were genotyped using the TaqMan-allelic assay. Genotype and allele frequencies were compared between the two groups, then the association between FKBP5 gene polymorphisms and suicide attempt was analyzed. We found a significant association of rs1360780 T minor allele (All, OR = 1.80, 95 % CI = 1.35-2.41, P = 0.0005; Males, OR = 2.25, 95 % CI = 1.44-3.50, P = 0.0002) as a suicide behavior risk factor. Conversely, rs3800373 C minor allele (All, OR = 0.61, 95 % CI = 0.46-0.83; P = 0.0013; Females, OR = 0.33, 95 % CI = 0.22-0.50; P = 0.0001) and the A-C-T-A-C haplotype (OR = 0.06, 95 % CI = 0.01-0.36; P = 0.002) were significantly associated as protective factors. No association was observed with the other SNP's. Our study suggests that SNP's in FKBP5 gene contribute to suicide behavior pathogenesis.