Background: The 22q11.2 deletion syndrome (22q11.2DS) is a microdeletion syndrome with highly variable phenotypic manifestations, even though most patients present the typical 3 Mb microdeletion, usually affecting the same ~ 106 genes.
View Article and Find Full Text PDFSchizophrenia (SCZ) is a severe psychiatric disorder with unclear pathophysiology. Moreover, there is no specific biological marker to help clinicians to define a diagnosis, and medication is decided according to the psychiatrist's experience. In this scenario, microRNAs (miRNAs), which are small noncoding RNA molecules that regulate several genes, emerge as potential peripheral biomarkers to help not only the evaluation of the disease state but also the treatment response.
View Article and Find Full Text PDFTraumatic brain injury (TBI) is a prevalent and debilitating condition, which often leads to the development of post-traumatic epilepsy (PTE), a condition that yet lacks preventive strategies. Biperiden, an anticholinergic drug, is a promising candidate that has shown efficacy in murine models of PTE. MicroRNAs (miRNAs), small regulatory RNAs, can help in understanding the biological basis of PTE and act as TBI- and PTE-relevant biomarkers that can be detected peripherally, as they are present in extracellular vesicles (EVs) that cross the blood-brain barrier.
View Article and Find Full Text PDFBraz J Psychiatry
November 2024
Objective: Post-traumatic stress disorder (PTSD) is triggered by traumatic events, but genetic vulnerability and a history of childhood trauma may also increase the risk of PTSD onset. Thus, we investigated the interaction between genetic susceptibility according to polygenic risk score (PRS), and traumatic events.
Methods: We evaluated 68 women with PTSD who had been sexually assaulted and 63 healthy controls with no history of sexual assault.
Introduction: Long interspersed nuclear elements (LINEs) are endogenous retrotransposable elements. A few studies have linked the methylation pattern of LINE-1 to different mental disorders (e.g.
View Article and Find Full Text PDFTelomeres are short tandem repeats of "TTAGGG" that protect the chromosome ends from deterioration or fusion of chromosomes. Their repeat length shortens with cell division acting as a biomarker of cellular aging. Traumatic stress events during adulthood or childhood have been associated with posttraumatic stress disorder (PTSD) and short leukocyte telomere length (LTL).
View Article and Find Full Text PDFTreatment-resistant schizophrenia (TRS) occurs in one-third of the patients, but the molecular determinants of poor antipsychotic response remain unclear. We compared genetic data of patients with TRS (n = 63) with non-TRS (n = 111) by polygenic risk scores (PRS) calculated by PRSice software using PGC2_SCZ (Psychiatric Genomics Consortium - Schizophrenia) data. TRS criteria followed the International Psychopharmacology Algorithm Project SCZ algorithm.
View Article and Find Full Text PDFA growing body of research demonstrates the association between neighborhood context and health. The underlying biological mechanisms of this association are not fully understood. We conducted a systematic review of studies that investigated the association between neighborhood context and telomere length (TL), a DNA-protein complex that shortens after cell division.
View Article and Find Full Text PDFPsychotic experiences (PE) are forms of hallucinations and delusions neither reaching the intensity and functional impairment required to be regarded as full psychotic symptoms nor a psychotic disorder. Here we investigated the ability to predict PE using multiple models (regressions, mediation and moderation) using polygenic risk score for psychotic experiences (PE-PRS), polygenic risk score for schizophrenia (SCZ-PRS), and polyenvironmental risk score (PERS) in youth from a Brazilian sample. The scores were not able to predict outcome, either when both scores were combined (PERS + PE-PRS and PERS + SCZ-PRS) or separately.
View Article and Find Full Text PDFSchizophrenia is a severe and multifactorial disorder with an unknown causative pathophysiology. Abnormalities in neurodevelopmental and aging processes have been reported. Relative telomere length (RTL) and DNA methylation age (DMA), well-known biomarkers for estimating biological age, are both commonly altered in patients with schizophrenia compared to healthy controls.
View Article and Find Full Text PDFBrain-derived neurotrophic factor (BDNF) and the immune-inflammatory response system (IRS) have been implicated in the pathophysiology of schizophrenia. However, no research examined the associations between BDNF and immune activation both before and after treatment in antipsychotic-naïve first episode psychosis (AN-FEP). This study aims to examine serum BDNF levels and their association with IRS and the compensatory immune-regulatory reflex system (CIRS) in AN-FEP before and after risperidone treatment.
View Article and Find Full Text PDFThalamic volume measures have been linked to obsessive-compulsive disorder (OCD) in children and adolescents. However, it is unclear if alterations in thalamic volumes occur before or after symptom onset and if there is a relation to the presence of sub-clinical obsessive-compulsive symptoms (OCS). Here, we explore the relationship between OCS and the rate of thalamic volume change in a cohort of children and youth at high risk to develop a mental disorder.
View Article and Find Full Text PDFThe development of alcohol use disorder (AUD) is influenced by genetic, psychological, and social factors. However, the identification of the load of each of these factors and the association between them is still debatable. This study aimed to explore the load of the association between AUD and polymorphisms in genes of the dopaminergic system, as well as with drinking triggers.
View Article and Find Full Text PDFBackground: Resistance to antipsychotic treatment affects up to 30% of patients with schizophrenia. Although the time course of development of treatment-resistant schizophrenia (TRS) varies from patient to patient, the reasons for these variations remain unknown. Growing evidence suggests brain dysconnectivity as a significant feature of schizophrenia.
View Article and Find Full Text PDFBackground: Our previous studies showed increased angiotensin I-converting enzyme (ACE) activity in chronic schizophrenia (SCZ) patients compared to healthy control (HC) volunteers, and the relevance of combining ACE genotype and activity for predicting SCZ was suggested.
Methods: ACE activity was measured in plasma of ACE insertion/deletion (I/D) genotyped HC volunteers (N = 53) and antipsychotic-naïve first-episode psychosis (FEP) patients (N = 45), assessed at baseline (FEB-B) and also after 2-months (FEP-2M) of treatment with the atypical antipsychotic risperidone.
Results: ACE activity measurements showed significant differences among HC, FEP-B and FEP-2M groups (F = 5.
We investigated the DNA methylation profile over LINE-1 in antipsychotic-naive, first-episode psychosis-patients (n = 69) before and after 2 months of risperidone treatment and in healthy controls (n = 62). Patients were evaluated using standardized scales and classified as responders and nonresponders. DNA from blood was bisulfite converted and LINE-1 fragments were amplified and pyrosequencing was performed.
View Article and Find Full Text PDFDiscrimination is unfair treatment against a certain group based on race, age, gender, sexual orientation, or other social identities. Discrimination is pervasive in society, elevates psychosocial stress, and is associated with negative mental and physical health outcomes. However, more research is needed to understand the biological mechanisms underlying discrimination-related health disparities.
View Article and Find Full Text PDFWe aimed to identify blood gene expression patterns associated to psychopathological trajectories retrieved from a large community, focusing on the emergence and remission of general psychiatric symptoms. Hundred and three individuals from the Brazilian High-Risk Cohort Study (BHRCS) for mental disorders were classified in four groups according to Child Behavior Checklist (CBCL) total score at the baseline (w0) and after 3 years (w1): low-high (L-H) (N = 27), high-low (H-L) (N = 12), high-high (H-H) (N = 34) and low-low (L-L) groups (N = 30). Blood gene expression profile was measured using Illumina HT-12 Beadchips, and paired analyses comparing w0 and w1 were performed for each group.
View Article and Find Full Text PDFObjective: Mental disorders can have a major impact on brain development. Peripheral blood concentrations of brain-derived neurotrophic factor (BDNF) are lower in adult psychiatric disorders. Serum BDNF concentrations and BDNF genotype have been associated with cortical maturation in children and adolescents.
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