Joao Quevedo

• MD, PhD
• Professor (Full) at The University of Texas Health Science Center at Houston

It is known that an inflammatory response plays a key role in COVID-19 pathogenesis. An exacerbated inflammatory response can increase oxidative stress in cells. This study aimed to investigate the effects of COVID-19 on parameters of oxidative stress including non-protein thiol antioxidants (NPSH), protein thiols (PSH), total antioxidant capacity...

Given ketamine’s conflicting impacts on the central nervous system, investigating its effects within an inflammatory context becomes crucial. This study aimed to assess the impact of varying ketamine doses on neurotrophin and inflammatory cytokine levels within the brains of rats submitted to the sepsis model. Wistar rats were submitted to the ceca...

A practical handbook providing a succinct overview of the different aspects of mental health disorders, facilitating a solid base knowledge of the field of psychiatry. Offering a systematic, straightforward approach, the book covers the importance and relevance of mental health disorders, their causes, presentation, and the best approaches for thei...

Background The persistent neurological symptoms seen in long COVID survivors are attributed to immune system dysfunctions and changes in the microbiome induced by SARS‐CoV‐2 infection. In addition to the initial respiratory manifestations, a significant portion of COVID‐19 patients present with neurodegenerative symptoms. Our hypothesis suggests th...

The field of psychoneuroimmunology has significantly expanded in the last few decades and so has our understanding of the bidirectional communications between the immune and central nervous systems (CNS). There is a preponderance of evidence supporting the fact that immunological pathways and neuroinflammation are involved in the pathophysiology of...

Childhood maltreatment may be linked to epigenetics and brain-derived neurotrophic factor (BDNF) changes, which are mechanisms altered in several psychiatric conditions, including bipolar disorder (BD). However, the specific mechanisms connecting childhood maltreatment to the pathophysiology of BD remain unclear. The present study aims to examine t...

Bipolar Disorder (BD) is a chronic and highly debilitating psychiatric illness formerly called manic depression. Mood-stabilizing agents such as lithium (Li) are the primary drugs used to treat BD. Assessing the effect of these mood stabilizers is essential to develop a novel animal model of mania. Thus, the present work aimed to evaluate the ketam...

O suicídio é um grave problema de saúde pública com profundos impactos emocionais, sociais e econômicos. Este artigo aborda três estratégias essenciais para enfrentar essa questão: pós-venção, prevenção e promoção da saúde mental. Pós-venção envolve intervenções após um suicídio, oferecendo suporte às pessoas afetadas para mitigar traumas e preveni...

O suicídio é um grave problema de saúde pública com profundos impactos emocionais, sociais e econômicos. Este artigo aborda três estratégias essenciais para enfrentar essa questão: pós-venção, prevenção e promoção da saúde mental. Pós-venção envolve intervenções após um suicídio, oferecendo suporte às pessoas afetadas para mitigar traumas e preveni...

A complexidade dos comportamentos suicidas requer uma abordagem multifacetada para sua gestão, envolvendo a avaliação de fatores de risco e proteção, bem como intervenções apropriadas. A Associação Brasileira de Psiquiatria (ABP), por meio da sua Comissão de Emergências Psiquiátricas, elaborou diretrizes específicas para o manejo de pacientes com c...

Este artigo detalha as diretrizes para a triagem e avaliação do comportamento suicida. A triagem envolve o uso de instrumentos ou protocolos para identificar indivíduos com comportamentos suicidas, podendo ser aplicada de forma independente ou como parte de uma avaliação de saúde mais ampla. Esta pode ser realizada de maneira manual ou eletrônica e...

Neste artigo serão avaliados os fatores de risco e proteção para futuras tentativas e suicídio completo. Atualmente, não há meios precisos que garantam a predição do desfecho de uma fatalidade relacionada ao comportamento suicida. Sendo assim, a anamnese, o exame psíquico e a avaliação dos fatores mencionados são as ferramentas atuais que auxiliam...

O suicídio representa um grave desafio de saúde pública em escala mundial, resultando na perda anual de mais de 700 mil vidas, com uma incidência significativa entre a população jovem. No contexto brasileiro, a taxa de mortalidade por suicídio tem uma média de 5,23 por 100 mil habitantes. A despeito da existência de diversas diretrizes destinadas a...

Background Treatment of refractory bipolar disorder (BD) is extremely challenging. Deep brain stimulation (DBS) holds promise as an effective treatment intervention. However, we still understand very little about the mechanisms of DBS and its application on BD. Aim The present study aimed to investigate the behavioural and neurochemical effects of...

Major Depressive Disorder continues to remain one of the most prevalent psychiatric diseases globally. Despite multiple trials of conventional therapies, a subset of patients fail to have adequate benefit to treatment. Deep brain stimulation (DBS) is a promising treatment in this difficult to treat population and has shown strong antidepressant eff...

Aim: To investigate the factor structure, reliability, and validity of the Brazilian version of the Abbreviated Suicidal Narrative Inventory (SNI-38). Methods: We used an anonymous online questionnaire of the SNI-38 and self-report measures administered between November 2020 and October 2021 in the Brazilian community. Participants were recruite...

Objective: To examine the factor structure, reliability, and validity of the Brazilian version of the Suicide Crisis Inventory (SCI-2) among Brazilian adults. Methods: The SCI-2 was cross-culturally adapted into Portuguese and administered to 2,265 individuals in the Brazilian community. Confirmatory factor analyses, internal consistency, and co...

Suicide attempt (SA) risk is elevated in individuals with bipolar disorder (BD), and DNA methylation patterns may serve as possible biomarkers of SA. We conducted epigenome-wide association studies (EWAS) of blood DNA methylation associated with BD and SA. DNA methylation was measured at >700,000 positions in a discovery cohort of n = 84 adults wit...

Background Major depression has a complex and multifactorial etiology constituted by the interaction between genetic and environmental factors in its development. Objective The aim of this study was to evaluate the effects of sodium butyrate (SD) on epigenetic enzyme alterations in rats subjected to animal models of depression induced by maternal...

In this chapter, we explore the historical evolution, current applications, and future directions of Deep Brain Stimulation (DBS) for Treatment-Resistant Depression (TRD). We begin by highlighting the early efforts of neurologists and neurosurgeons who laid the foundations for today’s DBS techniques, moving from controversial lobotomies to the prec...

Although many efforts have been made to understand the pathophysiological mechanisms of COVID-19, critical gaps remain to be explored. This study aimed to investigate potential alterations in adipokine levels (specifically adiponectin, leptin, and resistin) among individuals with COVID-19. Within this population, we further assessed the association...

Background: Stressful life events are associated with higher odds of suicidal thoughts and behaviors. Furthermore, stressful life events can trigger specific symptoms, including the suicidal narrative and suicide crisis syndrome, resulting in an increased risk of suicidal thoughts and behaviors. This study examined the moderating role of suicide r...

This article aims to examine differences in suicidal narrative and suicide crisis syndrome symptoms, and suicidal ideation among those who maintained, lost, and gained employment or student status during the COVID-19 pandemic. It is a cross-sectional study based on an online and anonymous self-report questionnaire. Participants were recruited throu...

Although mitochondrial dysfunction is known to play an essential role in the pathophysiology of bipolar disorder (BD), there is a glaring gap in our understanding of how mitochondrial dysfunction can modulate clinical phenotypes. An emerging paradigm suggests mitochondria play an important non-energetic role in adaptation to stress, impacting cellu...

There is a growing body of evidence about the potential of diet and nutrients to improve the population's mental health and the treatment of psychiatric disorders. Some studies have suggested that resveratrol has therapeutic properties in mental disorders, such as major depressive disorder, bipolar disorder, Alzheimer's disease, and autism. In addi...

This study aimed to evaluate Haloperidol's (Hal) effects on the behavioral, neurotrophic factors, and epigenetic parameters in an animal model of schizophrenia (SCZ) induced by ketamine (Ket). Injections of Ket or saline were administered intraperitoneal (once a day) between the 1st and 14th days of the experiment. Water or Hal was administered via...

We are thrilled to announce the outstanding growth and recognition achieved by the Brazilian Journal of Psychia- try, as it achieves a remarkable 2023 JCR Impact Factor of 5.5. This significant milestone follows the all-time record of 2022, when the Impact Factor reached 6.0. It represents a steadfast commitment to excellence in psychiatric resea...

Background: Bipolar disorder (BD) is a chronic, severe, and multifactorial psychiatric disorder. Although biological rhythms alterations, sodium potassium pump (Na+,K+-ATPase) changes, and oxidative stress appear to play a critical role in the etiology and pathophysiology of BD, the inter-connection between them has not been described. Therefore t...

Suicide attempt (SA) risk is elevated in individuals with bipolar disorder (BD), and DNA methylation patterns may serve as possible biomarkers of SA. We conducted epigenome-wide association studies (EWAS) of blood DNA methylation associated with BD and SA. DNA methylation was measured at > 700,000 positions in a discovery cohort of n = 84 adults wi...

Background Treatment of refractory bipolar disorder (BD) is extremely challenging. Deep brain stimulation (DBS) holds promise as an effective treatment intervention. However, we still understand very little about the mechanisms of DBS and its application on BD. Aim The present study aimed to investigate the behavioural and neurochemical effects of...

Background and Aims: To evaluate the effect of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus on the function and metabolic changes, as well as the relationship of the virus with blood groups. Methods and Results: This cross-sectional study included a matched sample of adult individuals with coronavirus disease 2019 (COVID-1...

The present study aimed to evaluate if sepsis sensitizes behavioural and biochemical responses induced by m-amphetamine. For this, Wistar rats were submitted to the cecal ligation and puncture. After 30 days of cecal ligation and puncture procedure, the animals were submitted to a single intraperitoneal injection of saline or m-amphetamine (.25, .5...

Preclinical genetic studies have related stress early exposures with changes in gene regulatory mechanisms, including epigenetic alterations, such as modifications of DNA methylation, histone deacetylation, and histones acetylation. This study evaluates the effects of prenatal stress on the behavior, hypothalamus-pituitary-adrenal (HPA)-axis, and e...

Objective: Alterations in the kynurenine pathway are recognized in psychiatric disorders, but their role in Alzheimer's Disease (AD) is less clear. We aimed to conduct a systematic review and meta-analysis to verify if tryptophan and the metabolites of the kynurenine pathway are altered in AD. Methods: We performed a systematic review and random...

Introduction: The kynurenine pathway has been attracting attention as a relevant pathway in schizophrenia (SZ), bipolar disorder (BD), and major depressive disorder (MDD). We conducted a systematic review and meta-analysis of the kynurenine pathway metabolites from cerebrospinal fluid (CSF) samples in SZ, BD, and MDD. Methods: PubMed and Scopus...

Background: Bipolar disorder (BD) is a complex and severe mental disorder that affects 1-3 % of the world population. Studies have suggested the involvement of oxidative stress in the physiopathology of this psychiatry disorder. Folic acid (FA), a vitamin from the B complex, is a nutraceutical that has recently been researched as a possible treatm...

Immune dysfunction after SARS-CoV-2 infection leads to long COVID neurological sequels in COVID-19 survivors. Despite initial respiratory symptoms, neuropsychiatric manifestations have been reported in many COVID-19 patients. We aimed to investigate the psychological symptoms, gut microbiome status, and C-reactive protein levels (CRP) in post-COVID...

Bipolar disorder (BD) has been previously associated with premature mortality and aging, including acceleration of epigenetic aging. Suicide attempts (SA) are greatly elevated in BD and are associated with decreased lifespan, biological aging, and poorer clinical outcomes. We investigated the relationship between GrimAge, an epigenetic clock traine...

Background: Although many studies have pointed out a possible relationship between COVID-19 and the presence of psychiatric disorders, the majority of the studies have significant limitations. This study investigates the influence of COVID-19 infection on mental health. Methods: This cross-sectional study included an age- and sex-matched sample...

Major depressive disorder (MDD) etiology is still not completely understood, and many individuals resist the traditional treatments. Chronic exposure to stressful events can contribute to development and progression and be involved in biological changes underlying MDD. Among the biological mechanisms involved, inflammatory changes and oxidative bal...

Background: Crisis hotlines are described as a direct communication system, usually telephone, set up to prevent suicide. However, few studies have evaluated their effectiveness. Objective: The present study aims to perform a systematic review, using PRISMA, on the effectiveness of interventions through direct communication systems to reduce the...

Bipolar disorder (BD) has been previously associated with premature mortality and aging, including acceleration of epigenetic aging. Suicide attempts (SA) are greatly elevated in BD and are associated with decreased lifespan, biological aging, and poorer clinical outcomes. We investigated the relationship between GrimAge, an epigenetic clock traine...

Major depressive disorder (MDD) etiology is still not completely understood, and many individuals resist the traditional treatments. Chronic exposure to stressful events can contribute to development and progression and be involved in biological changes underlying MDD. Among the biological mechanisms involved, inflammatory changes and oxidative bal...

Major depressive disorder (MDD) etiology is still not completely understood, and many individuals resist the traditional treatments. Chronic exposure to stressful events can contribute to development and progression and be involved in biological changes underlying MDD. Among the biological mechanisms involved, inflammatory changes and oxidative bal...

IntroductionDespite possible risks of mania switching with the long-term use of antidepressants in patients with bipolar disorder (BD), these drugs may help in depressive episodes. Alterations in neurotrophic factor levels seem to be involved in the pathophysiology of BD. The present study aimed to evaluate the effect of acute treatment of imiprami...

Bipolar disorder (BD) has been previously associated with clinical signs of premature aging, including accelerated epigenetic aging in blood and brain, and a steeper age-related decline in cognitive function. However, the clinical drivers and cognitive correlates of epigenetic aging in BD are still unknown. We aimed to investigate the relationship...

Background: Studies have demonstrated an important impact of systemic inflammation in the central nervous system, which could be related to psychiatric disorders’ pathophysiology. Ketamine can have anti-inflammatory proprieties, but dose-dependently effects need to be studied. Objective: To evaluate the effect of different doses of ketamine on le...

Major depressive disorder (MDD) is the most prevalent mood disorder globally. Most antidepressants available for the treatment of MDD increase the concentration of monoamines in the synaptic cleft. However, such drugs have a high latency time to obtain benefits. Thus, new antidepressants with fast action and robust efficacy are very important. This...

Deep brain stimulation (DBS) to the superolateral branch of the medial forebrain bundle is an efficacious therapy for treatment-resistant depression, providing rapid antidepressant effects. In this study, we use 18F-fluorodeoxyglucose-positron emission tomography (PET) to identify brain metabolic changes over 12 months post-DBS implantation in ten...

Introduction A previous study from our Laboratory showed no alteration in inflammatory parameters seven days after ouabain (OUA) administration, a Na⁺K⁺ATPase inhibitor, which was previously considered only a mania model. However, the administration of OUA in rats was recently validated as a model of bipolar disorder (BD) symptoms, demonstrating th...

Introduction: Despite the risk of mania switch to long-term administration of antidepressants in bipolar disorder (BD) patients, an acute administration of these drugs can help in depressive episodes. Furthermore, alterations in neurotrophic factor levels seem to be part of the BD’s physiopathology. Therefore, the aim of the present study is to eva...

Deep brain stimulation (DBS) to the superolateral branch of the medial forebrain bundle (MFB) has emerged as a quite efficacious therapy for treatment resistant depression (TRD), leading to rapid antidepressant effects. In this study, we complete our assessment of our first 10 enrolled patients throughout one year post-implantation, showing sustain...

Schizophrenia and bipolar disorder, two of the most severe psychiatric illnesses, have historically been regarded as dichotomous entities but share many features of the premorbid course, clinical profile, genetic factors and treatment approaches. Studies focusing on neuroimaging findings have received considerable attention, as they plead for an im...

This study aimed at evaluating the treatment effects with ketamine, electroconvulsive stimulation (ECS), escitalopram, alone or in combination in adult rats of both sexes, subjected to the animal model of maternal deprivation (MD). All groups were subjected to the forced swimming test (FST), splash and open field tests. The prefrontal cortex (PFC),...

Bipolar disorder (BD) is a severe psychiatric disorder affecting approximately 1–3% of the population and characterized by a chronic and recurrent course of debilitating symptoms. An increasing focus has been directed to discover and explain the function of Blood-Brain Barrier (BBB) integrity and its association with a number of psychiatric disorde...

Tratamento do transtorno depressivo resistente aborda novas estratégias terapêuticas de tratamentos com mecanismos de ações diferentes dos monoaminergicos, bem como, terapias não farmacológicas disponíveis: Eletroconvulsoterapia ECT, Estimulação do nervo vago ENV, Estimulação cerebral profunda ECP.

Introduction: Congenital Muscular Dystrophy type 1D (MDC1D) is characterized by a hypoglycosylation of α-dystroglycan protein (α-DG), and this may be strongly implicated in increased skeletal muscle tissue degeneration and abnormal brain development, leading to cognitive impairment. However, the pathophysiology of brain involvement is still unclea...

It is estimated that one-third of patients with depression show a lack of adequate response to different pharmacological and non-pharmacological interventions, including electroconvulsive therapy. These patients usually present with lower overall functioning and higher morbidity and mortality. Treatment-resistant depression (TRD) is also associated...

Recent studies have suggested that mitochondrial dysfunction and dysregulated neuroinflammatory pathways are involved in the pathophysiology of major depressive disorder (MDD). Here, we aimed to assess the differences in markers of mitochondrial dynamics, mitophagy, general autophagy, and apoptosis in peripheral blood mononuclear cells (PBMCs) of M...

Susceptibility to psychiatric disorders seems to be influenced by environmental disturbances throughout all stages of life. Epigenetics is described as a key “bridge” between gene and environment, shaping gene expression and phenotype in response to environmental influences. For a long time, it was believed the epigenetic information could not be t...

Precision psychiatry is formally defined as “an emerging approach for treatment and prevention that takes into account each person’s variability in genes, environment, and lifestyle.” Within this new field, predicting response to treatment and therefore selecting the best treatment for a given individual is a priority. Bipolar disorder is a debilit...

One of the main obstacles in developing more effective therapies for bipolar disorder (BD) is the lack of knowledge about its precise pathophysiology. With the advance of translational psychiatry animal modeling have being refined under the neurobiological, pharmacological, and genetic perspectives, and the development of new animal models of psych...

Cognitive impairment is highly prevalent in individuals with bipolar disorders (BD). Studies showed that more the 50% of the euthymic BD patients present some level of cognitive dysfunction. Endophenotypes refer to traits present in nonaffected individuals that can be interpreted as a marker of disease vulnerability, which genetic substrate is pote...

Objective: The present study aims to investigate the effects of Lithium (Li) on manic- and depressive-like behaviors and inflammatory parameters in rats submitted to the bipolar disorder (BD) model induced by ouabain (OUA). Material and methods: Adult male rats received a single intracerebroventricular (ICV) injection of OUA or artificial cerebrosp...

Background Bipolar disorder (BD) is a psychiatric disorder with complex therapy, besides the treatment with antidepressants induce a mania switch. Objective Investigate the effect of the administration of imipramine (IMI) in rats submitted to intracerebroventricular (ICV) administrations of ouabain (OUA). Methods Adult Wistar rats (n = 28) were s...

Stress is related to major depressive disorder (MDD). This study investigated the action that early stress, represented by maternal deprivation (MD), has on the behavior and oxidative stress of Wistar female and male rats. Also, it was evaluated whether changes induced by MD could be reversed by environmental enrichment (EE). Male and female rats w...

Microglia are immune cells found in the central nervous system (CNS) involved in infection combat and cellular debris clean. These glial cells are involved in synaptogenesis during brain development by their interactions with neurons and other glial cells. These relations are associated with the secretion of signaling molecules, such as chemokines...

O Tratado de psiquiatria da Associação Brasileira de Psiquiatria reúne destacados autores dos principais centros de pesquisa e formação de todo o País para trazer aos leitores em língua portuguesa os conhecimentos mais atuais na área. Sob a organização dos doutores Antonio Egidio Nardi, Antônio Geraldo da Silva e João Quevedo, este livro, disponív...

Defective aquaporin4 (AQP4)-mediated glymphatic drainage has been linked to tauopathy and amyloid plaque in Alzheimer’s disease. We now show that brain interleukin33 (IL33) is required for regulation of AQP4 expression in astrocytes, especially those at neuron-facing membrane domain (n-AQP4). First, IL33-deficient (Il33−/−) mice showed a loss of n-...

Introduction The COVID-19 (coronavirus disease 2019)-related pandemic represents a global source of societal and health burden. Yet, the impact of the pandemic on people with severe mental illness, including bipolar disorder (BD), remains unclear, warranting scoping review on the matter. Methods The MEDLINE and EMBASE databases were systematically...

The coronavirus disease of 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome 2 (SARS-CoV-2). In addition to pneumonia, individuals affected by the disease have neurological symptoms. Indeed, SARS-CoV-2 has a neuroinvasive capacity. It is known that the infection caused by SARS-CoV-2 leads to a cytokine storm. An e...

Major depressive disorder (MDD) is one of the most prevalent and debilitating psychiatric disorders, with a large number of patients not showing an effective therapeutic response to available treatments. Several biopsychosocial factors, such as stress in childhood and throughout life, and factors related to biological aging, may increase the suscep...

The importance of tryptophan as a precursor for neuroactive compounds has long been acknowledged. The metabolism of tryptophan along the kynurenine pathway and its involvement in mental disorders is an emerging area in psychiatry. We performed a meta-analysis to examine the differences in kynurenine metabolites in major depressive disorder (MDD), b...

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher lev...

Major depressive disorder is a debilitating mental disorder. Although the etiology is not fully understood, the impairment to the blood-brain barrier (BBB) integrity may be involved. Maternal deprivation was performed in the first 10 postnatal days for 3h/day. Male and female rats were divided into control and maternal deprivation. Maternal depriva...

The aims of this article are to discuss the rationale, design, and procedures of the Greater Houston Area Bipolar Registry (HBR), which aims at contributing to the effort involved in the investigation of neurobiological mechanisms underlying bipolar disorder (BD) as well as to identify clinical and neurobiological markers able to predict BD clinica...