Luis Carlos Farhat

• Student
• University of São Paulo

Parental anxiety and family accommodation have been implicated in the development and maintenance of child anxiety, yet their relationships with specific child anxiety dimensions remain unclear. This study applied network analysis to examine these interconnections in a clinical sample of 433 children with primary anxiety disorders. The estimated ne...

Trichotillomania is an understudied, underrecognized, and difficult-to-treat psychiatric disorder that affects about 1–2% of the population, predominantly women. This study aimed to characterize the sociodemographic and clinical characteristics of a Swedish cohort of individuals with a diagnosis of trichotillomania assigned in specialist services a...

The transition from adolescence into adulthood is a pivotal phase in a person's life, marking a period of significant social, psychological, and biological changes that can profoundly impact an individual's well‐being and developmental trajectory. During this period, adolescents and young adults face increasing environmental demands from academic o...

Translation of biomarkers to clinical practice is hindered by the significant overlap in neurobiological measures between ADHD cases and controls. A risk-informed design can enhance the utility and validation of ADHD biomarkers by highlighting differences between individuals with ADHD and those without at differential risk. Participants were 2511 c...

Objective: To evaluate the comparative efficacy of pharmacological interventions for children and adolescents with a dual diagnosis of persistent tic disorders or Tourette disorder and attention-deficit/hyperactivity disorder (TD + ADHD). Methods: We searched CENTRAL, Embase, PubMed, PsycInfo, Web of Sciences, ClinicalTrials.gov, and WHO ICTRP up t...

Research demonstrates the important role of genetic factors in attention-deficit/hyperactivity disorder (ADHD). DNA sequencing of families provides a powerful approach for identifying de novo (spontaneous) variants, leading to the discovery of hundreds of clinically informative risk genes for other childhood neurodevelopmental disorders. This appro...

Background Trichotillomania (TTM) and excoriation disorder (ED) are impairing obsessive-compulsive related disorders that are common in the general population and for which there are no clear first-line medications, highlighting the need to better understand the underlying biology of these disorders to inform treatments. Given the importance of gen...

Importance Stimulants (methylphenidate and amphetamines) are often prescribed at unlicensed doses for adults with attention-deficit/hyperactivity disorder (ADHD). Whether dose escalation beyond US Food and Drug Administration recommendations is associated with positive risk benefits is unclear. Objective To investigate the impact, based on average...

Data on incidence, prevalence and burden of ADHD are crucial for clinicians, patients, and stakeholders. We present the incidence, prevalence, and burden of ADHD globally and across countries from 1990 to 2019 from the Global Burden of Disease (GBD) study. We also: (1) calculated the ADHD prevalence based on data actually collected as opposed to th...

Objective: Previous population-based studies have identified associations between childhood neurodevelopmental traits and depression in childhood, adolescence, and young adulthood. However, neurodevelopmental traits are highly correlated with each other, which could confound associations when traits are examined in isolation. The authors sought to...

Attention-deficit/hyperactivity disorder (ADHD) is a common and impairing neurodevelopmental disorder in which genetic factors play an important role. DNA sequencing of parent-child trios provides a powerful approach for identifying de novo (spontaneous) variants, which has led to the discovery of hundreds of clinically informative risk genes for o...

Epidemiological studies of excoriation disorder have reported different prevalence estimates for this condition, limiting our understanding of its public health impact. We performed a systematic review and meta-analysis to collate epidemiological studies of excoriation disorder. We aimed to estimate the pooled prevalence and the female-to-male rati...

Self-injurious thoughts and behaviours (SITBs) have been associated with dysfunction of the Autonomic Nervous System (ANS) in children and young people, suggesting that objective ANS measures may aid assessment of suicide risk, but a systematic synthesis of this literature is currently lacking. Methods Following a pre-registered protocol (PROSPERO...

Background Robust synthesis of evidence to support treatment recommendations for preschoolers with attention‐deficit/hyperactivity disorder (ADHD) is lacking. The aim of this systematic review and meta‐analysis was to review currently available evidence to evaluate the efficacy and acceptability of stimulants for preschool children with ADHD. Meth...

Trichotillomania (hair-pulling disorder) and excoriation (skin-picking) disorder are body-focused repetitive behaviors, which often first present in adolescence and cause distress and impairment into adulthood. Few studies have examined the clinical characteristics of the co-occurrence of these conditions across the lifespan. We examined cross-sect...

Neurodevelopmental disorders – including attention‐deficit/hyperactivity disorder (ADHD), autism spectrum disorder, communication disorders, intellectual disability, motor disorders, specific learning disorders, and tic disorders – manifest themselves early in development. Valid, reliable and broadly usable biomarkers supporting a timely diagnosis...

Background: In clinical practice guidelines there is no consensus about the medications that should be initially offered to children and young people with Tourette's syndrome. To provide a rigorous evidence base that could help guide decision making and guideline development, we aimed to compare the efficacy, tolerability, and acceptability of pha...

Introduction: Pharmacotherapy is an important component of the multimodal treatment of attention-deficit/hyperactivity disorder (ADHD). Cardiovascular safety of medications for ADHD is of concern from a clinical and public health standpoint. We aim to conduct a network meta-analysis (NMA) comparing the effects of available medications for ADHD on...

Recreational and problem gambling have been linked with adverse health and functioning outcomes among adolescents. Youth may gamble and engage in other risk-taking behaviors in casinos. There are limited data available regarding casino gambling in high-school students, and factors linked to adolescent gambling in casinos have yet to be systematical...

Background. Self-injurious thoughts and behaviours (SITBs) have been associated with dysfunction of the Autonomic Nervous System (ANS) in children and young people, suggesting that objective ANS measures may aid assessment of suicide risk, but a systematic synthesis of this literature is currently lacking. Methods. Following a pre-registered protoc...

Epidemiological studies have provided varying prevalence estimates of trichotillomania (TTM) and other hair-pulling behaviors. We performed a systematic review and meta-analysis to provide data-driven prevalence estimates of TTM and hair-pulling. PubMed, PsycInfo and Embase were searched on June 2020 (updated in November 2021). Studies reporting th...

Objective: There is limited evidence about the cross-cultural validity of autistic symptoms in school-aged children in Brazil. Methods: We translated the Childhood Autism Spectrum Test scale to Brazilian Portuguese and performed factor analyses to investigate the factor structure of parent-reported autistic symptoms in a large sample (N = 8571)...

Brazil has been severely affected by the COVID-19 pandemic with one of the largest numbers of youth impacted by school closure globally. This longitudinal online survey assessed emotional problems in children and adolescents aged 5–17 years living in Brazil during the COVID-19 pandemic. Recruitment occurred between June to November 2020 and partici...

The desire to escape from pressures/anxiety represents an important motivation for problematic engagement with short-term rewarding behaviors that could contribute to the development of recognized and candidate behavioral addictions, including problematic shopping, a prevalent condition among youth in the U.S.A. characterized by excessive shopping...

Tourette syndrome (TS) is now recognized as a common neurodevelopmental disorder affecting children and adults. It has gained increasingly public awareness and scientific interest worldwide. Knowledge of its clinical presentation and available treatment approaches has increased dramatically over the last two decades. Tourette Syndrome offers a uniq...

Objectives: Studies have suggested Brain-Derived Neurotrophic Factors (BDNF) increase after electroconvulsive therapy (ECT) although they were methodologically limited and enrolled small sample sizes. We aimed at updating a systematic review and meta-analysis to explore BDNF changes after ECT for the treatment of depression. Methods: PubMed, Psy...

Clinical guidelines currently recommend practitioners titrate stimulant medications, i.e., methylphenidate (MPH) and amphetamines (AMP), to the dose that maximizes symptom control without eliciting intolerable adverse events (AEs) when treating attention-deficit/hyperactivity disorder (ADHD) in school-aged children/adolescents. However, robust evid...

Objectives: Whether parental age, i.e., paternal or maternal, at childbirth is associated with risk of bipolar disorder (BD) in offspring remains unclear. We conducted a meta-analysis of observational studies to address this gap. Methods: PubMed, PsycINFO, Embase and Web of Science were searched up to June, 2021. Studies investigating the associ...

Vesicular monoamine transporter type 2 (VMAT2) inhibitors may be an effective therapy for chronic tic disorders (CTD), including Tourette syndrome (TS), but there has not been a meta‐analysis compiling available evidence from randomized controlled trials (RCTs). We performed a systematic review and meta‐analysis to evaluate the efficacy, acceptabil...

Objective A lack of universal definitions for response and remission in pediatric obsessive-compulsive disorder (OCD) has hampered the comparability of results across trials. To address this problem, we conducted an individual participant data diagnostic test accuracy meta-analysis to evaluate the discriminative ability of the Children’s Yale-Brown...

Background Previous research investigating the overlap between attention‐deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (henceforth, autism) symptoms in population samples have relied on latent variable modeling in which averaged scores representing dimensions were derived from observed symptoms. There are no studies evaluating...

Motivational characteristics such as excitement-seeking are key components of models of addiction, including problem gambling. Previous studies have established associations between excitement-seeking and problem gambling in youth. However, these studies have employed dimensional psychological assessments which are unlikely to be routinely administ...

In this issue, Rodrigues et al. (2020) present a systematic review with meta‐analyses that reports the efficacy of five treatments for children with attention‐deficit hyperactivity disorder symptoms in the context of autism spectrum disorder – (a) methylphenidate; (b) atomoxetine; (c) guanfacine; (d) aripiprazole; and (e) risperidone. In this comme...

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation approach which has been increasingly used as an investigational tool in neuroscience. In social and affective neuroscience research, the prefrontal cortex has been primarily targeted, since this brain region is critically involved in complex psychobiological processe...

Background Trichotillomania (TTM) is a difficult‐to‐treat psychiatric condition with no first‐line medications approved by the Food and Drug Administration. Individuals with TTM often feel that clinicians know little about this disorder. Here, we present an updated meta‐analysis of randomized controlled trials (RCTs) examining treatments for TTM....

Objective To examine the efficacy of pharmacological treatments for restricted and repetitive behaviors (RRBs) in autism spectrum disorder (ASD). Method We searched PubMed, Embase, and CENTRAL to identify all double-blind, randomized, placebo-controlled trials that examined the efficacy of pharmacological agents in the treatment of autism spectrum...

Although the term has been relatively ill defined in psychiatric research, "biomarker" is typically considered a measurable objective characteristic that can predict clinical outcomes such as risk, diagnosis, subgroups, severity, prognosis, and response to treatment.1 Among several fields of medicine, such as cardiology and oncology, biomarkers hav...

Gambling is prevalent among adolescents and adolescents are vulnerable to experiencing gambling-related problems. Although problem gambling and suicidal behavior have been linked in adults and self-injurious behaviors may predict future suicidality, prior studies have not investigated relationships between problem-gambling severity and self-injurio...

Objectives: In clinical trials of pediatric trichotillomania (TTM), three instruments are typically employed to rate TTM severity: (1) the Massachusetts General Hospital Hair Pulling Scale (MGH-HPS), (2) the National Institute of Mental Health Trichotillomania Severity Scale (NIMH-TSS), and (3) the Trichotillomania Scale for Children (TSC). These i...

Objectives Bipolar disorder is frequently associated with cognitive impairment even during euthymia. Previous studies have reported significant impairments in functional and quality of life outcomes and a possible relationship between these variables and cognitive performance. Cognitive rehabilitation interventions have been proposed to address the...