Efficacy of stimulants for preschool attention-deficit/hyperactivity disorder: A systematic review and meta-analysis.

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. Methods: We searched electronic databases (CENTRAL, Embase, PubMed) from the database inception to March, 2022; and clinical trial registries through WHO ICTRP from the database inception to July, 2022, and selected double-blinded randomized controlled trials (RCTs) that compared stimulants against placebo for the treatment of preschoolers (age ≤ 7 years) with ADHD. Change in ADHD symptom severity was the primary outcome (efficacy) and all-cause dropout rates (acceptability) was the secondary outcome. Data were pooled with random-effects models weighted by the inverse of the variance. Risk of bias of individual studies were assessed with the Cochrane Risk of Bias tool version 2. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess the quality of evidence. This study is registered with PROSPERO (CRD42022348597). Results: Five RCTs (three methylphenidate immediate-release, one methylphenidate extended-release, and one lisdexamfetamine) were included. The analysis of efficacy was based on 489 participants. Meta-analysis of change in ADHD symptom severity demonstrated a significant effect in favor of stimulants over placebo (standardized mean difference = -0.59; 95% CI -0.77, -0.41; p < 0.0001). There was no evidence of heterogeneity but some concerns about publication bias. Regardless, the confidence of evidence was considered moderate. For acceptability, stimulants did not lead to an increased rate of all-cause discontinuation rates in comparison to placebo (OR = 0.59; 95% CI 0.15, 2.37; p = 0.45) but the confidence of estimate was very low. Conclusions: Our findings demonstrated that stimulants are efficacious in reducing ADHD symptoms among preschool children. Clinicians should consider the use of stimulants when making treatment recommendations for preschoolers with ADHD.

Annual research review: A meta-analysis of the worldwide prevalence of mental disorders in children and adolescents.

BACKGROUND: The literature on the prevalence of mental disorders affecting children and adolescents has expanded significantly over the last three decades around the world. Despite the field having matured significantly, there has been no meta-analysis to calculate a worldwide-pooled prevalence and to empirically assess the sources of heterogeneity of estimates. METHODS: We conducted a systematic review of the literature searching in PubMed, PsycINFO, and EMBASE for prevalence studies of mental disorders investigating probabilistic community samples of children and adolescents with standardized assessments methods that derive diagnoses according to the DSM or ICD. Meta-analytical techniques were used to estimate the prevalence rates of any mental disorder and individual diagnostic groups. A meta-regression analysis was performed to estimate the effect of population and sample characteristics, study methods, assessment procedures, and case definition in determining the heterogeneity of estimates. RESULTS: We included 41 studies conducted in 27 countries from every world region. The worldwide-pooled prevalence of mental disorders was 13.4% (CI 95% 11.3-15.9). The worldwide prevalence of any anxiety disorder was 6.5% (CI 95% 4.7-9.1), any depressive disorder was 2.6% (CI 95% 1.7-3.9), attention-deficit hyperactivity disorder was 3.4% (CI 95% 2.6-4.5), and any disruptive disorder was 5.7% (CI 95% 4.0-8.1). Significant heterogeneity was detected for all pooled estimates. The multivariate metaregression analyses indicated that sample representativeness, sample frame, and diagnostic interview were significant moderators of prevalence estimates. Estimates did not vary as a function of geographic location of studies and year of data collection. The multivariate model explained 88.89% of prevalence heterogeneity, but residual heterogeneity was still significant. Additional meta-analysis detected significant pooled difference in prevalence rates according to requirement of funcional impairment for the diagnosis of mental disorders. CONCLUSIONS: Our findings suggest that mental disorders affect a significant number of children and adolescents worldwide. The pooled prevalence estimates and the identification of sources of heterogeneity have important implications to service, training, and research planning around the world.

Association between UCP2 A55V polymorphism and risk of cardiovascular events in patients with multi-vessel coronary arterial disease.

BACKGROUND: UCP2 (uncoupling protein 2) plays an important role in cardiovascular diseases and recent studies have suggested that the A55V polymorphism can cause UCP2 dysfunction. The main aim was to investigate the association of A55V polymorphism with cardiovascular events in a group of 611 patients enrolled in the Medical, Angioplasty or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease and preserved left ventricular function. METHODS: The participants of the MASS II were genotyped for the A55V polymorphism using allele-specific PCR assay. Survival curves were calculated with the Kaplan-Meier method and evaluated with the log-rank statistic. The relationship between baseline variables and the composite end-point of cardiac death, acute myocardial infarction (AMI), refractory angina requiring revascularization and cerebrovascular accident were assessed using a Cox proportional hazards survival model. RESULTS: There were no significant differences for baseline variables according genotypes. After 2 years of follow-up, dysglycemic patients harboring the VV genotype had higher occurrence of AMI (p=0.026), Death+AMI (p=0.033), new revascularization intervention (p=0.009) and combined events (p=0.037) as compared with patients carrying other genotypes. This association was not evident in normoglycemic patients. CONCLUSIONS: These findings support the hypothesis that A55V polymorphism is associated with UCP2 functional alterations that increase the risk of cardiovascular events in patients with previous coronary artery disease and dysglycemia.