The acute effect of methylphenidate in Brazilian male children and adolescents with ADHD: a randomized clinical trial

Methylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children and adolescents with ADHD find it difficult to pay attention and they are hyperactive and impulsive. Methylphenidate is the psychostimulant most often prescribed, but the evidence on benefits and harms is uncertain. This is an update of our comprehensive systematic review on benefits and harms published in 2015.

OBJECTIVES

To assess the beneficial and harmful effects of methylphenidate for children and adolescents with ADHD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases and two trials registers up to March 2022. In addition, we checked reference lists and requested published and unpublished data from manufacturers of methylphenidate.

SELECTION CRITERIA

We included all randomised clinical trials (RCTs) comparing methylphenidate versus placebo or no intervention in children and adolescents aged 18 years and younger with a diagnosis of ADHD. The search was not limited by publication year or language, but trial inclusion required that 75% or more of participants had a normal intellectual quotient (IQ > 70). We assessed two primary outcomes, ADHD symptoms and serious adverse events, and three secondary outcomes, adverse events considered non-serious, general behaviour, and quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and risk of bias assessment for each trial. Six review authors including two review authors from the original publication participated in the update in 2022. We used standard Cochrane methodological procedures. Data from parallel-group trials and first-period data from cross-over trials formed the basis of our primary analyses. We undertook separate analyses using end-of-last period data from cross-over trials. We used Trial Sequential Analyses (TSA) to control for type I (5%) and type II (20%) errors, and we assessed and downgraded evidence according to the GRADE approach.

MAIN RESULTS

We included 212 trials (16,302 participants randomised); 55 parallel-group trials (8104 participants randomised), and 156 cross-over trials (8033 participants randomised) as well as one trial with a parallel phase (114 participants randomised) and a cross-over phase (165 participants randomised). The mean age of participants was 9.8 years ranging from 3 to 18 years (two trials from 3 to 21 years). The male-female ratio was 3:1. Most trials were carried out in high-income countries, and 86/212 included trials (41%) were funded or partly funded by the pharmaceutical industry. Methylphenidate treatment duration ranged from 1 to 425 days, with a mean duration of 28.8 days. Trials compared methylphenidate with placebo (200 trials) and with no intervention (12 trials). Only 165/212 trials included usable data on one or more outcomes from 14,271 participants. Of the 212 trials, we assessed 191 at high risk of bias and 21 at low risk of bias. If, however, deblinding of methylphenidate due to typical adverse events is considered, then all 212 trials were at high risk of bias.

PRIMARY OUTCOMES

methylphenidate versus placebo or no intervention may improve teacher-rated ADHD symptoms (standardised mean difference (SMD) -0.74, 95% confidence interval (CI) -0.88 to -0.61; I² = 38%; 21 trials; 1728 participants; very low-certainty evidence). This corresponds to a mean difference (MD) of -10.58 (95% CI -12.58 to -8.72) on the ADHD Rating Scale (ADHD-RS; range 0 to 72 points). The minimal clinically relevant difference is considered to be a change of 6.6 points on the ADHD-RS. Methylphenidate may not affect serious adverse events (risk ratio (RR) 0.80, 95% CI 0.39 to 1.67; I² = 0%; 26 trials, 3673 participants; very low-certainty evidence). The TSA-adjusted intervention effect was RR 0.91 (CI 0.31 to 2.68).

SECONDARY OUTCOMES

methylphenidate may cause more adverse events considered non-serious versus placebo or no intervention (RR 1.23, 95% CI 1.11 to 1.37; I² = 72%; 35 trials 5342 participants; very low-certainty evidence). The TSA-adjusted intervention effect was RR 1.22 (CI 1.08 to 1.43). Methylphenidate may improve teacher-rated general behaviour versus placebo (SMD -0.62, 95% CI -0.91 to -0.33; I² = 68%; 7 trials 792 participants; very low-certainty evidence), but may not affect quality of life (SMD 0.40, 95% CI -0.03 to 0.83; I² = 81%; 4 trials, 608 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

The majority of our conclusions from the 2015 version of this review still apply. Our updated meta-analyses suggest that methylphenidate versus placebo or no-intervention may improve teacher-rated ADHD symptoms and general behaviour in children and adolescents with ADHD. There may be no effects on serious adverse events and quality of life. Methylphenidate may be associated with an increased risk of adverse events considered non-serious, such as sleep problems and decreased appetite. However, the certainty of the evidence for all outcomes is very low and therefore the true magnitude of effects remain unclear. Due to the frequency of non-serious adverse events associated with methylphenidate, the blinding of participants and outcome assessors is particularly challenging. To accommodate this challenge, an active placebo should be sought and utilised. It may be difficult to find such a drug, but identifying a substance that could mimic the easily recognised adverse effects of methylphenidate would avert the unblinding that detrimentally affects current randomised trials. Future systematic reviews should investigate the subgroups of patients with ADHD that may benefit most and least from methylphenidate. This could be done with individual participant data to investigate predictors and modifiers like age, comorbidity, and ADHD subtypes.

Treatments for child and adolescent attention deficit hyperactivity disorder in low and middle-income countries: A narrative review

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that affects approximately 2-7 % of children globally and is associated with a myriad of difficulties that have long-term consequences. Most children and adolescents live in low- and middle-income countries (LMICs), but there are few reports and no consolidation of findings on ADHD treatment outcomes in this population. We conducted a review of ADHD treatment literature for children and adolescents living in LMICs.

METHODS

Studies were identified using databases (PsychoINFO, Pubmed, MEDLINER, EMBASE, Global Health, Academic Search Complete, Google Scholar). The initial search produced 139 articles. These were filtered for language, title, abstract, and full-text keyword identification to yield a final 20 articles to be included in this review.

RESULTS

Reports on outcomes of both psychological and pharmacological treatment were relatively sparse, particularly the former, which mostly referred to parent training and multimodal programs in pre-school children. Most evidence exists for the benefit of methylphenidate-IR with a few reports on other agents, including clonidine, atomoxetine, and lisdexamfetamine. Methylphenidate is the most common agent to treat ADHD in youth in LMICs. Younger age, combined subtype, and comorbid oppositional defiant disorder were associated with poorer treatment outcome.

CONCLUSION

Access to treatment for ADHD is overall limited in LMICs and varied among individual countries. Pharmacological treatments were generally more available than psychological interventions. Several barriers including stigma, cost, and lack of resources were reported to impact treatment acceptance. More research in LMICs is needed to improve and expand mental health services in these regions.

Effects of the DRD4 -521 C/T SNP on Local Neural Activity and Functional Connectivity in Children With ADHD

Objective: The present study aimed to investigate the effects of the dopamine receptor D4 (DRD4) -521 C/T single-nucleotide polymorphism on brain function among children with attention deficit hyperactivity disorder (ADHD) and to evaluate whether brain function is associated with behavioral performance among this demographic. Methods: Using regional homogeneity, fractional amplitude low-frequency fluctuation, and functional connectivity as measurement indices, we compared differences in resting-state brain function between 34 boys with ADHD in the TT homozygous group and 37 boys with ADHD in the C-allele carrier group. The Conners' Parent Rating Scale, the SNAP-IV Rating Scale, the Stroop Color Word Test, the go/no-go task, the n-back task, and the working memory index within the Wechsler Intelligence Scale for Children-Fourth Edition were selected as comparative indicators in order to test effects on behavioral performance. Results: We found that TT homozygotes had low behavioral performance as compared with C-allele carriers. The regional homogeneity for TT homozygotes decreased in the right middle occipital gyrus and increased in the right superior frontal gyrus as compared with C-allele carriers. In addition, the right middle occipital gyrus and the right superior frontal gyrus were used as the seeds of functional connectivity, and we found that the functional connectivity between the right middle occipital gyrus and the right cerebellum decreased, as did the functional connectivity between the right superior frontal gyrus and the angular gyrus. No statistically significant differences were observed in the respective brain regions when comparing the fractional amplitudes for low-frequency fluctuation between the two groups. Correlation analyses demonstrated that the fractional amplitude low-frequency fluctuation in the precentral gyrus for TT homozygotes were statistically significantly correlated with working memory. Conclusions: We found differing effects of DRD4 -521 C/T polymorphisms on brain function among boys with ADHD. These findings promote our understanding of the genetic basis for neurobiological differences observed among children with ADHD, but they must be confirmed in larger samples.

The dopamine transporter role in psychiatric phenotypes

The dopamine transporter (DAT) is one of the most relevant and investigated neurotransmitter transporters. DAT is a plasma membrane protein which plays a homeostatic role, controlling both extracellular and intracellular concentrations of dopamine (DA). Since unbalanced DA levels are known to be involved in numerous mental disorders, a wealth of investigations has provided valuable insights concerning DAT role into normal brain functioning and pathological processes. Briefly, this extensive but non-systematic review discusses what is recently known about the role of SLC6A3 gene which encodes the dopamine transporter in psychiatric phenotypes. DAT protein, SLC6A3 gene, animal models, neuropsychology, and neuroimaging investigations are also concisely discussed. To conclude, current challenges are reviewed in order to provide perspectives for future studies.

Effects of methylphenidate on executive functioning in attention-deficit/hyperactivity disorder across the lifespan: a meta-regression analysis

Attention-deficit/hyperactivity disorder (ADHD) in childhood and adulthood is often treated with the psychostimulant methylphenidate (MPH). However, it is unknown whether cognitive effects of MPH depend on age in individuals with ADHD, while animal studies have suggested age-related effects. In this meta-analysis, we first determined the effects of MPH on response inhibition, working memory and sustained attention, but our main goal was to examine whether these effects are moderated by age. A systematic literature search using PubMed, PsycINFO, Web of Science and MEDLINE for double-blind, placebo-controlled studies with MPH resulted in 25 studies on response inhibition (n = 775), 13 studies on working memory (n = 559) and 29 studies on sustained attention (n = 956) (mean age range 4.8-50.1 years). The effects of MPH on response inhibition [effect size (ES) = 0.40, p < 0.0001, 95% confidence interval (CI) 0.22-0.58], working memory (ES = 0.24, p = 0.053, 95% CI 0.00-0.48) and sustained attention (ES = 0.42, p < 0.0001, 95% CI 26-0.59) were small to moderate. No linear or quadratic age-dependencies were observed, indicating that effects of MPH on executive functions are independent of age in children and adults with ADHD. However, adolescent studies are lacking and needed to conclude a lack of an age-dependency across the lifespan.

Methylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children with ADHD find it difficult to pay attention, they are hyperactive and impulsive.Methylphenidate is the drug most often prescribed to treat children and adolescents with ADHD but, despite its widespread use, this is the first comprehensive systematic review of its benefits and harms.

OBJECTIVES

To assess the beneficial and harmful effects of methylphenidate for children and adolescents with ADHD.

SEARCH METHODS

In February 2015 we searched six databases (CENTRAL, Ovid MEDLINE, EMBASE, CINAHL, PsycINFO, Conference Proceedings Citations Index), and two trials registers. We checked for additional trials in the reference lists of relevant reviews and included trials. We contacted the pharmaceutical companies that manufacture methylphenidate to request published and unpublished data.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing methylphenidate versus placebo or no intervention in children and adolescents aged 18 years and younger with a diagnosis of ADHD. At least 75% of participants needed to have an intellectual quotient of at least 70 (i.e. normal intellectual functioning). Outcomes assessed included ADHD symptoms, serious adverse events, non-serious adverse events, general behaviour and quality of life.

DATA COLLECTION AND ANALYSIS

Seventeen review authors participated in data extraction and risk of bias assessment, and two review authors independently performed all tasks. We used standard methodological procedures expected within Cochrane. Data from parallel-group trials and first period data from cross-over trials formed the basis of our primary analyses; separate analyses were undertaken using post-cross-over data from cross-over trials. We used Trial Sequential Analyses to control for type I (5%) and type II (20%) errors, and we assessed and downgraded evidence according to the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach for high risk of bias, imprecision, indirectness, heterogeneity and publication bias.

MAIN RESULTS

The studies.We included 38 parallel-group trials (5111 participants randomised) and 147 cross-over trials (7134 participants randomised). Participants included individuals of both sexes, at a boys-to-girls ratio of 5:1, and participants' ages ranged from 3 to 18 years across most studies (in two studies ages ranged from 3 to 21 years). The average age across all studies was 9.7 years. Most participants were from high-income countries.The duration of methylphenidate treatment ranged from 1 to 425 days, with an average duration of 75 days. Methylphenidate was compared to placebo (175 trials) or no intervention (10 trials). Risk of Bias.All 185 trials were assessed to be at high risk of bias. Primary outcomes. Methylphenidate may improve teacher-rated ADHD symptoms (standardised mean difference (SMD) -0.77, 95% confidence interval (CI) -0.90 to -0.64; 19 trials, 1698 participants; very low-quality evidence). This corresponds to a mean difference (MD) of -9.6 points (95% CI -13.75 to -6.38) on the ADHD Rating Scale (ADHD-RS; range 0 to 72 points; DuPaul 1991a). A change of 6.6 points on the ADHD-RS is considered clinically to represent the minimal relevant difference. There was no evidence that methylphenidate was associated with an increase in serious (e.g. life threatening) adverse events (risk ratio (RR) 0.98, 95% CI 0.44 to 2.22; 9 trials, 1532 participants; very low-quality evidence). The Trial Sequential Analysis-adjusted intervention effect was RR 0.91 (CI 0.02 to 33.2).

SECONDARY OUTCOMES

Among those prescribed methylphenidate, 526 per 1000 (range 448 to 615) experienced non-serious adverse events, compared with 408 per 1000 in the control group. This equates to a 29% increase in the overall risk of any non-serious adverse events (RR 1.29, 95% CI 1.10 to 1.51; 21 trials, 3132 participants; very low-quality evidence). The Trial Sequential Analysis-adjusted intervention effect was RR 1.29 (CI 1.06 to 1.56). The most common non-serious adverse events were sleep problems and decreased appetite. Children in the methylphenidate group were at 60% greater risk for trouble sleeping/sleep problems (RR 1.60, 95% CI 1.15 to 2.23; 13 trials, 2416 participants), and 266% greater risk for decreased appetite (RR 3.66, 95% CI 2.56 to 5.23; 16 trials, 2962 participants) than children in the control group.Teacher-rated general behaviour seemed to improve with methylphenidate (SMD -0.87, 95% CI -1.04 to -0.71; 5 trials, 668 participants; very low-quality evidence).A change of seven points on the Child Health Questionnaire (CHQ; range 0 to 100 points; Landgraf 1998) has been deemed a minimal clinically relevant difference. The change reported in a meta-analysis of three trials corresponds to a MD of 8.0 points (95% CI 5.49 to 10.46) on the CHQ, which suggests that methylphenidate may improve parent-reported quality of life (SMD 0.61, 95% CI 0.42 to 0.80; 3 trials, 514 participants; very low-quality evidence).

AUTHORS' CONCLUSIONS

The results of meta-analyses suggest that methylphenidate may improve teacher-reported ADHD symptoms, teacher-reported general behaviour, and parent-reported quality of life among children and adolescents diagnosed with ADHD. However, the low quality of the underpinning evidence means that we cannot be certain of the magnitude of the effects. Within the short follow-up periods typical of the included trials, there is some evidence that methylphenidate is associated with increased risk of non-serious adverse events, such as sleep problems and decreased appetite, but no evidence that it increases risk of serious adverse events.Better designed trials are needed to assess the benefits of methylphenidate. Given the frequency of non-serious adverse events associated with methylphenidate, the particular difficulties for blinding of participants and outcome assessors point to the advantage of large, 'nocebo tablet' controlled trials. These use a placebo-like substance that causes adverse events in the control arm that are comparable to those associated with methylphenidate. However, for ethical reasons, such trials should first be conducted with adults, who can give their informed consent.Future trials should publish depersonalised individual participant data and report all outcomes, including adverse events. This will enable researchers conducting systematic reviews to assess differences between intervention effects according to age, sex, comorbidity, type of ADHD and dose. Finally, the findings highlight the urgent need for large RCTs of non-pharmacological treatments.

Toward quality care in ADHD: defining the goals of treatment

OBJECTIVE

Therapeutic goals for chronic mental disorders like major depressive disorder (MDD) and schizophrenia have evolved in parallel with the growing medical knowledge about the course and treatment of these disorders. Although the knowledge base regarding the clinical course of ADHD, a chronic psychiatric disorder, has evolved beyond symptomatic improvement and short-term treatment response, long-term goals, such as functional remission, have not yet been clearly defined.

METHOD

A PubMed literature search was conducted to investigate the therapeutic goals of pharmacologic treatment referenced in the published literature from January 1998 through February 2010 using the following commonly used ADHD treatments as keywords: amphetamine, methylphenidate, atomoxetine, lisdexamfetamine, guanfacine, and clonidine. This search was then combined with an additional search that included the following outcome keywords: remission, relapse, remit, response, normal, normalization, recovery, and effectiveness.

RESULTS

Our search identified 102 publications. The majority (88.2% [90/102]) of these contained predefined criteria for treatment response. Predefined criteria for normalization and remission and/or relapse were presented in 4.9% (5/102), 12.7% (13/102), and 3.9% (4/102) of publications, respectively. There was a lack of consistency between the instruments used to measure outcomes as well as the criteria used to define treatment response, normalization, and remission as well as relapse.

CONCLUSION

The therapeutic goals in treating ADHD should address optimal treatment outcomes that go beyond modest reductions of ADHD symptoms to include syndromatic, symptomatic, and functional remission. Future work should focus on reliable and valid tools to measure these outcomes in the clinical trial setting.

Outcomes of child psychiatric treatment

OBJECTIVE

The aim of this study was to investigate outcomes of child psychiatric outpatient treatment as usual and to identify outcome predictors, with special regard to attention-deficit/hyperactivity disorder (ADHD), mood disorder, obsessive-compulsive disorder and conduct disorder.

METHOD

Routinely collected data from 12 613 outpatients between July 2006 and January 2010 in Stockholm, Sweden were analysed. The outcome measure was change in Children's Global Assessment Scale (CGAS) ratings between first visit and case closure (∆CGAS).

RESULTS

CGAS improved during the course of treatment across all diagnostic groups, ranging from a mean change of 4 (mental retardation) to 16 (suicide attempts). ∆CGAS was two times higher in the mood disorder group compared with the ADHD group. In the mood disorder group, several psychotherapies were associated with better outcome but not medication. In the ADHD group, psychotherapeutic interventions were also associated with better outcome, but those who received treatment with central stimulants received less non-medical interventions.

CONCLUSION

Whereas the functional impairment and the level of improvement in mood disorder corresponded to previous efficacy studies, the ADHD patients were more impaired and improved less after treatment. This should prompt a critical discussion as to whether ADHD patients receive the best available treatment in CAMHS in Stockholm and elsewhere.

What works where? A systematic review of child and adolescent mental health interventions for low and middle income countries

PURPOSE

Child and adolescent mental health (CAMH) problems are common and serious all over the world and are linked to pre-mature deaths and serious dysfunction in adult life. Effective interventions have been developed in high income countries (HIC), but evidence from low income settings is scarce and scattered. The aim of this paper is to identify the most promising interventions in the area of global CAMH.

METHOD

A systematic review of all randomised controlled trials in CAMH in low and middle income countries (LAMIC) was carried out and supplemented by 1a level evidence from HIC as well as suitable information from child programme evaluations and adult studies in LAMIC.

RESULTS

In behavioural disorders parent training is a highly promising intervention, which can successfully improve children's compliance and bring down rates of conduct problems significantly. In young children cognitive, emotional and behavioural development can be enhanced through nutritional supplements and by stimulation through play, praise and reading. Trauma treatments can bring positive results even in severely traumatised children, who remain in unstable living conditions. In developmental disorders, there are successful prevention strategies as well as programmes that bring children out of isolation and improve their independence. Some classroom-based interventions for adolescents have reduced symptoms of common mental disorders as well as risk taking behaviours.

CONCLUSIONS

While many results are still tentative the evidence suggests that it is possible to develop affordable and feasible interventions that significantly improve the lives of affected children, their families and their communities around the world.

Catechol-O-methyltransferase valine158methionine polymorphism moderates methylphenidate effects on oppositional symptoms in boys with attention-deficit/hyperactivity disorder

BACKGROUND

The catechol-O-methyltransferase enzyme plays a key role in the function of prefrontal cortex, accounting for most of the degradation of dopamine. Previous studies have documented the improvement of oppositional symptoms in attention-deficit/hyperactivity disorder (ADHD) patients with methylphenidate (MPH) treatment. However, the effect of the COMT gene in the response to MPH on oppositional symptoms has not been investigated.

METHODS

A total of 251 children with ADHD fulfilled inclusion criteria to participate in the study. Dosages of short-acting MPH were augmented until no further clinical improvement was detected or until there were significant adverse events (MPH dose always > .3 mg/kg/day). The outcome measure was the parent-rated oppositional subscale of the Swanson, Nolan and Pelham Scale-Version IV (SNAP-IV). The scale was applied by child psychiatrists blinded to genotype at baseline and in the first and third months. The COMT valine158methionine polymorphism was genotyped by polymerase chain reaction based methods.

RESULTS

We detected significant improvement in SNAP-IV oppositional scores from baseline to the first and three months of treatment [n = 112; F(2,231) = 5.35, p = .005]. A significant effect of the presence of methionine allele in oppositional defiant disorder scores during treatment [F(1,148) = 5.02, p = .027] and a significant interaction between the methionine allele and treatment over time for the SNAP-IV oppositional scores during this period of treatment [F(2,229) = 6.40, p = .002] were both observed.

CONCLUSIONS

These results suggest an effect of the COMT genotype on the trajectory of oppositional defiant disorder symptoms improvement with MPH treatment in boys with ADHD.

Atomoxetine acts as an NMDA receptor blocker in clinically relevant concentrations

BACKGROUND AND PURPOSE

There is increasing evidence that not only the monoaminergic but also the glutamatergic system is involved in the pathophysiology of attention-deficit hyperactivity disorder (ADHD). Hyperactivity of glutamate metabolism might be causally related to a hypoactive state in the dopaminergic system. Atomoxetine, a selective noradrenaline reuptake inhibitor, is the first non-stimulant approved for the treatment of this disorder. Here we have evaluated the effects of atomoxetine on glutamate receptors in vitro.

EXPERIMENTAL APPROACH

The whole-cell configuration of the patch-clamp technique was used to analyse the effect of atomoxetine on N-methyl-d-aspartate (NMDA) receptors in cultured rodent cortical and hippocampal neurons as well as on NMDA receptors heterologously expressed in human TsA cells.

KEY RESULTS

Atomoxetine blocked NMDA-induced membrane currents. Half-maximal inhibition emerged at about 3 microM which is in the range of clinically relevant concentrations found in plasma of patients treated with this drug. The inhibition was voltage-dependent, indicating an open-channel blocking mechanism. Furthermore, the inhibitory potency of atomoxetine did not vary when measured on NMDA receptors from different brain regions or with different subunit compositions.

CONCLUSIONS AND IMPLICATIONS

The effective NMDA receptor antagonism by atomoxetine at low micromolar concentrations may be relevant to its clinical effects in the treatment of ADHD. Our data provide further evidence that altered glutamatergic transmission might play a role in ADHD pathophysiology.

Association between tryptophan hydroxylase 2, performance on a continuance performance test and response to methylphenidate in ADHD participants

The main objective of this study was to examine neuropsychological mechanisms mediating the association between tryptophan hydroxylase 2 (TPH2) and attention deficit hyperactivity disorder (ADHD). A continuous performance test (T.O.V.A.) was administered to 344 participants diagnosed with DSM IV ADHD who were also genotyped for eight TPH2 intronic SNPs. Association between TPH2 (single SNPs and haplotypes), ADHD, and performance on the T.O.V.A. were tested using robust family-based association tests as implemented in two statistical genetic programs: UNPHASED and PBAT. Association was only observed between an eight locus haplotype and ADHD DSM IV combined type III (global P = 0.036). Robust association was observed between TPH2 single SNPs (and haplotypes) and performance on the T.O.V.A., especially Errors of Omission (eight locus haplotypes, global P = 0.038). Significant associations were also observed between TPH2 and improvement (before-after scores) in T.O.V.A. Total Response Variability scores following acute methylphenidate challenge (eight locus haplotypes, global P = 0.009). Using the MFBAT program, significant multivariate association was observed between single SNPs and haplotypes [eight locus haplotypes and all four T.O.V.A. variables (PBAT-GEE P = 0.013)]. The two most common TPH2 eight locus haplotypes were in a Yin Yang configuration and the Yang haplotype was the risk haplotype for both DSM IV ADHD and deficits in neuropsychological performance. The current investigation shows that risk for ADHD conferred by TPH2 variants is partially mediated by serotonergic mechanisms impacting some facets of executive function. Importantly, improvement in T.O.V.A. performance, especially on Response Time Variability, following methylphenidate was also associated with TPH2.

Treatment and prevention of mental disorders in low-income and middle-income countries

We review the evidence on effectiveness of interventions for the treatment and prevention of selected mental disorders in low-income and middle-income countries. Depression can be treated effectively in such countries with low-cost antidepressants or with psychological interventions (such as cognitive-behaviour therapy and interpersonal therapies). Stepped-care and collaborative models provide a framework for integration of drug and psychological treatments and help to improve rates of adherence to treatment. First-generation antipsychotic drugs are effective and cost effective for the treatment of schizophrenia; their benefits can be enhanced by psychosocial treatments, such as community-based models of care. Brief interventions delivered by primary-care professionals are effective for management of hazardous alcohol use, and pharmacological and psychosocial interventions have some benefits for people with alcohol dependence. Policies designed to reduce consumption, such as increased taxes and other control strategies, can reduce the population burden of alcohol abuse. Evidence about the efficacy of interventions for developmental disabilities is inadequate, but community-based rehabilitation models provide a low-cost, integrative framework for care of children and adults with chronic mental disabilities. Evidence for mental health interventions for people who are exposed to conflict and other disasters is still weak-especially for interventions in the midst of emergencies. Some trials of interventions for prevention of depression and developmental delays in low-income and middle-income countries show beneficial effects. Interventions for depression, delivered in primary care, are as cost effective as antiretroviral drugs for HIV/AIDS. The process and effectiveness of scaling up mental health interventions has not been adequately assessed. Such research is needed to inform the continuing process of service reform and innovation. However, we recommend that policymakers should act on the available evidence to scale up effective and cost-effective treatments and preventive interventions for mental disorders.

Attention-deficit/hyperactivity disorder in a diverse culture: do research and clinical findings support the notion of a cultural construct for the disorder?

There is still some debate in the literature whether Attention-Deficit Disorder/Hyperactivity (ADHD) is best conceptualized as a biological disorder or if it is best understood as a cultural construct. This review aims to contribute to disentangle this issue assessing clinical and research data on ADHD in a complete diverse culture from a developing country. We performed a systematic computerized review of the literature on ADHD in Brazil. All investigations were included if dealing with ADHD prevalence, etiology, symptomatological construct, or treatment. Findings were compared to those from studies in developed countries. The prevalence rates of ADHD (5.8% using DSM-IV criteria, 1.5% using ICD-10), the bi-dimensional factor construct extracted from factor analyses (inattention and hyperactivity/impulsivity), the pattern of ADHD comorbidity in clinical samples, the family genetic data suggesting a 39% family transmission in clinical samples and the role of some potential candidate genes in dopaminergic and noradrenergic systems, as well as data on the efficacy of methylphenidate in the disorder are all very similar to findings from developed countries. Taken together, these findings suggest that ADHD is not a cultural construct, reinforcing the importance of applying similar research methodology in different cultures to make findings comparable.