Minimizing adverse events while maintaining clinical improvement in a pediatric attention-deficit/hyperactivity disorder crossover trial with dextroamphetamine and methylphenidate

Key Questions on the Long-Term Utility of Methylphenidate in Paediatric Brain Tumour Survivorship: A Retrospective Clinical Case Series

Methylphenidate has an established role in the management of attention-deficit hyperactivity disorder and attentional deficit secondary to brain injury. Increasingly, methylphenidate is considered for the attentional deficit in paediatric brain tumour survivors. A small number of studies have explored the benefit of methylphenidate in this population; however, studies are of short duration and do not address the impact of medium to long-term use of methylphenidate on intellectual function. We identified six patients who are survivors of a paediatric brain tumour aged 12-18 years with greater than three years of use of methylphenidate for inclusion in a clinical case series. We used this patient cohort to identify key questions to inform a future long-term cohort study. Linear mixed model and reliable change index analyses were performed on the data. Reliable change index analyses showed benefits to working memory (n = 3), processing speed (n = 2), and full-scale IQ (n = 4) performance for some patients. This exploratory case series suggests the potential medium to long-term benefit of methylphenidate in brain tumour survivorship, indicating the need for larger, appropriately powered studies. These patient data, alongside a discussion of learning points from our previously published studies, are used as a conduit for the identification of questions relating to the use of methylphenidate in a paediatric brain tumour.

A meta-analytic review of the impact of ADHD medications on anxiety and depression in children and adolescents

Anxiety and depression are listed as common side effects for medications licensed for treating ADHD in children and adolescents. This meta-analytic review of randomised controlled trials aimed to explore the effect of medications on symptoms of anxiety and depression in children and adolescents with ADHD. A meta-analytic review of ADHD drug trials in children and adolescents was conducted. Random effects meta-analyses were conducted on anxiety and depression outcomes measured by validated psychological scales or side effect rating scales. Only 11% of eligible trials in this review reported anxiety and/or depression as an outcome or side effect, limiting the conclusions of the meta-analyses. Relative to placebo control, no significant effect of medication was found for symptoms of anxiety or depression in randomised controlled trials of ADHD medication in children and adolescents. This review highlights the systemic lack of mental health outcome reporting in child and adolescent ADHD drug trials. The importance of widespread implementation of standardised measurement of mental health outcomes in future trials is discussed.

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.

The Perception of Primary School Teachers Regarding the Pharmacotherapy of Attention Deficit Hyperactivity Disorder

Attention Deficit Hyperactivity Disorder (ADHD) is raising concerns across health systems, affecting about 5% of the school-age population. Therapy usually involves psychostimulants, which are prone to adverse drug reactions (ADRs). Teachers have many contact hours with children and can easily detect behavioral changes upon the beginning of medication. However, few studies have focused on the role of teachers in the management of ADHD children and detection of ADRs. The present work aimed to characterize the perception of primary school teachers regarding the impact of ADHD therapeutics. A questionnaire was constructed focused on teachers’ training regarding ADHD and its therapy; experience with students with ADHD; changes upon beginning of medication; and observation of ADRs. A total of 107 completed questionnaires were obtained. The results indicate that more than 40% of the inquired teachers have received training in ADHD, but in most cases, the theme of therapeutics was absent from that training. The vast majority of teachers (91.6%) have had students with ADHD and observed mood alterations associated with medications. More than 60% of the teachers answered that they are aware of the ADRs and of these, 24% have already detected them in their students. The teachers reported the observed ADRs to parents in 93% of the cases and to doctors in 28% of the cases. In conclusion, the results show the need to reinforce teachers’ training in ADHD and its therapeutics.

Methylphenidate improves weight control in childhood brain tumor survivors with hypothalamic obesity

BACKGROUND

Hypothalamic obesity causes unrelenting weight gain for childhood brain tumor survivors. No single therapy has proven effective for treatment. We aimed to evaluate effectiveness of long-term methylphenidate therapy on body mass index (BMI) change in children with hypothalamic obesity.

METHODS

A retrospective analysis included children with a history of brain tumor and hypothalamic obesity receiving methylphenidate (10-60 mg/day) for hypothalamic obesity. Subjects were evaluated for BMI trajectory before and after methylphenidate start. Given that z-scores can be skewed in severely obese children, we calculated BMI as a percent of the BMI at the 95th percentile for the child's age and gender (BMI% 95th).

RESULTS

Twelve patients with hypothalamic obesity completed methylphenidate therapy for at least 6 months (median 3.1 years, range 1.0-5.8 years). All subjects had a suprasellar tumor (nine [75%] with craniopharyngioma) and pituitary dysfunction. Pretreatment median BMI percent of the 95th percentile was 125.6% (interquartile range [IQR] 25-75: 115.3-138.3%) with BMI z-score of 2.4 (IQR 25-75: 2.1-2.6). Following methylphenidate treatment, there was a 69.9% reduction in the median slope of BMI change. Eleven of 12 patients (92%) had a reduction in the slope of their BMI change on methylphenidate treatment. Postmethylphenidate median BMI percent of the 95th percentile decrease to 115.2% (IQR 25-75: 103.6-121.2%) with median BMI z-score of 2.1 (IQR 25-75: 1.8-2.2). Mild side effects were noted in six patients.

CONCLUSIONS

Methylphenidate use reduced and sustained BMI change in children with hypothalamic obesity. Stimulant therapy is an effective first-line agent for treatment of hypothalamic obesity.

Sleep-Associated Adverse Events During Methylphenidate Treatment of Attention-Deficit/Hyperactivity Disorder: A Meta-Analysis

OBJECTIVE

Sleep disturbances are a feature of attention-deficit/hyperactivity disorder (ADHD) and an adverse event (AE) of methylphenidate treatment. The authors sought to clarify methylphenidate-associated sleep problems and how studies are affected by confounding factors.

DATA SOURCES

Published studies in English collected via online databases and unpublished data from www.clinicaltrials.gov and US Food and Drug Administration websites. Sources were searched from inception to August 2017.

STUDY SELECTION

Included were blinded placebo-controlled studies of youth with ADHD conducted in naturalistic settings, leading to 35 studies yielding 75 observations of sleep-related AEs. These studies comprised 3,079 drug-exposed and 2,606 placebo-treated patients.

DATA EXTRACTION

Two PhD-level reviewers reviewed each study for inclusion. Four PhD/PharmD-level reviewers extracted data in duplicate. Discrepancies were resolved by discussion or, if needed, by the senior author.

RESULTS

Increased pooled relative risks (RRs) were found for methylphenidate-associated sleep-related AEs for insomnia (general), initial insomnia, middle insomnia, combined insomnia, and sleep disorder. Several sample or study design features were significantly associated with the RR for sleep-related AEs and the methylphenidate formulation studied (P < .05). After correction for confounding variables, significant differences among drugs were found for initial insomnia, insomnia (general), and sleep disorder (P < .0001) as the other categories could not be tested due to insufficient studies. The findings also show that the RR and its interpretation are constrained by the placebo AE rate.

CONCLUSIONS

Several types of insomnia and sleep problems are associated with methylphenidate treatment. Study design and sample features influence the RR statistic. By showing that the rate of placebo AEs impacts the RR, this study provides the field with a useful covariate for adjusting RR statistics.

A Review of Methods for Monitoring Adverse Events in Pediatric Psychopharmacology Clinical Trials

Pediatric psychotropic prescription rates are rising, emphasizing the need for careful monitoring of drug safety in this population. Currently, no standardized assessments are used in clinical trials for adverse event (AE) elicitation focused on long-term drug treatment in pediatric patients. Despite a lack of standardized AE elicitation methods in psychiatric clinical trials, it is clear that psychiatric medications have developmentally dependent AEs that differ from those observed in adults. In this review, we discuss the use of general inquiry elicitation, drug-specific checklists, and systematic elicitation scales for AE reporting in pediatric psychopharmacology trials. The checklists evaluated include the Barkley Side Effect Rating Scales (SERS), the Pittsburg side effect rating scale, and the Systematic Monitoring of Adverse events Related to TreatmentS (SMARTS) checklist. The systematic assessment scales discussed include the Systematic Assessment for Treatment of Emergent Events (SAFTEE) and the Safety Monitoring Uniform Report Form (SMURF). We review the advantages and disadvantages of each method and discuss the need for optimal assessment of AEs. AE instruments that are created and utilized for pediatric psychiatric trials must begin to incorporate symptoms that are relevant to this population and account for the nature of the disorders to better characterize treatment-emergent AEs and monitor long-term safety.

Effects of Folic Acid on Appetite in Children with Attention Deficit Hyperactivity Disorder (ADHD) Treated with Methylphenidate: A Randomized Double-Blind Clinical Trial

BACKGROUND

The highly effective medications in treating attention deficit hyperactivity disorder (ADHD) symptoms are stimulants like methylphenidate. However, they have adverse effects like reduced appetite. We investigated the effects of folic acid on reduced appetite caused by the use of methylphenidate in children with ADHD.

METHODS

This randomized double-blind clinical trial evaluated 70 outpatients, aged between 6 and 12 years, with a diagnosis of ADHD. The children were recruited from the Outpatient Child and Adolescent Psychiatric Clinic of Golestan Hospital (Ahwaz, Iran) between 2016 and 2017. The study subjects were randomly assigned to 2 groups: Group 1 received an average dose of methylphenidate (1 mg/kg) plus folic acid (5 mg/d) and Group 2 received an average dose of methylphenidate (1 mg/kg) plus a placebo (5 mg of sucrose) for 8 weeks. Assessments, comprising the Conners Parent Questionnaire, anthropometric measurements, and appetite questionnaire, were conducted by a psychiatrist at baseline and then at 2, 4, 6, and 8 weeks after the medication was started using repeated measure analysis. The data were analyzed with the Mann-Whitney U and ANOVA tests using the SPSS statistical software (v. 18.0).

RESULTS

Age and gender were not associated with the groups. Weight, height, and the body mass index were not changed during the study in both groups. ADHD symptoms significantly decreased in both groups during the trial; however, no difference was observed between the groups. Moreover, appetite was significantly improved in Group 1. Both medications were well tolerated.

CONCLUSION

It seems that folic acid improved the reduced appetite caused by the use of methylphenidate in our children with ADHD. Trial Registration Number: IRCT2016040927304N1.

Psychiatric diagnoses and medication treatment among patients presenting for paediatric weight management: associations with adiposity, aerobic fitness and cardiometabolic health

We compared anthropometry, cardiometabolic risk and aerobic fitness among obese youth in weight management who were diagnosed with one or more psychiatric disorders (PD), with (PD+M) or without (PD-M) a prescribed psychotropic medication with those with no PD (NPD). Physical measures were evaluated at baseline, and psychiatric diagnoses and related medications were identified from medical records. Of 99 patients 64 (65%) had a diagnosed PD, and of those, 23 (36%) had a related medication (PD+M). Compared to NPD, PD-M had a higher body mass index (BMI) (P = 0.003), BMI z-score (P = 0.015), percent body fat (P = 0.005) and waist circumference (P < 0.001), after adjusting for age, but PD+M did not. Cardiometabolic risk did not differ between groups, but aerobic fitness was lower among PD-M (P = 0.001) and PD+M (P = 0.008) compared to NPD. Obese youth in weight management exhibit high rates of psychiatric diagnoses that are associated with lower fitness and higher adiposity and may impact treatment efficacy.

Efficacy, Safety, and Tolerability of an Extended-Release Orally Disintegrating Methylphenidate Tablet in Children 6-12 Years of Age with Attention-Deficit/Hyperactivity Disorder in the Laboratory Classroom Setting

OBJECTIVE

Methylphenidate extended-release orally disintegrating tablets (MPH XR-ODTs) represent a new technology for MPH delivery. ODTs disintegrate in the mouth without water and provide a pharmacokinetic profile that is consistent with once-daily dosing. This study sought to determine the efficacy, safety, and tolerability of this novel MPH XR-ODT formulation in school-age children with attention-deficit/hyperactivity disorder (ADHD) in a laboratory classroom setting.

METHODS

Children aged 6-12 years with ADHD (n = 87) were enrolled in this randomized, multicenter, double-blind, placebo-controlled, parallel, laboratory classroom study. The MPH XR-ODT dose was titrated to an optimized dose during a 4-week open-label period and maintained on that dose for 1 week. Participants (n = 85) were then randomized to receive their optimized dose of MPH XR-ODT or placebo once daily for 1 week (double blind), culminating in a laboratory classroom testing day. Efficacy was evaluated using the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) Attention, Deportment, and Combined scores along with Permanent Product Measure of Performance (PERMP; Attempted and Correct) assessments. Onset and duration of drug action were also evaluated as key secondary endpoints. Safety assessments included adverse events (AEs), physical examinations, electrocardiograms (ECGs), and the Columbia Suicide Severity Rating Scale (C-SSRS).

RESULTS

The average SKAMP-Combined score on the classroom study day was significantly better for the MPH XR-ODT group (n = 43) than for the placebo group (n = 39; p < 0.0001). The effect was evident at 1 hour and lasted through 12 hours postdose. The average SKAMP-Attention, SKAMP-Deportment, PERMP-A, and PERMP-C scores were indicative of significantly greater ADHD symptom control for the MPH XR-ODT group. The most common AEs reported were decreased appetite, upper abdominal pain, headache, insomnia, upper respiratory tract infection, affect lability, irritability, cough, and vomiting.

CONCLUSIONS

MPH XR-ODT was effective and well tolerated for the treatment of children with ADHD in a laboratory classroom setting. Clinical Trial Registry: NCT01835548 ( ClinicalTrials.gov ).

Classics in Chemical Neuroscience: Methylphenidate

As the first drug to see widespread use for the treatment of attention deficit hyperactivity disorder (ADHD), methylphenidate was the forerunner and catalyst to the modern era of rapidly increasing diagnosis, treatment, and medication development for this condition. During its often controversial history, it has variously elucidated the importance of dopamine signaling in memory and attention, provoked concerns about pharmaceutical cognitive enhancement, driven innovation in controlled-release technologies and enantiospecific therapeutics, and stimulated debate about the impact of pharmaceutical sales techniques on the practice of medicine. In this Review, we will illustrate the history and importance of methylphenidate to ADHD treatment and neuroscience in general, as well as provide key information about its synthesis, structure-activity relationship, pharmacological activity, metabolism, manufacturing, FDA-approved indications, and adverse effects.

Amphetamines for attention deficit hyperactivity disorder (ADHD) in children and adolescents

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric conditions affecting children and adolescents. Amphetamines are among the most commonly prescribed medications to manage ADHD. There are three main classes of amphetamines: dexamphetamine, lisdexamphetamine and mixed amphetamine salts, which can be further broken down into short- and long-acting formulations. A systematic review assessing their efficacy and safety in this population has never been conducted.

OBJECTIVES

To assess the efficacy and safety of amphetamines for ADHD in children and adolescents.

SEARCH METHODS

In August 2015 we searched CENTRAL, Ovid MEDLINE, Embase, PsycINFO, ProQuest Dissertation and Theses, and the Networked Digital Library of Theses and Dissertations. We also searched ClinicalTrials.gov, and checked the reference lists of relevant studies and reviews identified by the searches. No language or date restrictions were applied.

SELECTION CRITERIA

Parallel-group and cross-over randomized controlled trials (RCTs) comparing amphetamine derivatives against placebo in a pediatric population (< 18 years) with ADHD.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on participants, settings, interventions, methodology, and outcomes for each included study. For continuous outcomes, we calculated the standardized mean difference (SMD) and for dichotomous outcomes we calculated the risk ratio (RR). Where possible, we conducted meta-analyses using a random-effects model. We also performed a meta-analysis of the most commonly reported adverse events in the primary studies.

MAIN RESULTS

We included 23 trials (8 parallel-group and 15 cross-over trials), with 2675 children aged three years to 17 years. All studies compared amphetamines to placebo. Study durations ranged from 14 days to 365 days, with the majority lasting less than six months. Most studies were conducted in the United States; three studies were conducted across Europe. We judged 11 included studies to be at a high risk of bias due to insufficient blinding methods, failing to account for dropouts and exclusions from the analysis, and failing to report on all outcomes defined a priori. We judged the remaining 12 studies to be at unclear risk of bias due to inadequate reporting.Amphetamines improved total ADHD core symptom severity according to parent ratings (SMD -0.57; 95% confidence interval (CI) -0.86 to -0.27; 7 studies; 1247 children/adolescents; very low quality evidence), teacher ratings (SMD -0.55; 95% CI -0.83 to -0.27; 5 studies; 745 children/adolescents; low quality evidence), and clinician ratings (SMD -0.84; 95% CI -1.32 to -0.36; 3 studies; 813 children/adolescents; very low quality evidence). In addition, the proportion of responders as rated by the Clinical Global Impression - Improvement (CGI-I) scale was higher when children were taking amphetamines (RR 3.36; 95% CI 2.48 to 4.55; 9 studies; 2207 children/adolescents; very low quality evidence).The most commonly reported adverse events included decreased appetite, insomnia/trouble sleeping, abdominal pain, nausea/vomiting, headaches, and anxiety. Amphetamines were associated with a higher proportion of participants experiencing decreased appetite (RR 6.31; 95% CI 2.58 to 15.46; 11 studies; 2467 children/adolescents), insomnia (RR 3.80; 95% CI 2.12 to 6.83; 10 studies; 2429 children/adolescents), and abdominal pain (RR 1.44; 95% CI 1.03 to 2.00; 10 studies; 2155 children/adolescents). In addition, the proportion of children who experienced at least one adverse event was higher in the amphetamine group (RR 1.30; 95% CI 1.18 to 1.44; 6 studies; 1742 children/adolescents; low quality evidence).We performed subgroup analyses for amphetamine preparation (dexamphetamine, lisdexamphetamine, mixed amphetamine salts), amphetamine release formulation (long acting versus short acting), and funding source (industry versus non industry). Between-group differences were observed for proportion of participants experiencing decreased appetite in both the amphetamine preparation (P < 0.00001) and amphetamine release formulation (P value = 0.008) subgroups, as well as for retention in the amphetamine release formulation subgroup (P value = 0.03).

AUTHORS' CONCLUSIONS

Most of the included studies were at high risk of bias and the overall quality of the evidence ranged from low to very low on most outcomes. Although amphetamines seem efficacious at reducing the core symptoms of ADHD in the short term, they were associated with a number of adverse events. This review found no evidence that supports any one amphetamine derivative over another, and does not reveal any differences between long-acting and short-acting amphetamine preparations. Future trials should be longer in duration (i.e. more than 12 months), include more psychosocial outcomes (e.g. quality of life and parent stress), and be transparently reported.

Changes in behavior as side effects in methylphenidate treatment: review of the literature

BACKGROUND

Our review of the scientific literature focused on an analysis of studies describing instances of methylphenidate treatment leading (or not) to behavioral changes in the pediatric, adolescent, and adult populations.

MATERIALS AND METHODS

We conducted a literature search in PubMed, Medline, and Google using the keywords "methylphenidate", "behavioral changes", "adverse effects", and "side effects". A total of 44 studies were identified as reporting on the effects and adverse effects of methylphenidate administration, and were included in the analysis.

RESULTS

Five studies specifically set out to study, record, and discuss changes in behavior. Eight studies did not set out to study behavioral effects, but record and discuss them. A total of 28 studies recorded behavioral effects, but failed to discuss these further. Three studies did not include behavioral effects.

CONCLUSION

This review records what data have been published in respect of changes in behavior in association with the use of methylphenidate. While there is some evidence to suggest that methylphenidate causes changes in behavior, the majority of the studies reviewed paid little or no attention to this issue. Based on the available data, it is impossible to determine the point at which such behavioral effects occur. The frequency of occurrence of behavioral effects is also impossible to determine with certainty. Based on the available data, it is not possible to rule out whether behavioral effects may persist or not persist once treatment is discontinued. In conclusion, despite countless publications and extensive administration, especially to children, we have insufficient data to judge the long-term effects and risks of methylphenidate taking.

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.

Improved quality of life among adolescents with attention-deficit/hyperactivity disorder is mediated by protective factors: a cross sectional survey

BACKGROUND

The aim of this study was to assess the role of protective factors as mediators and/or moderators of the relationship between coexisting emotional and conduct problems and quality of life (QoL) among adolescents with attention-deficit/hyperactivity disorder (ADHD).

METHODS

The sample consisted of 194 adolescents with ADHD. Participants completed measures of individual competencies, family cohesion and social support, and QoL. Coexisting emotional and conduct problems were assessed using the Strength and Difficulties Questionnaire.

RESULTS

Individual competencies and social support mediated the association between emotional and conduct problems and QoL. Family cohesion was associated with both emotional and conduct problems. No moderating effects of protective factors and coexisting problems were found.

CONCLUSIONS

The assessment of individual competencies, social resources, and family cohesion may identify potential treatment goals for adolescents with ADHD and coexisting problems, and may contribute to improvements in QoL.