Short-term side effects of stimulant medication are increased in preschool children with attention-deficit/hyperactivity disorder: a double-blind placebo-controlled study

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 In addition, we checked reference lists and requested published and unpublished data from manufacturers of methylphenidate.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.

Efficacy and Safety of Lisdexamfetamine in Preschool Children With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To evaluate the acute efficacy, safety, and tolerability of lisdexamfetamine dimesylate (LDX) vs placebo (PBO) in preschool-aged children with attention-deficit/hyperactivity disorder (ADHD).

METHOD

This phase 3, double-blind, fixed-dose study randomly assigned children (aged 4-5 years) with ADHD to 6 weeks of LDX (5, 10, 20, 30 mg) or PBO. The prespecified primary (change from baseline at week 6 in ADHD Rating Scale IV, Preschool version, total score [ADHD-RS-IV-PS-TS]) and key secondary (Clinical Global Impression-Improvement [CGI-I] score at week 6) efficacy endpoints were assessed using linear mixed-effects models for repeated measures. Safety and tolerability assessments included treatment-emergent adverse events (TEAEs) and changes in pulse and blood pressure (BP).

RESULTS

The study comprised 199 participants randomly asigned 5:5:5:5:6 to receive 5, 10, 20, 30 mg LDX or PBO, respectively. Least squares (LS) mean (95% CI) treatment difference at week 6 between pooled LDX (10, 20, 30 mg) and PBO was statistically significant for ADHD-RS-IV-PS-TS change (-5.9 [-11.01, -0.78], p = .0242; effect size [ES], -0.43). CGI-I scores improved (ie, 1-2 on CGI-I) in 41.7% for pooled LDX and 24.3% for PBO (p = .0857). The LS mean (95% CI) treatment difference between pooled LDX and PBO for CGI-I score at week 6 was -0.6 (-1.03, -0.16; p = .0074; ES, -0.52). Frequency of TEAEs was 46.6% across all 4 LDX doses vs 42.2% with PBO; the most frequent TEAEs were decreased appetite (13.7% vs 8.9%, respectively) and irritability (9.6% vs 0%). Discontinuations because of TEAEs were 5.5% for all LDX doses and 4.4% for PBO. Mean ± SD pulse/BP changes from baseline at week 6/early termination were numerically greater with LDX vs PBO (pulse beats/min: 2.7 ± 10.79 vs 1.2 ± 9.90; systolic BP, mm Hg: 1.0 ± 7.51 vs 0.3 ± 6.06; diastolic BP, mm Hg: 1.7 ± 5.90 vs 0.0 ± 6.88).

CONCLUSION

In children aged 4 to 5 years with ADHD, LDX was more efficacious than PBO in reducing symptoms. The observed ES for change in ADHD-RS-IV-PS-TS appears to be smaller in magnitude than has been reported for studies of LDX conducted in older children and adolescents. LDX was generally well tolerated, and no new safety signals were identified.

CLINICAL TRIAL REGISTRATION INFORMATION

Safety and Efficacy Study in Preschool Children Aged 4-5 Years With Attention-Deficit/Hyperactivity Disorder; http://www.

CLINICALTRIALS

gov; NCT03260205.

Pharmacotherapy for Preschool Children with Attention Deficit Hyperactivity Disorder (ADHD): Current Status and Future Directions

In this review, we consider issues relating to the pharmacological treatment of young children with attention deficit hyperactivity disorder (ADHD). ADHD in preschool-age children has a profound impact on psychosocial function and developmental trajectory. Clinical studies on pharmacotherapies for ADHD in young children have expanded rapidly in the past 2 decades, providing some evidence of efficacy for both psychostimulant and non-psychostimulant medications. However, preschool children may be more susceptible to adverse effects of medications, including growth reduction and cardiovascular side effects. Many questions remain regarding the long-term safety and effectiveness of these interventions; thus more research is needed to help clinicians evaluate the risk-benefit ratio for preschoolers with ADHD. As this body of knowledge grows, providers should consider the level of impairment caused by current symptoms in the risk-benefit analysis. Families should be educated not just about potential effects of medication but known complications of untreated ADHD; parents will likely not fully appreciate the long-term psychological effects of chronic behavioral problems and underachievement on a young child. A blanket "wait and see" approach should be avoided, in order to prevent a permanent loss of self-esteem and motivation that may affect some children throughout their lifespan.

Methylphenidate-Induced Enuresis: 3 Case Reports

ABSTRACT

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children and adolescents. Methylphenidate (MPH) is one of the most widely used drugs in the treatment of ADHD. Enuresis can occur comorbidly with ADHD. However, enuresis is sometimes seen in patients with ADHD as an adverse effect of MPH treatment. In contrast, in some cases, MPH reportedly improves enuresis in patients with ADHD comorbid with enuresis. The literature is contradictory with regard to the relationship between MPH and enuresis. This report presents the cases of 3 children with ADHD who displayed enuresis during MPH treatment.

Adverse drug events related to mood and emotion in paediatric patients treated for ADHD: A meta-analysis

BACKGROUND

ADHD is frequently comorbid with anxiety and mood disorders, which may increase the severity of inattention and hyperactivity symptoms. Emotional symptoms (anxiety, irritability, mood lability) also affect patients without comorbidity or emerge as adverse drug events. The influence of ADHD drugs on emotional symptoms demands investigation to improve therapies.

METHODS

Systematic review of trials reporting adverse events in patients pharmacologically treated for ADHD. Meta-analysis of the occurrence of irritability, anxiety, apathy, reduced talk, sadness, crying, emotional lability, biting nails, staring, perseveration, euphoria. Meta-regression analysis.

RESULTS

Forty-five trials were meta-analysed. The most frequently reported outcomes were irritability, anxiety, sadness, and apathy. Methylphenidates, especially immediate-release formulations, were most studied; amphetamines were half as studied and were predominantly mixed amphetamine salts. Reports on atomoxetine were scant. Meta-analysis showed that methylphenidates reduced the risk of irritability, anxiety, euphoria, whereas they worsened the risk of apathy and reduced talk; amphetamines worsened the risk of emotional lability. Factors influencing risks were study year and design, patients' sex and age, drug dose and release formulation.

LIMITATIONS

Possible discrepancy between adverse events as indicated in clinical trials and as summarised herein. Confounding due to the aggregation of drugs into groups; uninvestigated sources of bias; incomplete lists of adverse events; lack of observations on self-injury.

CONCLUSIONS

Methylphenidates appeared safer than amphetamines, although younger patients and females may incur higher risks, especially with high-dose, immediate-release methylphenidates. Only atomoxetine holds a black-box warning, but amphetamines and methylphenidates also did not show a safe profile regarding mood and emotional symptoms.

Improvements in Irritability with Open-Label Methylphenidate Treatment in Youth with Comorbid Attention Deficit/Hyperactivity Disorder and Disruptive Mood Dysregulation Disorder

OBJECTIVE

The purpose of this open-label study was to examine the effects of long-acting methylphenidate (MPH) treatment on irritability and related emotional symptoms associated with disruptive mood dysregulation disorder (DMDD) in youth with comorbid attention-deficit/hyperactivity disorder (ADHD).

METHODS

The sample included 22 medication-free male and female subjects (ages 9-15) who met criteria for both DMDD and ADHD. Participants underwent a 4-week trial of long-acting MPH treatment (Concerta^®), with weekly dosing increases until a therapeutic dose was reached. Repeated measures t-tests were used to compare pre- and posttreatment ratings of primary and secondary measures. The primary outcome was self-report irritability. Secondary outcomes included parent and child ratings of emotional frequency, emotional lability, and negative affect (NA). Multiple regression was used to examine the impact baseline hyperactivity, age, gender, race, socioeconomic status, or comorbid diagnosis had on treatment outcomes.

RESULTS

Significant improvements (medium to large effect sizes) in child-rated irritability as well as parent and child ratings of emotional lability, NA, and anger were found. As anticipated, ADHD symptoms also improved. While a majority of the sample saw improvement in child-rated irritability (71%), symptoms worsened a small proportion (19%), and an even smaller portion experienced no change (10%). No demographics, psychiatric comorbidities, or severity of ADHD symptoms influenced treatment outcomes.

CONCLUSIONS

Study findings suggest that MPH treatment significantly improved mood and emotional symptoms associated with DMDD comorbid with ADHD. These findings, coupled with good tolerability in this open-label pilot study supports further research into the use of MPH as a first-line treatment for DMDD. Future work examining MPH treatment of youth with DMDD with and without comorbid ADHD is needed.

From Clinical Application to Cognitive Enhancement: The Example of Methylphenidate

Methylphenidate (MPD) is a central nervous system (CNS) stimulant, which belongs to the phenethylamine group and is mainly used in the treatment of attention deficit hyperactive disorder (ADHD). However, a growing number of young individuals misuse or abuse MPD to sustain attention, enhance intellectual capacity and increase memory. Recently, the use of MPD as a cognitive enhancement substance has received much attention and raised concerns in the literature and academic circles worldwide. The prescribing frequency of the drug has increased sharply as consequence of the more accurate diagnosis of the ADHD and the popularity of the drug itself due to its beneficial short-term effect. However, careful monitoring is required, because of possible abuse. In this review different aspects concerning the use of MPD have been approached. Data showing its abuse among college students are given, when the drug is prescribed short term beneficial effects and side effects are provided; moreover studies on animal-models suggesting long lasting negative effects on healthy brains are discussed. Finally, emphasis is given to the available formulations and pharmacology.

Effects of Methylphenidate on Sleep Functioning in Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To examine the effects of stimulant medication on the sleep functioning of children with attention-deficit/hyperactivity disorder (ADHD) and identify predictors of sleep problems as a side effect of taking stimulant medication.

METHOD

One hundred sixty-three stimulant-naïve children (72% boys) aged 7 to 11 years diagnosed with ADHD (120 with ADHD predominantly inattentive type, 43 with ADHD combined type) participated in a 4-week, randomized, double-blind, placebo-controlled trial of once-daily (long-acting) methylphenidate (MPH). Parents completed weekly side-effect ratings including an item related to sleep problems.

RESULTS

Ten percent of patients had parent-rated sleep problems before the initiation of medication. Rates of parent-rated sleep problems during MPH titration generally increased with increasing MPH dose (placebo: 8%; low dose: 18%; medium dose: 15%; high dose: 25%). Differences emerged between children with (n = 16) or without (n = 147) preexisting sleep problems. Although 23% of children without preexisting sleep problems went on to have sleep problems at the highest MPH dose, only 37.5% of children with preexisting sleep problems still had sleep problems at the highest MPH dose. Lower weight and lower body mass index (BMI) were associated with increased sleep problems during MPH titration.

CONCLUSION

This study demonstrated a general association between increased MPH dose and increased sleep problems in children with ADHD, particularly for children of lower weight/BMI. However, a substantial proportion of children with preexisting sleep difficulties no longer had sleep problems on the highest MPH dose, which may help explain mixed findings reported to date in studies examining the impact of MPH on sleep functioning in children with ADHD and suggests that MPH dose titration should not be avoided solely on the basis of a child's premorbid sleep problems. Future research is needed to replicate and extend these findings to more specific domains of sleep functioning and to identify differences between children with persistent or improved sleep functioning as a result of MPH use.

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.

Meta-Analysis: Reduced Risk of Anxiety with Psychostimulant Treatment in Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Anxiety is a commonly reported side-effect of psychostimulant treatment. Our goal was to quantify the risk of anxiety as a side effect of psychostimulant treatment for attention-deficit/hyperactivity disorder (ADHD).

METHODS

We conducted a PubMed search to identify all double-blind, randomized, placebo-controlled trials examining the efficacy of psychostimulant medications in the treatment of children with ADHD. We used a fixed-effects meta-analysis to examine the risk ratio of anxiety reported as a side effect in children treated with psychostimulants compared with those treated with placebo. We used stratified subgroup analysis and meta-regression to examine the effects of stimulant type, dosage, duration of use, and trial design on the measured risk of anxiety.

RESULTS

We identified 23 studies involving 2959 children with ADHD for inclusion in our meta-analysis. The risk of anxiety associated with psychostimulant treatment was significantly lower than that experienced with placebo (relative risk [RR] = 0.86 [95% CI: 0.77, 0.95], z = -2.90, p < 0.05). Higher doses of psychostimulants were associated with a reduced measured risk of anxiety of psychostimulants when compared with placebo (β = -0.0039 [95% CI: -0.00718, -0.00064], z = -2.34, p = 0.019).

CONCLUSIONS

Meta-analysis suggests that treatment with psychostimulants significantly reduced the risk of anxiety when compared with placebo. This finding does not rule out the possibility that some children experience increased anxiety when treated with psychostimulants, but suggests that those risks are outweighed by the number of children who experience improvement in anxiety symptoms (possibly as a secondary effect of improved control of ADHD symptoms). Clinicians should consider rechallenging children with ADHD who report new-onset or worsening anxiety with psychostimulants, as these symptoms are much more likely to be coincidental rather than caused by psychostimulants.

Meta-Analysis: Risk of Tics Associated With Psychostimulant Use in Randomized, Placebo-Controlled Trials

OBJECTIVE

Clinical practice currently restricts the use of psychostimulant medications in children with tics or a family history of tics for fear that tics will develop or worsen as a side effect of treatment. Our goal was to conduct a meta-analysis to examine the risk of new onset or worsening of tics as an adverse event of psychostimulants in randomized, placebo-controlled trials.

METHOD

We conducted a PubMed search to identify all double-blind, randomized, placebo-controlled trials examining the efficacy of psychostimulant medications in the treatment of children with attention-deficit/hyperactivity disorder (ADHD). We used a fixed effects meta-analysis with risk ratio of new onset or worsening tics in children treated with psychostimulants compared to placebo. We used stratified subgroup analysis and meta-regression to examine the effects of stimulant type, dose, duration of treatment, recorder of side effect data, trial design, and mean age of participants on the measured risk of tics.

RESULTS

We identified 22 studies involving 2,385 children with ADHD for inclusion in our meta-analysis. New onset tics or worsening of tic symptoms were commonly reported in the psychostimulant (event rate = 5.7%, 95% CI = 3.7%-8.6%) and placebo groups (event rate = 6.5%, 95% CI = 4.4%-9.5%). The risk of new onset or worsening of tics associated with psychostimulant treatment was similar to that observed with placebo (risk ratio = 0.99, 95% CI = 0.78-1.27, z = -0.05, p = .962). Type of psychostimulant, dose, duration of treatment, recorder, and participant age did not affect risk of new onset or worsening of tics. Crossover studies were associated with a significantly greater measured risk of tics with psychostimulant use compared to parallel group trials.

CONCLUSION

Meta-analysis of controlled trials does not support an association between new onset or worsening of tics and psychostimulant use. Clinicians may want to consider rechallenging children who report new onset or worsening of tics with psychostimulant use, as these symptoms are much more likely to be coincidental rather than caused by psychostimulants.

Does Methylphenidate Affect Cystometric Parameters in Spontaneously Hypertensive Rats?

PURPOSE

Methylphenidate (MPH) is one of the most commonly prescribed psychostimulants for attention deficit hyperactivity disorder (ADHD). However, there is limited research on its effects on lower urinary tract function. This study investigated changes in cystometric parameters after intragastric administration of MPH in conscious spontaneously hypertensive rats (SHRs), an animal model of ADHD.

METHODS

Fourteen- to 16-week-old male SHRs (n=10), weighing between 280 and 315 g, were used. Three micturition cycles were recorded before administering MPH. One hour after each intragastric MPH injection, three cycles of cystometrogram were obtained in the awake condition. Various cystometric parameters were evaluated, including basal pressure (BP), maximal pressure (MP), threshold pressure (TP), bladder capacity (BC), micturition volume (MV), micturition interval (MI), and residual volume (RV). The data were analyzed using paired Student t-tests.

RESULTS

Five SHRs were each administered a dose of 3-mg/kg MPH, and the other five received a dose of 6-mg/kg MPH. BP and MP increased significantly in the rats that received the 3-mg/kg MPH injection, but not in those that received the 6-mg/kg injection. BC, MV, and MI significantly increased in the rats that received the 6-mg/kg MPH injection, but not in those that received the 3-mg/kg injection. There were no significant changes in TP after either injection.

CONCLUSIONS

Significant increases in BC, MV, and MI after the 6-mg/kg MPH injection suggest that the peripheral and the central nervous systems may play important roles in bladder function in those receiving MPH for ADHD.

Treatment strategies for ADHD in preschool and school-age children

This review presents current best-evidence treatment options for children with attention-deficit hyperactivity disorder (ADHD), including a review of current literature on the efficacy and safety of psychostimulant medications, particularly methylphenidate, used in treating preschoolers and school-age children with ADHD.

Withholding and canceling a response in ADHD adolescents

BACKGROUND

Deficient response inhibition in situations involving a trade-off between response execution and response stopping is a hallmark of attention deficit hyperactive disorder (ADHD). There are two key components of response inhibition; reactive inhibition where one attempts to cancel an ongoing response and prospective inhibition is when one withholds a response pending a signal to stop. Prospective inhibition comes into play prior to the presentation of the stop signal and reactive inhibition follows the presentation of a signal to stop a particular action. The aim of this study is to investigate the neural activity evoked by prospective and reactive inhibition in adolescents with and without ADHD.

METHODS

Twelve adolescents with ADHD and 12 age-matched healthy controls (age range 9-18) were imaged while performing the stop signal task (SST).

RESULTS

Reactive inhibition activated right inferior frontal gyrus (IFG) in both groups. ADHD subjects activated IFG bilaterally. In controls, prospective inhibition invoked preactivation of the same part of right IFG that activated during reactive inhibition. In ADHD subjects, prospective inhibition was associated with deactivation in this region. Controls also deactivated the medial prefrontal cortex (MPFC) during prospective inhibition, whereas ADHD subjects activated the same area.

DISCUSSION

This pattern of activity changes in the same structures, but in opposite directions, was also evident across all phases of the task in various task-specific areas like the superior and middle temporal gyrus and other frontal areas.

CONCLUSION

Differences between ADHD and control participants in task-specific and default mode structures (IFG and MPFC) were evident during prospective, but not during reactive inhibition.

Methylphenidate side effect profile is influenced by genetic variation in the attention-deficit/hyperactivity disorder-associated CES1 gene

OBJECTIVE

A naturalistic, prospective study of the influence of genetic variation on dose prescribed, clinical response, and side effects related to stimulant medication in 77 children with attention-deficit/hyperactivity disorder (ADHD) was undertaken. The influence of genetic variation of the CES1 gene coding for carboxylesterase 1A1 (CES1A1), the major enzyme responsible for the first-pass, stereoselective metabolism of methylphenidate, was investigated.

METHODS

Parent- and teacher-rated behavioral questionnaires were collected at baseline when the children were medication naïve, and again at 6 weeks while they were on medication. Medication dose, prescribed at the discretion of the treating clinician, and side effects, were recorded at week 6. Blood and saliva samples were collected for genotyping. Single nucleotide polymorphisms (SNPs) were selected in the coding, non-coding and the 3' flanking region of the CES1 gene. Genetic association between CES1 variants and ADHD was investigated in an expanded sample of 265 Irish ADHD families. Analyses were conducted using analysis of covariance (ANCOVA) and logistic regression models.

RESULTS

None of the CES1 gene variants were associated with the dose of methylphenidate provided or the clinical response recorded at the 6 week time point. An association between two CES1 SNP markers and the occurrence of sadness as a side effect of short-acting methylphenidate was found. The two associated CES1 markers were in linkage disequilibrium and were significantly associated with ADHD in a larger sample of ADHD trios. The associated CES1 markers were also in linkage disequilibrium with two SNP markers of the noradrenaline transporter gene (SLC6A2).

CONCLUSIONS

This study found an association between two CES1 SNP markers and the occurrence of sadness as a side effect of short-acting methylphenidate. These markers were in linkage disequilibrium together and with two SNP markers of the noradrenaline transporter gene.

Interventions for preschool children at high risk for ADHD: a comparative effectiveness review

OBJECTIVES

The US Agency for Healthcare Research and Quality sponsored a comparative effectiveness review of interventions for preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD).

METHODS

Medline, Cochrane CENTRAL, Embase, PsycInfo, and Education Resources Information Center were searched from 1980 to November 24, 2011. Selected studies were comparative, and enrolled children <6 years with clinically significant disruptive behavior, including ADHD. The interventions evaluated were parent behavior training (PBT), combined home and school/day care interventions, and methylphenidate use. Data were extracted by using customized software. Two independent raters evaluated studies as good, fair, or poor by using the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies Risk of Bias. Overall strength of evidence (SOE) was rated for each intervention's effectiveness, accounting for study design, systematic error, consistency of results, directness of evidence, and certainty regarding outcome.

RESULTS

Fifty-five studies were examined. Only studies examining PBT interventions could be pooled statistically using meta-analysis. Eight "good" studies examined PBT, total n = 424; SOE was high for improved child behavior, standardized mean difference = -0.68 (95% confidence interval: -0.88 to -0.47), with minimal heterogeneity among studies. Only 1 good study evaluated methylphenidate, total n = 114; therefore, SOE for methylphenidate was low. Combined home and school/day care interventions showed inconsistent results. The literature reported adverse effects for methylphenidate but not for PBT.

CONCLUSIONS

With more studies consistently documenting effectiveness, PBT interventions have greater evidence of effectiveness than methylphenidate for treatment of preschoolers at risk for ADHD.

Pharmacotherapy of pediatric attention-deficit/hyperactivity disorder

This article describes the practical use of available attention-deficit/hyperactivity disorder (ADHD) pharmacotherapies, their formulations and durations of action, and the extent of Food and Drug Administration approvals. It provides data on short-term and long-term safety of these medications, their use in ADHD with comorbid conditions, and strategies for formulating individualized, effective, and well-tolerated pharmacotherapy treatment plans. A clinical vignette focusing on a male child with ADHD is presented. Summaries are presented of ADHD pharmacotherapies and Food and Drug Administration approval status, atomoxetine and stimulant comparator trials, adverse effects and ADHD pharmacotherapy, and delivery system and duration of effect.

Attention deficit hyperactivity disorder and sensory modulation disorder: a comparison of behavior and physiology

Children with attention deficit hyperactivity disorder (ADHD) are impulsive, inattentive and hyperactive, while children with sensory modulation disorder (SMD), one subtype of Sensory Processing Disorder, have difficulty responding adaptively to daily sensory experiences. ADHD and SMD are often difficult to distinguish. To differentiate these disorders in children, clinical ADHD, SMD, and dual diagnoses were assessed. All groups had significantly more sensory, attention, activity, impulsivity, and emotional difficulties than typical children, but with distinct profiles. Inattention was greater in ADHD compared to SMD. Dual diagnoses had more sensory-related behaviors than ADHD and more attentional difficulties than SMD. SMD had more sensory issues, somatic complaints, anxiety/depression, and difficulty adapting than ADHD. SMD had greater physiological/electrodermal reactivity to sensory stimuli than ADHD and typical controls. Parent-report measures identifying sensory, attentional, hyperactive, and impulsive difficulties varied in agreement with clinician's diagnoses. Evidence suggests ADHD and SMD are distinct diagnoses.

The evidence-based pharmacological treatment of paediatric ADHD

Attention deficit hyperactivity disorder (ADHD) is common in children, adolescents, and adults, with extensive research establishing it as a valid neurobiological disorder. Without intervention, ADHD can result in significant impairment throughout the lifespan for the individuals it afflicts. Fortunately, multiple evidence-based options are available for the treatment of ADHD, including several efficacious pharmacotherapies. The role of medication, including stimulants as well as non-stimulants, is well-documented by an extensive body of literature. Although there may be less enthusiasm for behavioural and other psychosocial interventions as stand-alone treatments for moderate to severe ADHD, they are recommended as first-line treatment for ADHD management in preschool-aged children, for those patients with mild symptoms, and as an adjunct to medication in patients with comorbid disorders or suboptimal responses to pharmacotherapy. When planning treatment for individuals with ADHD, the potential risks associated with the available interventions must be carefully balanced against the risks of not treating, or not treating adequately. The treatment plan must also include ongoing re-assessment of the effectiveness of and the need for continued therapy. Recent practice parameters provide further specific guidance for the evidence-based assessment and treatment of children and adolescents with ADHD.

Age-grouped differences in adverse drug events from psychotropic medication

OBJECTIVE

This review aims to detail specific psychotropic medication treatment differences in adverse drug events (ADEs) between children, adolescents, and adults.

METHOD

A thorough data-based search of ADEs was made, augmented by findings from approved and updated U.S. Food and Drug Administration (FDA) drug labels, controlled clinical trial reports, and from FDA information on ADEs at scheduled public hearings.

RESULTS

Children were found to generally exhibit more ADEs to psychotropic medication than adolescents and adults. These ADEs primarily include altered growth velocity, rash, vomiting, dystonia, tics, affect lability, activation, metabolic blood test abnormalities, sedation, sialorrhea, and electrocardiogram irregularities.

CONCLUSION

Children have more biological vulnerabilities than older individuals, which could account for their greater rate of ADEs to psychotropic medication treatment.

Changes in emotions related to medication used to treat ADHD. Part I: literature review

OBJECTIVE

To summarize the literature investigating changes in emotional expression (EE) as a function of pharmacotherapy in the treatment of ADHD and to differentiate emotional effects related to ADHD pharmacotherapy from emotional effects related to ADHD as a disorder.

METHOD

English language articles published from January 1, 1988, through August 31, 2008 were identified through a PubMed literature search using the search terms attention, ADHD, hyperactive, hyperkinesis, and ADD cross-referenced with medication terms amphetamine, lisdexamfetamine, methylphenidate , guanfacine, atomoxetine, and clonidine. The search was limited to randomized, controlled trials. Abstracts from all identified articles were selected for further review if they met criteria including (a) presence of a placebo arm, (b) children ≤ 18 years of age, (c) ≥ 20 participants, and (b) study design elements that would allow reviewers to determine whether EE phenomena were specifically attributable to medication effects versus alternative explanations (e.g., time, maturation, baseline comorbidity, selection artifacts, or treatments other than the medication-placebo contrast). Qualifying full-text articles were reviewed for prespecified EE terms.

RESULTS

Of 148 articles that met selection criteria, 47 reported varying types of EE. Eight of these included two active treatment arms. Hence, 55 data sets were identified. Patterns of change in EE in studies meeting search criteria are discussed. Data sets that reported accounts of EE by the percentage of patients were compiled and further analyzed for specific medication classes. The changes in EE are further discussed as (a) salutary or detrimental, (b) associated with time of day or circumscribed, and (c) presumed to be caused by pharmacological effects.

CONCLUSIONS

Definitive methodologies for assessing the presence of changes in EE in clinical trials and guidelines for the evaluation of EE in clinical practice are yet to be established and are needed. Such guidelines could be used by clinicians to monitor positive and negative changes in emotion when patients are taking medications for their ADHD.

The occurrence of adverse drug reactions reported for attention deficit hyperactivity disorder (ADHD) medications in the pediatric population: a qualitative review of empirical studies

BACKGROUND

To review empirical studies of adverse drug reactions (ADRs) reported to be associated with the use of medications generally licensed for treatment of attention deficit hyperactivity disorder (ADHD) symptoms in the pediatric population.

METHODS

PubMed, Embase, and PsycINFO(®) databases were searched from origin until June 2011. Studies reporting ADRs from amphetamine derivates, atomoxetine, methylphenidate, and modafinil in children from birth to age 17 were included. Information about ADR reporting rates, age and gender of the child, type, and seriousness of ADRs, setting, study design, ADR assessors, authors, and funding sources were extracted.

RESULTS

The review identified 43 studies reporting ADRs associated with medicines for treatment of ADHD in clinical studies covering approximately 7000 children, the majority of 6- to 12-year-old boys, and particularly in the United States of America (USA). The most frequently reported ADRs were decrease in appetite, gastrointestinal pain, and headache. There were wide variations in reported ADR occurrence between studies of similar design, setting, included population, and type of medication. Reported ADRs were primarily assessed by the children/their parents, and very few ADRs were rated as being serious. A large number of children dropped out of studies due to serious ADRs, and therefore, the actual number of serious ADRs from use of psychostimulants is probably higher. A large number of studies were conducted by the same groups of authors and sponsored by the pharmaceutical companies manufacturing the respective medications.

CONCLUSION

Reported ADRs from use of psychostimulants in children were found in clinical trials of short duration. Since ADHD medications are prescribed for long-term treatment, there is a need for long-term safety studies. The pharmaceutical companies should make all information about ADRs reported for these medications accessible to the public, and further studies are needed on the impact of the link between researchers and the manufacturers of the respective products.

The effects of chronic methylphenidate administration on operant test battery performance in juvenile rhesus monkeys

Methylphenidate (MPH) is an amphetamine derivative widely prescribed for the treatment of attention deficit-hyperactivity disorder. Recent concern over its genotoxic potential in children [11] spurred a study on the effects of chronic MPH treatment in a nonhuman primate population and the studies reported here were conducted in conjunction with that study in the same animals. Here, the focus was on the ability of juvenile rhesus monkeys to learn how to perform a battery of operant behavioral tasks while being treated chronically with MPH. Performance of the National Center for Toxicological Research (NCTR) Operant Test Battery (OTB) was used to quantify the learning of tasks thought to model specific aspects of cognitive function including learning, motivation, color and position discrimination, and short-term memory. The OTB tasks designed to assess these specific behaviors included Incremental Repeated Acquisition (IRA), Progressive Ratio (PR), Conditioned Position Responding (CPR), and Delayed Matching-to-Sample (DMTS), respectively. Juvenile males (n=10/group) pressed levers and press-plates for banana-flavored food pellets. Subjects were treated orally, twice a day, five days per week (M-F) for 66 weeks with escalating doses (0.15 mg/kg initially, increased to 2.5 mg/kg for the low dose group and to 12.5 mg/kg for the high dose group) and tested in OTB tasks 30 to 60 min after the morning dose. The findings indicate that MPH at doses up to 2.5 mg/kg twice per day were well tolerated (performance was no different than controls) but at doses of 12.5 mg/kg twice per day there was a significant decrement in OTB performance, characterized by decreases in both percent task completed and response rates for all tasks. These effects of MPH seem primarily due to decreases in motivation to perform for food, which is not surprising given the well known appetite suppressing effects of amphetamine-like stimulants. Thus, the current data do not strongly suggest cognitive impairments following chronic MPH administration.

Safety of stimulant treatment in attention deficit hyperactivity disorder: Part I

BACKGROUND

The safety profile of newer stimulant products is of interest. Because most studies focus on school-age children, there is also an increased interest in the treatment of other populations. Concern continues for the risk of substance abuse in the use of stimulants.

OBJECTIVE

The purpose of this paper is to review published data on the safety and tolerability of the newer forms of stimulants, treatment in special populations, and the risks of substance abuse and dependence in the treatment of attention deficit hyperactivity disorder.

METHODS

Literature obtained through Medline and Pubmed from 1995 were reviewed as well as key articles referenced in the literature.

CONCLUSIONS

The use of the newer stimulant agents shows a safety profile of frequent, but usually mild side effects. They are generally safe in special populations. The risk of developing long-term substance abuse with attention deficit hyperactivity disorder, without co-morbidities, is small and may decrease with proper treatment. More research is needed.

DIFFERENTIAL LOCOMOTOR RESPONSES IN MALE RATS FROM THREE STRAINS TO ACUTE METHYLPHENIDATE

Genetic variability is an important consideration in the study of the effect of drugs on humans and animals. Specifically, the effect of drugs on behavior varies from one rat strain to another. Methylphenidate (MPI), commonly known as Ritalin, is a psychostimulant with a pharmacological profile similar to amphetamine and cocaine, and is widely used in the treatment of attention deficit/hyperactivity disorder (ADHD). The purpose of this study was to examine the acute dose-response characteristics of MPD on three different male rat strains: spontaneously hypertensive/hyperactive rats (SHR), Wistar-Kyoto (WKY) rats, and Sprague-Dawley (SD) rats. Results showed clear differences in the pattern of behavioral response to the various MPD doses among the three rat strains. The 0.6 mg/kg MPD dose had no effect on any of the strains. At the dose of 2.5 mg/kg MPD, WKY rats reached peak locomotor activity within the initial 10 min, whereas SHR and SD rats reached peak activity in approximately 30 min. Furthermore, the effects on locomotor activity of SHR were longer in duration and higher in locomotor activity, whereas the effects on SD rats were shorter in duration and amplitude. Following the 10.0 mg/kg MPD, WKY, and SD mats reached their peak locomotor activity within 80 min post-injection, whereas SHR reached their peak locomotor activity within the initial 10 min post-injection. In addition, the SHR strain exhibited increased behavioral sensitivity to MPD as expressed by the latency, duration, and amplitude of their response. In conclusion, the dose-response experiment on the acute effects of MPD demonstrated that there are genetic differences in the responses to MPD.

Psychopharmacology and preschoolers: a critical review of current conditions

Rates of prescriptions for very young children have increased notably in the last 20 years. These changes have occurred in the context of increasing attention to early childhood mental health, availability of medications perceived to be safer than older medications, application of the medical model to the mental health care of young children, as well as other cultural shifts. Psychopharmacological treatment for any patient, but especially very young children, requires consideration of central nervous system (CNS) and metabolic development and issues of diagnostic validity and should be guided by an empirical literature. In young children, this literature is quite limited. In this article, the authors review developmental issues involved in psychopharmacological treatment and present existing literature and practical guidelines for common preschool diagnoses, recognizing that for some disorders, the extant literature does not support even consideration of medications.

Review of pediatric attention deficit/hyperactivity disorder for the general psychiatrist

Attention deficit/hyperactivity disorder (ADHD) is a common and impairing psychiatric condition, affecting significant numbers of children and adolescents. General psychiatrists serve, both by choice and out of necessity, in the assessment and treatment of children and adolescents who have ADHD and in the education of patients and their families. For many clinicians, however, there are numerous unanswered questions regarding the diagnosis and therapeutic interventions for ADHD. This article provides general psychiatrists with a practical overview and update on the assessment, diagnosis, and treatment of pediatric ADHD. Background information, recent relevant research, current evidence-based practice guidelines, and tips for clinical practice are reviewed in this article. The information is presented in a question-answer format.

Psychopharmacological and other treatments in preschool children with attention-deficit/hyperactivity disorder: current evidence and practice

OBJECTIVE

This article reviews rational approaches to treating attention-deficit/hyperactivity disorder (ADHD) in preschool children, including pharmacological and nonpharmacological treatments. Implications for clinical practice are discussed.

DATA SOURCES

We searched MEDLINE, PsychINFO, Cumulative Index to Nursing & Allied Health, Educational Resources Information Center, Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effects for relevant literature published in English from 1967 to 2007 on preschool ADHD. We also reviewed the references cited in identified reports.

STUDY SELECTION

Studies were reviewed if the sample included at least some children younger than 6 years of age or attending kindergarten, the study participants had a diagnosis of ADHD or equivalent symptoms, received intervention aimed at ADHD symptoms, and included a relevant outcome measure.

DATA EXTRACTION

Studies were reviewed for type of intervention and outcome relevant to ADHD and were rated for the level of evidence for adequacy of the data to inform clinical practice.

CONCLUSIONS

The current level of evidence for adequacy of empirical data to inform clinical practice for short-term treatment of ADHD in preschool children is Level A for methylphenidate and Level B for parent behavior training, child training, and additive-free elimination diet.

Unexpected effects of methylphenidate in attention-deficit/hyperactivity disorder reflect decreases in core/secondary symptoms and physical complaints common to all children

Abstract Hypotheses concerning unexpected, psychostimulant-related effects reported in previous studies were examined by separating behavioral/physical complaints highly specific to methylphenidate (MPH) from those that (a) may mimic core/secondary symptoms of the disorder, or (b) are commonly reported by unmedicated children in the general population. Sixty-five children with attention-deficit/hyperactivity disorder (ADHD) participated in a double-blind, placebo-controlled, within-subject (crossover) experimental design and received a placebo and four MPH doses in counterbalanced order following baseline assessment. Behavioral and physical complaints were significantly higher under baseline relative to placebo and the four immediate-release MPH conditions (5 mg, 10 mg, 15 mg, and 20 mg) across three symptom categories: ADHD core/secondary symptoms; symptoms commonly reported in the general population, including unmedicated children with ADHD; and symptoms highly specific to MPH. No significant differences were found among active drug conditions. Past unexpected findings of psychostimulant effects in ADHD may be due to the inclusion of scale items that reflect core/secondary features of ADHD and normally occurring behavioral/physical complaints in children.

Attention deficit hyperactivity disorder in preschool children

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with a childhood onset of symptoms and impairment. Although it is most frequently identified during elementary school years, epidemiologic data suggest that the onset of ADHD frequently occurs earlier, with presentation as young as 3 years of age. Early identification, however, allows consideration of appropriate interventions. Many data are available on safe and efficacious treatment options for school-aged children who have ADHD; however, little is known about the use of these modalities in preschoolers and, ultimately, the long-term effects of early treatment. Recognition of the preschool presentation of ADHD, appropriate differential diagnosis, and identification of comorbid conditions, and a developmental perspective on the course and potential outcomes of the disorder may guide treatment planning. Newly available data on the safety and efficacy of pharmacotherapy and psychosocial intervention for preschoolers who have ADHD may help clinicians make treatment decisions for these young children and their families.

Beyond the 'typical' patient: treating attention-deficit/hyperactivity disorder in preschoolers and adults

Attention-deficit/hyperactivity disorder (ADHD), typically affects school-aged children, but can present during the preschool years and persist into adulthood. Accurate diagnosis for preschoolers and adults requires adaptation of the current diagnostic criteria to account for differences in symptomatology across the age span. The differential diagnosis of ADHD and the pattern of psychiatric comorbidity vary with each age group and complicate diagnosis and management. To maximize outcomes clinicians must be able to accurately identify ADHD across the lifespan, and develop comprehensive, collaborative treatment plans. The Preschool ADHD Treatment Study (PATS) demonstrated the potential utility of methylphenidate for treating ADHD in preschoolers, and trials of psychostimulants and atomoxetine have shown some benefits for adults. Behavioural interventions likely have an adjunctive role in ADHD treatment for both groups. More research, however, is needed to determine the safest and most effective pharmacotherapies and psychosocial interventions for these non-typical patients.

Effectiveness of methylphenidate in the 10-month continuation phase of the Preschoolers with Attention-Deficit/Hyperactivity Disorder Treatment Study (PATS)

OBJECTIVE

The aim of this study was to examine immediate-release methylphenidate effectiveness during the 10-month open-label continuation phase of the Preschoolers with Attention-Deficit/Hyperactivity Disorder (ADHD) Treatment Study (PATS).

METHODS

One hundred and forty preschoolers with ADHD, who had improved with acute immediate-release methylphenidate (IR-MPH) treatment, entered a 10-month, open-label medication maintenance at six sites. Assessments included the Clinical Global Impression-Severity (CGI-S), CGI-Improvement (CGI-I), Children's Global Assessment Scale (C-GAS), Swanson, Nolan, and Pelham Questionnaire (SNAP), Scale Strengths and Weaknesses of ADHD-Symptoms and Normal Behaviors (SWAN), Social Competence Scale, Social Skills Rating System (SSRS), and Parenting Stress Index-Short Form (PSI-SF).

RESULTS

For the 95 children who completed the 10-month treatment, improvement occurred on the CGI-S (p = 0.02), CGI-I (p < 0.01), C-GAS (p = 0.001), and SSRS (p = 0.01). SNAP and SWAN scores remained stable. Forty five children discontinued: 7 for adverse effects, 7 for behavior worsening, 7 for switching to long-acting stimulants, 3 for inadequate benefit, and 21 for other reasons. The mean MPH dose increased from 14.04 mg/day +/- SD 7.57 (0.71 +/- 0.38 mg/kg per day) at month 1 to 19.98 mg/day +/- 9.56 (0.92 +/- 0.40 mg/kg per day) at month 10.

CONCLUSIONS

With careful monitoring and gradual medication dose increase, most preschoolers with ADHD maintained improvement during long-term IR-MPH treatment. There was substantial variability in effective and tolerated dosing.

A pilot study of atomoxetine in young children with attention-deficit/hyperactivity disorder

OBJECTIVE

The purpose of this study was to assess the effectiveness and tolerability of atomoxetine during acute treatment of attention-deficit/hyperactivity disorder (ADHD) in 5 and 6 year olds.

METHOD

Twenty two children (male n = 19, 86%) with ADHD were treated with atomoxetine for 8 weeks in a three-site, open-label pilot study. Dosing was flexible, with titration to a maximum of 1.8 mg/kg per day. Parent education on behavior management was provided as part of each pharmacotherapy visit.

RESULTS

Subjects demonstrated a mean decrease of 20.68 points (SD = 12.80, p < 0.001)) on the ADHD Rating Scale-IV (ADHD-IV-RS) total score, 10.18 (SD = 7.48, p < 0.001) on the inattentive subscale and 10.50 (SD = 7.04, p < 0.001) on the hyperactive/impulsive subscale. Clinical Global Impression-Severity (CGI-S) was improved in 82% of the children (95% CI, 66-98%) and Children's Global Assessment (CGAS) scores improved 18.91 points on average (SD = 12.20, p < 0.001). The mean final dose of atomoxetine was 1.25 mg/kg per day (SD = 0.35 mg/kg per day). Mood lability was the most commonly reported adverse event (n = 12, 54.5%). Eleven subjects (50%) reported decreased appetite and a mean weight loss of 1.04 kg (SD = 0.80 kg) (p < 0.001) was observed for the group. Vital sign changes were mild and not clinically significant. There were no discontinuations due to adverse events or lack of efficacy.

CONCLUSION

Atomoxetine was generally effective for reducing core ADHD symptoms in the 5 and 6 year olds in this open-label study.

Rationale, design, and methods of the Preschool ADHD Treatment Study (PATS)

OBJECTIVE

To describe the rationale and design of the Preschool ADHD Treatment Study (PATS).

METHOD

PATS was a National Institutes of Mental Health-funded, multicenter, randomized, efficacy trial designed to evaluate the short-term (5 weeks) efficacy and long-term (40 weeks) safety of methylphenidate (MPH) in preschoolers with attention-deficit/hyperactivity disorder (ADHD). Three hundred three subjects ages 3 to 5.5 years old who met criteria for a primary DSM-IV diagnosis of ADHD entered the trial. Subjects participated in an 8-phase, 70-week trial that included screening, parent training, baseline, open-label safety lead-in, double-blind crossover titration, double-blind parallel efficacy, open-label maintenance, and double-blind discontinuation. Medication response was assessed during the crossover titration phase using a combination of parent and teacher ratings. Special ethical considerations throughout the trial warranted a number of design changes.

RESULTS

This report describes the design of this trial, the rationale for reevaluation and modification of the design, and the methods used to conduct the trial.

CONCLUSIONS

The PATS adds to a limited literature and improves our understanding of the safety and efficacy of MPH in the treatment of preschoolers with ADHD, but changes in the design and problems in implementation of this study impose some specific limitations that need to be addressed in future studies.

Safety and tolerability of methylphenidate in preschool children with ADHD

OBJECTIVE

To report on the safety and tolerability of methylphenidate (MPH) 3- to 5-year-old children with attention-deficit/hyperactivity disorder (ADHD) during 1 year of treatment.

METHOD

Exactly 183 children (3-5 years old) entered a treatment study of MPH, consisting of a 1-week open-label lead-in (n=183); a 5-week placebo-controlled, double-blind phase (n=165); a 5-week double-blind, parallel phase (n=114); and 10 months of open-label maintenance (n=140 entered, 95 completed). Mean total daily MPH doses rose from the titration trial best dose, 14.1 (+/-8.1) mg/day, to 20.5 (+/-9.7) mg/day mean total daily dose at the end of maintenance. Pulse, blood pressure, and the presence of treatment emergent adverse events (AEs), parent and teacher AE ratings, and vital signs were recorded in each phase.

RESULTS

Thirty percent of parents spontaneously reported moderate to severe AEs in all study phases after baseline. These included emotional outbursts, difficulty falling asleep, repetitive behaviors/thoughts, appetite decrease, and irritability. During titration, decreased appetite (chi=5.4, p<.03), trouble sleeping (chi=5.4, p<.03), and weight loss (chi=4.0, p<.05) occurred statistically more often on MPH than on placebo. During maintenance, trouble sleeping and appetite loss persisted and other MPH-related AEs decreased. There were transient, one-time pulse and blood pressure elevations in five children. Twenty-one children (11%) discontinued because of drug-attributed AEs.

CONCLUSIONS

Eleven percent of preschoolers discontinued treatment because of intolerable MPH AEs. Of the serious AEs reported, one occurred in baseline, two in lead-in, three in titration, one in parallel, and one in maintenance. Only one was possibly related to MPH.

Efficacy and safety of immediate-release methylphenidate treatment for preschoolers with ADHD

OBJECTIVE

The Preschool ADHD Treatment Study (PATS) was a NIMH-funded, six-center, randomized, controlled trial to determine the efficacy and safety of immediate-release methylphenidate (MPH-IR), given t.i.d. to children ages 3 to 5.5 years with attention-deficit/hyperactivity disorder (ADHD).

METHOD

The 8-phase, 70-week PATS protocol included two double-blind, controlled phases, a crossover-titration trial followed by a placebo-controlled parallel trial. The crossover-titration phase's primary efficacy measure was a combined score from the Swanson, Kotkin, Atkins, M-Flynn, and Pelham (SKAMP) plus the Conners, Loney, and Milich (CLAM) rating scales; the parallel phase's primary outcome measure was excellent response, based on composite scores on the Swanson, Nolan, and Pelham (SNAP) rating scale.

RESULTS

Of 303 preschoolers enrolled, 165 were randomized into the titration trial. Compared with placebo, significant decreases in ADHD symptoms were found on MPH at 2.5 mg (p<.01), 5 mg (p<.001), and 7.5 mg (p<.001) t.i.d. doses, but not for 1.25 mg (p<.06). The mean optimal MPH total daily dose for the entire group was 14.2 +/- 8.1 mg/day (0.7+/-0.4 mg/kg/day). For the preschoolers (n=114) later randomized into the parallel phase, only 21% on best-dose MPH and 13% on placebo achieved MTA-defined categorical criterion for remission set for school-age children with ADHD.

CONCLUSIONS

MPH-IR, delivered in 2.5-, 5-, and 7.5-mg doses t.i.d., produced significant reductions on ADHD symptom scales in preschoolers compared to placebo, although effect sizes (0.4-0.8) were smaller than those cited for school-age children on the same medication.

What is attention-deficit hyperactivity disorder (ADHD)?

Attention-deficit hyperactivity disorder (ADHD) is described as the most common neurobehavioral condition of childhood. We raise the concern that ADHD is not a disease per se but rather a group of symptoms representing a final common behavioral pathway for a gamut of emotional, psychological, and/or learning problems. Increasing numbers of children, especially boys, are diagnosed with ADHD and treated with stimulant medications according to a simplified approach. Methodical review of the literature, however, raised concerning issues. "Core" ADHD symptoms of inattentiveness, hyperactivity and impulsivity are not unique to ADHD. Rates of "comorbid" psychiatric and learning problems, including depression and anxiety, range from 12 to 60%, with significant symptom overlap with ADHD, difficulties in diagnosis, and evidence-based treatment methods that do not include stimulant medications. No neuropsychologic test result is pathognomic for ADHD, and structural and functional neuroimaging studies have not identified a unique etiology for ADHD. No genetic marker has been consistently identified, and heritability studies are confounded by familial environmental factors. The validity of the Conners' Rating Scale-Revised has been seriously questioned, and parent and teacher "ratings" of school children are frequently discrepant, suggesting that use of subjective informant data via scale or interview does not form an objective basis for diagnosis of ADHD. Empiric diagnostic trials of stimulant medication that produce a behavioral response have been shown not to distinguish between children with and without "ADHD." In summary, the working dogma that ADHD is a disease or neurobehavioral condition does not at this time hold up to scrutiny of evidence. Thorough evaluation of symptomatic children should be individualized, and include assessment of educational, psychologic, psychiatric, and family needs.

Stimulant medication effects in a summer treatment program among young children with attention-deficit/hyperactivity disorder

OBJECTIVE

This study examined the effectiveness of stimulant medication on multiple domains of functioning in 36 young (5 to 6 years old) children diagnosed with attention-deficit/hyperactivity disorder (ADHD).

METHOD

Five- and 6-year-old children attending a summer treatment program between 1987 and 1997 underwent a randomized clinical assessment of the effect of two doses of methylphenidate (0.3 mg/kg versus 0.6 mg/kg) and placebo on social behavior and academic performance.

RESULTS

Methylphenidate had an effect on all four social behaviors and improved two of the three areas of academic functioning. Dose effects were present for three of the seven dependent measures. Individual analyses indicated a therapeutic response rate between 39% and 100% across dependent measures. Furthermore, individual analyses of response indicated that across several important dependent measures, 39% to 98% of children showed little incremental improvement with the higher dose compared with the lower dose of stimulant medication.

CONCLUSIONS

Stimulant medication is an effective treatment for young children diagnosed with ADHD; however, multiple domains of functioning must be assessed to determine the most effective dose for young children with ADHD.

The role of stimulants in the treatment of preschool children with attention-deficit hyperactivity disorder

The symptoms of attention-deficit hyperactivity disorder (ADHD) can have an early onset, beginning before the age of 6 years. Despite the significant number of preschool-aged children that can be diagnosed with ADHD, there are limited controlled data available on the pharmacological interventions being increasingly used in this population. A 1990 review showed that 34% of paediatricians and 15% of family physicians had prescribed psychostimulant medications to preschoolers with ADHD, and pharmacoepidemiological studies indicate growing use of stimulants in preschoolers during the 1990s. Unfortunately, only six controlled trials, with a total enrollment of less than 200 children, have been conducted using these drugs in preschoolers. While these small studies provide some evidence of benefit from the use of methylphenidate in preschoolers with ADHD, more data are critically needed. Practice parameters developed by the American Academy of Child & Adolescent Psychiatry and the American Academy of Pediatrics provide some guidance regarding the diagnosis and treatment of young children with ADHD, but are mainly based upon research in children of primary-school age. The ongoing PATS (Preschool ADHD Treatment Study), funded by the National Institute of Mental Health, will provide important clinical guidance for diagnostic considerations and intervention strategies for children with ADHD aged 3-5 years. Pending the release of data from the PATS study, clinicians must rely on developmental assessment skills, available standardised rating instruments, reports about the child from multiple informants, and knowledge of the risks and benefits of available pharmacological and behavioural treatments, in order to treat preschool children with ADHD effectively.

A prospective study of stimulant response in preschool children: insights from ROC analyses

OBJECTIVE

The purpose of this study was to examine the efficacy of psychostimulant medication in a naturalistic sample of preschoolers. Benefits and side effects for methylphenidate and mixed amphetamine salts (Adderall) were examined.

METHOD

Twenty-eight preschoolers (ages 4.0 - 5.9) participated in the present investigation. They were obtained consecutively from a large sample of suburban children assessed for attention-deficit/hyperactivity disorder. After having received various dosing levels of a stimulant in a placebo-controlled crossover design, best dose was assigned based on the lowest Abbreviated Symptoms Questionnaire T score received in a given week. All analyses compared best dose ratings to placebo ratings.

RESULTS

Preschoolers' behavioral ratings by parents and teachers were improved as a function of stimulant medication. More than 82% of the medicated sample improved their behavioral rating by at least 1 SD as demonstrated by receiver operating characteristic (ROC) analyses, with more than 50% of medicated preschoolers improving by more than 2 SD. Side effects were infrequent at best dose of medication.

CONCLUSIONS

Clinically significant changes in behavioral ratings of preschoolers were noted in response to stimulant medication. Both stimulants were well tolerated. ROC curves were useful for clearly depicting on a case-by-case basis how much improvement was derived from psychopharmacological treatment.

Psychopathology and substance abuse in parents of young children with attention-deficit/hyperactivity disorder

OBJECTIVE

To compare the prevalence of psychological disorders in parents of young children with and without attention-deficit/hyperactivity disorder (ADHD) and comorbid disruptive behavior disorders (DBD).

METHOD

Subjects included 98 three- to seven-year-old children with DSM-IV ADHD (68 with ADHD and comorbid oppositional defiant or conduct disorder [ADHD+ODD/CD]) and 116 non-ADHD comparison children recruited in 1995-96 during the first wave of a longitudinal study. Biological mothers were administered interviews to assess ADHD and DBD in their children and mood, anxiety, and substance use disorders in themselves. In addition, they were queried about symptoms of childhood ADHD and DBD, and antisocial personality disorder in themselves and their children's biological fathers.

RESULTS

Child ADHD was associated with increased rates of maternal and paternal childhood ADHD relative to comparison children. Child ADHD+ODD/CD was associated with maternal mood disorders, anxiety disorders, and stimulant/cocaine dependence, and paternal childhood DBD. Mothers of children with ADHD+ODD/CD also reported increased drinking problems in their children's fathers.

CONCLUSIONS

These findings indicate that many young children with ADHD, particularly those with comorbid ODD/CD, require comprehensive services to address both their ADHD and the mental health needs of their parents.

Response to methylphenidate in children with attention deficit hyperactivity disorder and manic symptoms in the multimodal treatment study of children with attention deficit hyperactivity disorder titration trial

OBJECTIVE

Recent reports raise concern that children with attention deficit hyperactivity disorder (ADHD) and some manic symptoms may worsen with stimulant treatment. This study examines the response to methylphenidate in such children.

METHODS

Data from children participating in the 1-month methylphenidate titration trial of the Multimodal Treatment Study of Children with ADHD were reanalyzed by dividing the sample into children with and without some manic symptoms. Two "mania proxies" were constructed using items from the Diagnostic Interview Schedule for Children (DISC) or the Child Behavior Checklist (CBCL). Treatment response and side effects are compared between participants with and without proxies.

RESULTS

Thirty-two (11%) and 29 (10%) participants fulfilled criteria for the CBCL mania proxy and DISC mania proxy, respectively. Presence or absence of either proxy did not predict a greater or lesser response or side effects.

CONCLUSION

Findings suggest that children with ADHD and manic symptoms respond robustly to methylphenidate during the first month of treatment and that these children are not more likely to have an adverse response to methylphenidate. Further research is needed to explore how such children will respond during long-term treatment. Clinicians should not a priori avoid stimulants in children with ADHD and some manic symptoms.

Patterns of psychotropic medication use in very young children with attention-deficit hyperactivity disorder

Psychotropic medications are increasingly used for very young children. Patterns of use in a well-described group of children 3 years and younger with a diagnostic label of attention-deficit hyperactivity disorder (ADHD) reveal both reasons to use such medications and concerns about how these medications are used. Of 223 children with ADHD, more than half (n = 127) received psychotropic medications in an idiosyncratic manner, both in the specific medication and in use over time. Almost half of the children who were medicated did not have opportunities for monitoring as often as every 3 months, despite the fact that more than half received psychotropic medications for 6 months or longer. Children with comorbid mental health conditions and chronic health conditions were at greater risk for receiving psychotropic medications. These patterns of use demonstrate a compelling need for guidance in psychopharmacological treatment of very young children.

Practice parameter for the use of stimulant medications in the treatment of children, adolescents, and adults

This practice parameter describes treatment with stimulant medication. It uses an evidence-based medicine approach derived from a detailed literature review and expert consultation. Stimulant medications in clinical use include methylphenidate, dextroamphetamine, mixed-salts amphetamine, and pemoline. It carries FDA indications for treatment of attention-deficit/hyperactivity disorder and narcolepsy.