ADHD in girls: clinical comparability of a research sample

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 In addition, we checked reference lists and requested published and unpublished data from manufacturers of methylphenidate.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

Effectiveness and safety of dexamphetamine sulfate (Attentin®) in the routine treatment of children and adolescents with ADHD: results from a 12-month non-interventional study

Background

Randomized controlled trials have shown that dexamphetamine sulfate (DEX) is efficacious in the treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents; however, data on the effectiveness and safety of DEX in routine practice are scarce.

Objective

This study investigated the long-term effectiveness and safety of Attentin^® (immediate-release DEX) in children and adolescents with ADHD in routine practice.

Methods

ATTENTION was a multicenter, prospective, observational, non-interventional study that enrolled pediatric patients with ADHD (aged 6-17 years) with a clinically inadequate response to previous methylphenidate (MPH) treatment. Patients were assessed at baseline and two follow-up visits after approx. 6 and 12 months of DEX treatment. The primary endpoint was the investigator-rated ADHD rating scale IV (ADHD-RS-IV) total score change from baseline to the first follow-up visit.

Results

The study enrolled 140 patients (mean age: 11.2 years). Significant reductions in ADHD-RS-IV total scores were observed in the titration phase and were maintained up to the second follow-up visit. The mean ADHD-RS-IV total score change from baseline to the first follow-up visit was -11.9 (27.1 vs. 13.4, p < .001). Beneficial effects of DEX were observed on both ADHD-RS-IV subscales ('hyperactivity/impulsivity' and 'inattention') and in both children and adolescents. Clinical response, defined as a reduction in the ADHD-RS-IV total score of at least 30% at the first follow-up visit, was observed in 78.1% of patients. Patients reported an average onset of action of 36.2 minutes and an average duration of action of 6.5 hours after intake of the first dose of DEX in the morning. DEX was well tolerated. Small significant increases in mean systolic and diastolic blood pressure compared to baseline were observed.

Conclusions

Attentin^® is an effective and well-tolerated long-term treatment for pediatric ADHD patients with a clinically inadequate response to previous MPH treatment.

Cardiovascular Risk of Concomitant Use of Atypical Antipsychotics and Stimulants Among Commercially Insured Youth in the United States

Objectives: To investigate the risk of cardiovascular events associated with concomitant use of stimulants and atypical antipsychotics (AAPs) among youth and evaluate whether AAP dose and duration of concomitant use modifies the risk. Methods: We used IQVIA PharMetrics® Plus data from 2006 to 2015 to construct a retrospective cohort of commercially-insured youth aged 5-17 years old who initiated a stimulant medication. Time-varying concomitant stimulant/AAP use was defined as current, past and no concomitant use based on person months. The primary time-varying Cox proportional hazard regression analysis evaluated the risk of cardiovascular events comparing current concomitant use with past and no concomitant use, adjusted for baseline cardiovascular risk. A secondary analysis assessed the risk of cardiovascular events comparing AAP daily doses (<1, 1-2, >2 mg) and duration (<3, 3-6, >6 months) of current concomitant use to no concomitant use. Cardiovascular outcomes included severe (i.e., stroke, acute myocardial infarction, ischemic heart disease) and less severe (i.e., angina pectoris, cardiac dysrhythmias, transient cerebral ischemia, hypertensive disease, tachycardia, palpitations, syncope). Results: For this cohort of 61,438 youths, the incidence rate of severe cardiovascular events was 0.18 per 10,000 person-months, and all events occurred in no concomitant use months. The risk of less severe cardiovascular events was significantly higher in current concomitant users compared with no [HR: 2.59 (95%CI: 1.72, 3.90)] and past [HR: 1.89 (95%CI: 1.10, 3.24)] concomitant users. Compared to no concomitant use, the risk of less severe cardiovascular events was significantly higher at all AAP daily doses [HR: <1 mg: 2.82 (95%CI: 1.72, 4.61); 1-2 mg: 2.22 (95%CI: 1.16, 4.25); >2 mg: 2.65 (95%CI: 1.50, 4.71)]. The risk of less severe cardiovascular events significantly elevated for all duration of use and was higher for <3 months of concomitant use [HR: <3 months: 3.45 (95%CI: 2.17, 5.47) relative to 3-6 months: 2.60 (95%CI: 1.29, 5.25) or >6 months: 2.61 (95%CI: 1.59, 4.30)]. Conclusions: Severe cardiovascular events are rare. Concomitant stimulant/AAP use elevates the risk of less severe cardiovascular events. Periodic heart rate or blood pressure monitoring for youth on stimulant/AAP treatment may be warranted.

Sex Differences in the Meaning of Parent and Teacher Ratings of ADHD Behaviors: An Observational Study

Objective: To test explanations for the underrecognition of female ADHD by examining differences in adult ratings of boys and girls matched for levels of directly observed ADHD behaviors. Method: In a secondary analysis of a population-based sample, 3- to 4-year-olds (n = 153, 79 male) and 8- to 9-year-olds (n = 144, 75 male) were grouped according to levels of directly observed ADHD behaviors (low/moderate/high). Groups were then compared with parent/teacher ADHD ratings. Results: There were no sex differences in levels of directly observed ADHD behaviors within groups. For preschoolers, parents' ratings of males, but not females, significantly increased across groups-mirroring levels of observed behaviors. For older children, both parent and teacher mean ratings were significantly higher for males than females across groups. Conclusion: Identified differences in adult ratings of males and females matched for directly observed behaviors may contribute to understanding the substantial ADHD underrecognition in females.

Females with ADHD: An expert consensus statement taking a lifespan approach providing guidance for the identification and treatment of attention-deficit/ hyperactivity disorder in girls and women

BACKGROUND

There is evidence to suggest that the broad discrepancy in the ratio of males to females with diagnosed ADHD is due, at least in part, to lack of recognition and/or referral bias in females. Studies suggest that females with ADHD present with differences in their profile of symptoms, comorbidity and associated functioning compared with males. This consensus aims to provide a better understanding of females with ADHD in order to improve recognition and referral. Comprehensive assessment and appropriate treatment is hoped to enhance longer-term clinical outcomes and patient wellbeing for females with ADHD.

METHODS

The United Kingdom ADHD Partnership hosted a meeting of experts to discuss symptom presentation, triggers for referral, assessment, treatment and multi-agency liaison for females with ADHD across the lifespan.

RESULTS

A consensus was reached offering practical guidance to support medical and mental health practitioners working with females with ADHD. The potential challenges of working with this patient group were identified, as well as specific barriers that may hinder recognition. These included symptomatic differences, gender biases, comorbidities and the compensatory strategies that may mask or overshadow underlying symptoms of ADHD. Furthermore, we determined the broader needs of these patients and considered how multi-agency liaison may provide the support to meet them.

CONCLUSIONS

This practical approach based upon expert consensus will inform effective identification, treatment and support of girls and women with ADHD. It is important to move away from the prevalent perspective that ADHD is a behavioural disorder and attend to the more subtle and/or internalised presentation that is common in females. It is essential to adopt a lifespan model of care to support the complex transitions experienced by females that occur in parallel to change in clinical presentation and social circumstances. Treatment with pharmacological and psychological interventions is expected to have a positive impact leading to increased productivity, decreased resource utilization and most importantly, improved long-term outcomes for girls and women.

Quasi-periodic patterns of brain activity in individuals with attention-deficit/hyperactivity disorder

Individuals with attention-deficit/hyperactivity disorder have disrupted functional connectivity in the default mode and task positive networks. Traditional fMRI analysis techniques that focus on 'static' changes in functional connectivity have been successful in identifying differences between healthy controls and individuals with ADHD. However, such analyses are unable to explain the mechanisms behind the functional connectivity differences observed. Here, we study dynamic changes in functional connectivity in individuals with ADHD through investigation of quasi-periodic patterns (QPPs). QPPs are reliably recurring low-frequency spatiotemporal patterns in the brain linked to infra-slow electrical activity. They have been shown to contribute to functional connectivity observed through static analysis techniques. We find that QPPs contribute to functional connectivity specifically in regions that are disrupted in individuals with ADHD. Individuals with ADHD also show differences in the spatiotemporal pattern observed within the QPPs. This difference results in a weaker contribution of QPPs to functional connectivity in the default mode and task positive networks. We conclude that quasi-periodic patterns provide insight into the mechanisms behind functional connectivity differences seen in individuals with ADHD. This allows for a better understanding of the etiology of the disorder and development of effective treatments.

Sex differences in predicting ADHD clinical diagnosis and pharmacological treatment

In youth, ADHD is more commonly diagnosed in males than females, but higher male-to-female ratios are found in clinical versus population-based samples, suggesting a sex bias in the process of receiving a clinical diagnosis of ADHD. This study investigated sex differences in the severity and presentation of ADHD symptoms, conduct problems, and learning problems in males and females with and without clinically diagnosed ADHD. We then investigated whether the predictive associations of these symptom domains on being diagnosed and treated for ADHD differed in males and females. Parents of 19,804 twins (50.64% male) from the Swedish population completed dimensional assessments of ADHD symptoms and co-occurring traits (conduct and learning problems) when children were aged 9 years. Children from this population sample were linked to Patient Register data on clinical ADHD diagnosis and medication prescriptions. At the population level, males had higher scores for all symptom domains (inattention, hyperactivity/impulsivity, conduct, and learning problems) compared to females, but similar severity was seen in clinically diagnosed males and females. Symptom severity for all domains increased the likelihood of receiving an ADHD diagnosis in both males and females. Prediction analyses revealed significant sex-by-symptom interactions on diagnostic and treatment status for hyperactivity/impulsivity and conduct problems. In females, these behaviours were stronger predictors of clinical diagnosis (hyperactivity/impulsivity: OR 1.08, 95% CI 1.01, 1.15; conduct: OR 1.43, 95% CI 1.09, 1.87), and prescription of pharmacological treatment (hyperactivity/impulsivity: OR 1.24, 95% CI 1.02, 1.50; conduct: OR 2.20, 95% CI 1.05, 4.63). Females with ADHD may be more easily missed in the ADHD diagnostic process and less likely to be prescribed medication unless they have prominent externalising problems.

Premature responding is associated with approach to a food cue in male and female heterogeneous stock rats

RATIONALE

Disorders of behavioral regulation, including attention deficit hyperactivity disorder (ADHD) and drug addiction, are in part due to poor inhibitory control, attentional deficits, and hyper-responsivity to reward-associated cues.

OBJECTIVES

To determine whether these traits are related, we tested genetically variable male and female heterogeneous stock rats in the choice reaction time (CRT) task and Pavlovian conditioned approach (PavCA). Sex differences in the response to methylphenidate during the CRT were also assessed.

METHODS

In the CRT task, rats were required to withhold responding until one of two lights indicated whether responses into a left or right port would be reinforced with water. Reaction time on correct trials and premature responses were the operational definitions of attention and response inhibition, respectively. Rats were also pretreated with oral methylphenidate (0, 2, 4 mg/kg) during the CRT task to determine whether this drug would improve performance. Subsequently, during PavCA, presentation of an illuminated lever predicted the delivery of a food pellet into a food-cup. Lever-directed approach (sign-tracking) and food-cup approach (goal-tracking) were the primary measures, and rats were categorized as "sign-trackers" and "goal-trackers" using an index based on these measures.

RESULTS

Sign-trackers made more premature responses than goal-trackers but showed no differences in reaction time. There were sex differences in both tasks, with females having higher sign-tracking, completing more CRT trials, and making more premature responses after methylphenidate administration.

CONCLUSIONS

These results indicate that response inhibition is related to reward-cue responsivity, suggesting that these traits are influenced by common genetic factors.

ADHD symptoms and peer relations of children in a community sample: Examining associated problems, self-perceptions, and gender differences

This study examined children's peer relations in relation to gender, symptoms of attention-deficit/ hyperactivity disorder (ADHD), associated behaviour problems, prosociality, and self-perceptions, in a community sample. Six hundred and thirty-five 12-year-old children (314 girls) provided peer nominations and rated feelings of loneliness and self-perceptions regarding global self-worth and behavioural conduct. We obtained teacher ratings of ADHD symptoms, conduct and internalising problems, and prosociality. ADHD symptoms, conduct problems, internalising problems, and low levels of prosociality were all related to higher levels of peer dislike. Despite ADHD symptoms being related to more peer dislike, children with high levels of ADHD symptoms did not report more feelings of loneliness. The self-perceptions of children with high levels of ADHD were not related to peer dislike. Although high levels of ADHD symptoms were not related to peer dislike in girls, peers tolerated higher levels of ADHD symptoms among boys than among girls, providing support for the “gender appropriateness hypothesis” regarding the impact and influence of ADHD symptomatology upon the peer relations of children within a community sample.

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.

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.

Sex Differences in Attentional Performance in a Clinical Sample With ADHD of the Combined Subtype

OBJECTIVE

The goal of the present study was to assess whether girls with ADHD express similar deficits in various attention tasks to those described in boys.

METHOD

A total of 175 children with the combined subtype of ADHD (89 females) and 132 normal controls (60 females) aged 8 to 14 years participated. Five different tests were conducted: alertness, sustained attention, focused attention, divided attention, and a set-shifting task.

RESULTS

The children with ADHD performed worse on all aspects of attention compared with healthy control participants. Several overall general sex differences could be detected, with boys exhibiting faster reaction times and greater response variability. Controlling for ADHD symptom severity and psychiatric comorbidities, no Sex × Diagnosis interaction was found, suggesting that males and females with ADHD experience comparable attentional deficits.

CONCLUSION

These results indicate that deficits in various attentional domains are a robust component of ADHD in males and females.

Pathophysiology of ADHD and associated problems-starting points for NF interventions?

Attention deficit hyperactivity disorder (ADHD) is characterized by severe and age-inappropriate levels of hyperactivity, impulsivity and inattention. ADHD is a heterogeneous disorder, and the majority of patients show comorbid or associated problems from other psychiatric disorders. Also, ADHD is associated with cognitive and motivational problems as well as resting-state abnormalities, associated with impaired brain activity in distinct neuronal networks. This needs to be considered in a multimodal treatment, of which neurofeedback (NF) may be a promising component. During NF, specific brain activity is fed-back using visual or auditory signals, allowing the participants to gain control over these otherwise unaware neuronal processes. NF may be used to directly improve underlying neuronal deficits, and/or to establish more general self-regulatory skills that may be used to compensate behavioral difficulties. The current manuscript describes pathophysiological characteristics of ADHD, heterogeneity of ADHD subtypes and gender differences, as well as frequently associated behavioral problems such as oppositional defiant/conduct or tic disorder. It is discussed how NF may be helpful as a treatment approach within these contexts.

Efficacy of chess training for the treatment of ADHD: A prospective, open label study

OBJECTIVE

To examine the effectiveness of playing chess as a treatment option for children with ADHD.

METHODS

Parents of 44 children ages 6 to 17 with a primary diagnosis of ADHD consented to take part in the study. Parents completed the Spanish version of the Swanson, Nolan and Pelham Scale for parents (SNAP-IV) and the Abbreviated Conner's Rating Scales for parents (CPRS-HI) prior to an 11-week chess-training program. We used a paired t-test to compare pre- and post-intervention outcomes, and Cohen-d calculations to measure the magnitude of the effect. The statistical significance was set at P<.05.

RESULTS

Children with ADHD improved in both the SNAP-IV (t=6.23; degrees of freedom (df)=41; P<.001) and the CPRS-HI (t=5.39; df=33; P<.001). Our results suggest a large effect in decreasing the severity of ADHD as measured by the SNAP-IV (d=0.85) and the CPRS-HI (d=0.85). Furthermore, we found a correlation between intelligence quotient and SNAP-IV improvement (P<.05).

CONCLUSIONS

The results of our pilot study should be interpreted with caution. This pilot project highlights the importance of carrying out larger studies with a case-control design. If our results are replicated in better designed studies, playing chess could be included within the multimodal treatment of ADHD.

Co-occurrence of attention-deficit hyperactivity disorder symptoms with other psychopathology in young adults: parenting style as a moderator

The extent to which parenting styles can influence secondary psychiatric symptoms among young adults with ADHD symptoms is unknown. This issue was investigated in a sample of 2284 incoming college students (male, 50.6%), who completed standardized questionnaires about adult ADHD symptoms, other DSM-IV symptoms, and their parents' parenting styles before their ages of 16. Among them, 2.8% and 22.8% were classified as having ADHD symptoms and sub-threshold ADHD symptoms, respectively. Logistic regression was used to compare the comorbid rates of psychiatric symptoms among the ADHD, sub-threshold ADHD and non-ADHD groups while multiple linear regressions were used to examine the moderating role of gender and parenting styles over the associations between ADHD and other psychiatric symptoms. Both ADHD groups were significantly more likely than other incoming students to have other DSM-IV symptoms. Parental care was negatively associated and parental overprotection/control positively associated with these psychiatric symptoms. Furthermore, significant interactions were found of parenting style with both threshold and sub-threshold ADHD in predicting wide-ranging comorbid symptoms. Specifically, the associations of ADHD with some externalizing symptoms were inversely related to level of paternal care, while associations of ADHD and sub-threshold ADHD with wide-ranging comorbid symptoms were positively related to level of maternal and paternal overprotection/control. These results suggest that parenting styles may modify the effects of ADHD on the risk of a wide range of temporally secondary DSM-IV symptoms among incoming college students, although other causal dynamics might be at work that need to be investigated in longitudinal studies.

Systematic evidence synthesis of treatments for ADHD in children and adolescents: indirect treatment comparisons of lisdexamfetamine with methylphenidate and atomoxetine

OBJECTIVE

Systematically review and synthesize the clinical evidence of treatments for attention deficit hyperactivity disorder (ADHD) by indirectly comparing established treatments in the UK with a drug recently approved in Europe (lisdexamfetamine [LDX]).

POPULATION

children and adolescents.

SETTING

Europe. Comparators: methylphenidate (MPH), atomoxetine (ATX), and dexamphetamine (DEX). Electronic databases and relevant conference proceedings were searched for randomized, controlled clinical trials evaluating efficacy and safety of at least one of the comparators and LDX. Quality assessments for each included trial were performed using criteria recommended by the Centre for Reviews and Dissemination. Network meta-analysis methods for dichotomous outcomes were employed to evaluate treatment efficacy.

MAIN OUTCOME MEASURES

Response, as defined by either a reduction from baseline of at least 25% in the ADHD Rating Scale [ADHD-RS] total score or, separately, as assessed on the Clinical Global Impression-Improvement [CGI-I] scale, and safety (all-cause withdrawals and withdrawal due to adverse events).

RESULTS

The systematic review found 32 trials for the meta-analysis, including data on LDX, ATX, and different formulations of MPH. No trials for DEX meeting the inclusion criteria were found. Sufficient data were identified for each outcome: ADHD-RS, 16 trials; CGI-I, 20 trials; all-cause withdrawals, 28 trials; and withdrawals due to adverse events, 27 trials. The relative probability of treatment response for CGI-I (95% confidence intervals [CI]) for ATX versus LDX was 0.65 (0.53-0.78); for long-acting MPH versus LDX, 0.82 (0.69-0.97); for intermediate release MPH versus LDX, 0.51 (0.40-0.65); and for short-acting MPH versus LDX, 0.62 (0.51-0.76). The relative probabilities of ADHD-RS treatment response also favored LDX.

CONCLUSIONS

For the treatment of ADHD, the synthesis of efficacy data showed statistically significant better probabilities of response with LDX than for formulations of MPH or ATX. The analysis of safety data proved inconclusive due to low event rates. These results may be limited by the studies included, which only investigated the short-term efficacy of medications in patients without comorbid disorders.

Factors contributing to the utilization of adult mental health services in children and adolescents diagnosed with hyperkinetic disorder

Objectives. To examine whether age of First diagnosis, gender, psychiatric comorbidity, and treatment modalities (pharmacotherapy or psychotherapy) at Child and Adolescent Mental Health Services (CAMHS) moderate the risk of Adult Mental Health Services (AMHS) utilization in patients diagnosed with hyperkinetic disorder at CAMHS. Methods. Data were derived from the Madrid Psychiatric Cumulative Register Study. The target population comprised 32,183 patients who had 3 or more visits at CAMHS. Kaplan-Meier curves were used to assess survival data. A series of logistic regression analyses were performed to study the role of age of diagnosis, gender, psychiatric comorbidity, and treatment modalities. Results. 7.1% of patients presented with hyperkinetic disorder at CAMHS. Compared to preschool children, children and adolescents first diagnosed with hyperkinetic disorder at CAMHS were more likely to use AMHS. Female gender and comorbidity with affective disorders, schizophrenia, schizotypal and delusional disorders increased the risk of use of AMHS. Pharmacological or combined treatment of hyperkinetic disorder diagnosed at CAMHS was associated with increased risk of use at AMHS. Conclusions. Older age of first diagnosis, female gender, psychiatric comorbidity, and pharmacological treatment at CAMHS are markers of risk for the transition from CAMHS to AMHS in patients with hyperkinetic disorder diagnosed at CAMHS.

Amfetamine and methylphenidate medications for attention-deficit/hyperactivity disorder: complementary treatment options

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders among school-aged children. It is highly symptomatic and associated with significant impairment. This review examines the role of stimulant medications in the treatment of children and adolescents with ADHD. Published clinical studies that compared methylphenidate- and amfetamine-based stimulants in children and adolescents with ADHD support the therapeutic utility of stimulant treatments, and suggest robust efficacy and acceptable safety outcomes in groups treated with either stimulant. Evidence-based guidelines agree that each patient with ADHD is unique and individual treatment strategies that incorporate both drug and non-drug treatment options should be sought. In seeking to optimize individual response and outcomes to stimulant therapy, important considerations include the selection of stimulant class, the choice of long- or short-acting stimulant formulations, addressing effectively any emergent adverse effects and strategies aimed at enhancing adherence to dosing regimen and persistence on therapy.

Neuropsychological profile of executive function in girls with attention-deficit/hyperactivity disorder

The majority of research on neurobehavioral functioning among children with Attention-Deficit/Hyperactivity Disorder (ADHD) is based on samples comprised primarily (or exclusively) of boys. Although functional impairment is well established, available research has yet to specify a neuropsychological profile distinct to girls with ADHD. The purpose of this study was to examine performance within four components of executive function (EF) in contemporaneously recruited samples of girls and boys with ADHD. Fifty-six children with ADHD (26 girls) and 90 controls (42 girls), ages 8-13, were administered neuropsychological tests emphasizing response inhibition, response preparation, working memory, and planning/shifting. There were no significant differences in age or SES between boys or girls with ADHD or their sex-matched controls; ADHD subtype distribution did not differ by sex. Compared with controls, children with ADHD showed significant deficits on all four EF components. Girls and boys with ADHD showed similar patterns of deficit on tasks involving response preparation and working memory; however, they manifested different patterns of executive dysfunction on tasks related to response inhibition and planning. Girls with ADHD showed elevated motor overflow, while boys with ADHD showed greater impairment during conscious, effortful response inhibition. Girls, but not boys with ADHD, showed impairment in planning. There were no differences between ADHD subtypes on any EF component. These findings highlight the importance of studying boys and girls separately (as well as together) when considering manifestations of executive dysfunction in ADHD.

Girls with social and/or attention deficits: a descriptive study of 100 clinic attenders

OBJECTIVE

Examine clinical correlates and distinguishing features of autism spectrum disorders (ASD), ADHD, and tic disorders in girls referred for social impairment, attention/academic deficits, and/or tics.

METHOD

One hundred 3- to 18-year-old girls referred for social impairment and attention symptoms were assessed in detail. Sixty of these girls, 7 to 16 years of age (IQ >or= 80) were compared with age-matched girls (IQ >or= 80) from the community.

RESULTS

Main diagnoses of ASD, ADHD, tic disorders, and "other psychiatric disorder" were made in 46, 46, 3, and 5, respectively, of the referred girls. The ASD and ADHD groups (mean age at diagnosis 8.8 and 13.0 years, respectively) had the same types and high rates of psychiatric comorbidity. Girls with ASD had more problems with global functioning and adaptive levels of daily living skills than girls with ADHD. Differences between these girls referred for investigation and the community sample of girls were very considerable across a range of factors.

CONCLUSIONS

Girls referred for social and/or attention deficits usually meet diagnostic criteria for either ASD or ADHD. They have severe psychiatric comorbidities and low global levels of functioning.

Differences in efficacy and safety of pharmaceutical treatments between men and women: an umbrella review

Being male or female is an important determinant of risks for certain diseases, patterns of illness and life expectancy. Although differences in risks for and prognoses of several diseases have been well documented, sex-based differences in responses to pharmaceutical treatments and accompanying risks of adverse events are less clear. The objective of this umbrella review was to determine whether clinically relevant differences in efficacy and safety of commonly prescribed medications exist between men and women. We retrieved all available systematic reviews of the Oregon Drug Effectiveness Review Project published before January 2010. Two persons independently reviewed each report to identify relevant studies. We dually abstracted data from the original publications into standardized forms. We synthesized the available evidence for each drug class and rated its quality applying the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Findings, based on 59 studies and data of more than 250,000 patients suggested that for the majority of drugs no substantial differences in efficacy and safety exist between men and women. Some clinically important exceptions, however, were apparent: women experienced substantially lower response rates with newer antiemetics than men (45% vs. 58%; relative risk 1.49, 95% confidence interval 1.35–1.64); men had higher rates of sexual dysfunction than women while on paroxetine for major depressive disorder; women discontinued lovastatin more frequently than men because of adverse events. Overall, for the majority of drugs sex does not appear to be a factor that has to be taken into consideration when choosing a drug treatment. The available body of evidence, however, was limited in quality and quantity, confining the range and certainty of our conclusions.

Gender differences in attention-deficit/hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is recognized to exist in males and females although the literature supports a higher prevalence in males. However, when girls are diagnosed with ADHD, they are more often diagnosed as predominantly inattentive than boys with ADHD. This article provides a review of gender differences noted across the lifespan. Males and females with ADHD are more similar than different, and generally ADHD profiles are not sex specific. Small gender differences have been found: adolescent girls with ADHD have lower self-efficacy and poorer coping strategies than adolescent boys with ADHD; rates of depression and anxiety may be higher, and physical aggression and other externalizing behaviors lower in girls and women with ADHD. Men with ADHD seem to be incarcerated more often than women with ADHD. However, many studies suffer from small sample sizes, referral biases, differences in diagnostic procedures, and possible rater influences. Treatments are reviewed and discussed with reference to the reported gender differences in functioning and the global deficits noted in all samples. The data available so far suggest that treatments are likely to be equally effective in males and females. However, referral bias is a problem, in that females with ADHD are less likely to be referred for treatment than males with ADHD. Future research should include equal representation of both sexes in samples such that sex by treatment analyses can be routinely conducted.

Five Years On: Public Sector Service Use Related to Mental Health in Young People with ADHD or Hyperkinetic Disorder Five Years After Diagnosis

BACKGROUND

  Little is known about ongoing service use among young people with ADHD, but this information is important to the development of services to support these young people.

METHODS

  A cohort of young people with ADHD or hyperkinetic disorder (n = 115) was followed up five to seven years after diagnosis. Details are presented of their use of public sector services over the 12 months preceding reassessment, compared to young people with ADHD from a large epidemiological study.

RESULTS

  Most children remained in contact with CAMHS, with high rates of contact with schools, educational professionals and the criminal justice system. Nearly all had taken medication at some point, while many still were using it. There were low reported rates of psychological and group interventions within the last twelve months, but this does not rule out earlier access to such treatments.

CONCLUSIONS

  Children with ADHD utilise long-term support from public sector services, and cross agency strategies or clinics may help to optimise functioning.

Gender differences in ADHD: implications for psychosocial treatments

Attention-deficit/hyperactivity disorder (ADHD) has now been recognized to exist in both males and females, albeit the literature supports a higher prevalence in males. However, when girls are diagnosed with ADHD, they are more often diagnosed as predominantly inattentive than boys with ADHD. This paper provides a review of gender differences noted across the lifespan in terms of psychosocial functioning, cognitive abilities and psychiatric comorbidities. Males and females with ADHD are more similar than different, and generally symptoms of ADHD are not sex specific. Small gender differences have been found: adolescent girls with ADHD have lower self-efficacy and poorer coping strategies than adolescent boys with ADHD, but these differences tend to disappear by adulthood; rates of depression and anxiety may be higher (especially in adolescence) while physical aggression and other externalizing behaviors may be lower in girls and women with ADHD, although not all studies support these findings (e.g., non-referred samples show similar rates of coexisting psychiatric disorders between boys and girls with ADHD). However, many studies suffer from small sample sizes, referral biases, differences in diagnostic procedures and possible rater influences. Psychosocial treatments are reviewed and discussed with reference to the reported gender differences in functioning as well as the global deficits noted in all samples. Although the data available so far suggest that psychosocial treatments are likely to be equally effective in males and females, this conclusion is based more on the small number of gender differences noted in overall functioning and less on empirical research on treatment by sex effects and the moderating role of sex, an effect only investigated by the Multi-modal Treatment Study of ADHD group, to date. Future research should include equal representation of both sexes in samples such that treatment analyses by gender can be routinely conducted.

Is NICE infallible? A qualitative study of its assessment of treatments for attention-deficit/hyperactivity disorder (ADHD)

BACKGROUND

Conclusions of the recent NICE technology appraisal of treatments for attention-deficit/hyperactivity disorder (ADHD) differ from recommendations by other Health Technology Assessment (HTA) agencies, such as the Scottish Medicines Consortium (CMS) and the Australian Pharmaceutical Benefits Advisory Committee (PBAC). NICE did not identify differences on grounds of clinical effectiveness between treatment options studied and issued technology guidance based on clinical profiles of compounds and on drug acquisition costs. The aim of the present study was to explore the robustness of NICE assessment methods when addressing a complex clinical problem such as the evaluation of ADHD treatment strategies. This robustness will be of interest to international policy-makers, given the widespread perception of NICE as a role model for the implementation of HTAs including economic evaluation.

METHODS

A qualitative case study was performed to critically appraise the technology assessment report (AR) underlying NICE conclusions, including a systematic search for and analysis of relevant literature.

RESULTS

The AR produced on behalf of NICE was found to exhibit a range of anomalies. Search criteria were not applied consistently, and the available clinical evidence was not used optimally; selection of clinical endpoints and clinical trials for analysis were idiosyncratic. The primary cost-effectiveness model relied on six short-term studies only, and secondary extensions combined heterogeneous study designs and different clinical endpoints. Neither the distinction between efficacy and effectiveness nor the role of treatment compliance in ADHD was addressed adequately. Long-term extensions of the model were impaired by use of inappropriate discount rates and absence of consideration of long-term sequelae associated with ADHD.

CONCLUSION

A review of the literature strongly suggests that the NICE assessment of ADHD treatment strategies was incomplete and likely prone to bias. It is concluded that NICE did not adequately accommodate a complex clinical decision problem. Although the present qualitative case study of one assessment cannot, and was not designed to, invalidate the NICE approach to economic evaluation of healthcare programs, this observation may have potentially far-reaching implications for the generalizability of NICE-like approaches.

The NICE ADHD health technology assessment: a review and critique

BACKGROUND

Health technology assessments (HTAs) by the National Institute for Health and Clinical Excellence (NICE) enjoy high levels of international attention. The present analysis addresses NICE's appraisal of methylphenidate, atomoxetine and dexamphetamine for attention-deficit/hyperactivity disorder (ADHD) in children and adolescents, published in March 2006.

METHODS

A qualitative study of NICE Technology Appraisal No. 98 was done focusing on the >600-page technology assessment report, which aimed at evaluating ADHD treatment strategies by a clinical effectiveness review and an economic analysis using meta-analytical techniques and a cost-effectiveness model.

RESULTS

The technology assessment was unable to differentiate between the various drugs in terms of efficacy, and its economic model was ultimately driven by cost differences. While the assessment concluded that the economic model "clearly identified an optimal treatment strategy" with first-line dexamphetamine, the NICE appraisal committee subsequently found it impossible to distinguish between the different strategies on grounds of cost-effectiveness. Analyzing the assessment reveals gaps and inconsistencies concerning data selection (ultimately relying on a small number of short-term studies only), data synthesis (pooling of heterogeneous study designs and clinical endpoints), and economic model structure (identifying double-counting of nonresponders as a likely source of bias, alongside further methodological anomalies).

CONCLUSION

Many conclusions of the NICE technology assessment rest on shaky grounds. There remains a need for a new, state-of-the-art systematic review of ADHD treatment strategies including economic evaluation, which ideally should address outcomes beyond children's health-related quality of life, such as long-term sequelae of the disorder and caregiver burden.

The neurobiological profile of girls with ADHD

Since boys are more commonly diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) than girls, the majority of theories and published research studies of ADHD have been based on samples comprised primarily (or exclusively) of boys. While psychosocial impairment in girls with ADHD is well established, the neuropsychological and neurobiological basis of these deficits is less consistently observed. There is growing evidence that boys' and girls' brains develop and mature at different rates, suggesting that the trajectory of early anomalous brain development in ADHD may also be sex-specific. It remains unclear, however, whether earlier brain maturation observed in girls with ADHD is protective. In this review, we outline the current theory and research findings that seek to establish a unique neurobiological profile of girls with ADHD, highlighting sex differences in typical brain development and among children with ADHD. The review highlights findings from neurological, neurocognitive, and behavioral studies. Future research directions are suggested, including the need for longitudinal neuroimaging and neurobehavioral investigation beginning as early as the preschool years, and continuing through adolescence and adulthood, with consideration of identified sex differences in the development of ADHD.

Long-acting medications for the hyperkinetic disorders. A note on cost-effectiveness

New long-acting medications for attention-deficit/ hyperactivity disorder (ADHD) have become available, which combine certain advantages over conventional short-acting drugs with higher acquisition costs. Choices between these drugs should thus be driven by their clinical profiles and by an acceptable balance of increased costs and additional benefits. Accordingly, the notion of relative cost-effectiveness should be central to recommendations about the use of these drugs in practice. A recent technology assessment on behalf of the National Institute for Health and Clinical Excellence (NICE) did not identify differences between compounds in terms of clinical efficacy and described drug cost as the major driver of cost-effectiveness. The underlying economic model was restricted to a cost-utility analysis that used only a fraction of the available clinical evidence base and did not address the distinction between efficacy and effectiveness. Cost-effectiveness evaluations including the potential impact of improved treatment compliance indicate a relatively more attractive cost-effectiveness of long-acting medications than suggested by the NICE assessment. These evaluations provide health economic support to treatment recommendations recently published by the European Network for Hyperkinetic Disorders. Limitations of currently available economic evaluations include their short time horizon, and future research should assess treatment effects on long-term sequelae associated with ADHD.

Special considerations in diagnosing and treating attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent chronic condition that affects people of all ages, including young children, school-aged children, adolescents, and adults. Symptoms can be noted as early as preschool age, tend to progress into functional impairment and behavioral problems in later childhood, and typically persist into adulthood. Contrary to previous belief, the disorder does not resolve with puberty for the majority of children; rather, the symptoms are manifested differently throughout the lifecycle. Presentation in adults is heavily biased toward inattentive symptoms, which are less likely to draw notice than hyperactive or impulsive symptoms and may contribute to the underrecognition of ADHD in this patient population. Diagnosis is particularly difficult due in large part to the pronounced comorbidity of psychiatric disorders in this patient population. Identification may be even more difficult in adults than children as the diagnostic criteria are not as clear, adults have difficulty remembering symptoms prior to 7 years of age, and there is a high prevalence of comorbid psychiatric disorders in adults. Early identification and treatment of symptoms of ADHD in preschool-age children is essential to effective long-term management of the disorder. Both medication and behavioral treatments appear to alleviate the symptoms of ADHD, and evidence suggests that discontinuation of treatment leads to the reemergence of the condition. Efforts are currently continuing toward understanding the genetic underpinnings of ADHD. This expert review supplement will address the prevalence, comorbidity, treatment issues, and special considerations surrounding ADHD management throughout each stage of the lifecycle beginning with ADHD in preschool-aged children, continuing with school-aged children and adolescents, and ending with adulthood.

Which factors impact on clinician-rated impairment in children with ADHD?

OBJECTIVES

To describe the associations between a range of demographic, family and clinical factors and clinician-rated measures of global impairment in children with ADHD symptoms obtained at the baseline assessment in the ADHD Observational Research in Europe (ADORE) study.

METHODS

Global impairment was measured by clinicians using the Clinical Global Impression-Severity (CGI-S) scale and the Children's Global Assessment Scale (CGAS). Associations with independent variables were investigated using forward-stepwise regression models.

RESULTS

For the CGI-S and CGAS analyses, complete data sets were available for 1,265 and 985 children, respectively. The baseline mean CGI-S score in this population was 4.4 (SD 0.9) and the mean CGAS score was 55.0 (SD 10.6). Factors significantly associated with increased impairment on both outcome measures were: increased severity of ADHD symptoms, increased peer relationship problems and presence of oppositional defiant disorder and/or conduct disorder. Also, the presence of anxiety and/or depression and the presence of somatic symptoms were associated with increased impairment on CGI-S,while family health problems and premature birth were associated with increased impairment on CGAS.

CONCLUSIONS

The severity of clinician-rated impairment in the ADORE sample is increased by the presence of disruptive behaviour problems and emotional problems, somatic symptoms, peer relationship difficulties, family health problems and premature birth.

Influence of gender on attention-deficit/hyperactivity disorder in Europe--ADORE

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) in girls in Europe is poorly understood; it is not known whether they exhibit similar symptom patterns or co-existing problems and receive the same type of treatment as boys.

OBJECTIVE

To examine gender differences for referral patterns, social demographic factors, ADHD core symptomatology, co-existing health problems, psychosocial functioning and treatment.

METHODS

Baseline data from the ADHD Observational Research in Europe (ADORE) study, a 24-month, naturalistic, longitudinal observational study in 10 European countries of children (aged 6-18 years) with hyperactive/inattentive/impulsive symptoms but no previous diagnosis of ADHD, were analysed by gender.

RESULTS

Data from 1,478 children were analysed: 231 girls (15.7%) and 1,222 boys (84.3%) (gender data missing for 25 patients). Gender ratios (girl:boy) varied by country, ranging from 1:3 to 1:16. Comparisons showed few gender effects in core ADHD symptomatology and clinical correlates of ADHD. Compared with boys, girls had significantly more parent-rated emotional symptoms and prosocial behaviour and were more likely to be the victim of bullying and less likely to be the bully. Girls and boys had similar levels of co-existing psychiatric and physical health problems, and received the same type of treatment.

CONCLUSIONS

Fewer girls than boys are referred for ADHD treatment, but they have a similar pattern of impairment and receive similar treatment.

Are ADHD gender patterns moderated by sample source?

OBJECTIVE

To examine whether ADHD gender patterns with respect to social-demographic characteristics, comorbidity, and impairment vary as a function of service use for emotional or behavioral problems.

METHOD

Two hundred and seventy-nine males and 119 females meeting ADHD symptom criteria identified in a nationally representative sample of Australian youth ages 6 to 17 are stratified according to whether they had attended a service in the previous 6 months.

RESULTS

ADHD gender patterns vary across service use on only 2 of the 31 comparisons made. The two exceptions were child's age at interview (females were older than males among service attendees but younger among nonattendees) and depressive disorders (females had higher rates than males among service attendees but lower rates among nonattendees).

CONCLUSION

Systematic differences in methods of case identification rather than sample source may be responsible for the discrepant ADHD patterns found between clinic and community-based studies.

Attention-deficit hyperactivity disorder in girls: epidemiology and management

Attention-deficit hyperactivity disorder (ADHD) in girls is a topic of growing research and clinical interest. For many years, girls with ADHD have been ignored and overshadowed by hyperkinetic and impulsive boys, but they are now attracting interest in an effort to understand the similarities and differences in the prevalence, symptoms, familial risk, comorbidities and treatment of ADHD in the two sexes. A review of past and current literature finds that the symptoms of ADHD are not sex specific, but that identification of girls with ADHD is hampered by parental and teacher bias, and confusion. Girls are more likely to be inattentive without being hyperactive or impulsive, compared with boys. Girls and boys share the same familial risk patterns, as well as similar, although not identical, comorbidity or impairment patterns. The risk of non-treatment is as great in girls as it is in boys; up to 70-80% of identified children will have persistent symptoms and impairment that extends into adolescence and adulthood. Treatment modalities are equally effective in girls and boys. Stimulants, non-stimulants and behavioural modalities are the mainstays of effective treatment.

Neuropsychological functioning in people with ADHD across the lifespan

ADHD is defined by behavioral characteristics similar to neuropsychological disorders of executive dysfunction. This paper is a literature review of the neurocognitive characteristics of ADHD from early childhood through adulthood. The author addresses the development of the concept of attention and executive function (EF) deficits in ADHD, clinical neuropsychological studies of pre-teenage children, teenagers and adults with ADHD, gender and the role of psychiatric co-morbidity including the relationship of learning disabilities to ADHD, heterogeneity of neuropsychological dysfunctions, experimental neuropsychological studies, the relationship of brain structure to function, psychopharmacology of ADHD, and clinical neuropsychological assessment. The group data clearly supports the hypothesis that executive dysfunctions are correlates of ADHD regardless of gender and age, and these EF deficits are exacerbated by co-morbidity with learning disabilities such as dyslexia. However, there is limited data on children under the age of 5, teenagers from age 13-18, and adults with ADHD over the age of 40. Studies of individual classification of people with ADHD compared to healthy, non-psychiatric controls do not support the use of neuropsychological tests for the clinical diagnosis of ADHD, and indicate that not all persons with ADHD have EF deficits. Some persons with ADHD may have deficits in brain reward systems that are relatively independent of EF impairments. Future research should clarify the multiple sources of ADHD impairments, continue to refine neuropsychological tools optimized for assessment, and incorporate longitudinal, developmental designs to understand ADHD across the lifespan.

Brain development and ADHD

Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by excessive inattention, hyperactivity, and impulsivity, either alone or in combination. Neuropsychological findings suggest that these behaviors result from underlying deficits in response inhibition, delay aversion, and executive functioning which, in turn, are presumed to be linked to dysfunction of frontal-striatal-cerebellar circuits. Over the past decade, magnetic resonance imaging (MRI) has been used to examine anatomic differences in these regions between ADHD and control children. In addition to quantifying differences in total cerebral volume, specific areas of interest have been prefrontal regions, basal ganglia, the corpus callosum, and cerebellum. Differences in gray and white matter have also been examined. The ultimate goal of this research is to determine the underlying neurophysiology of ADHD and how specific phenotypes may be related to alterations in brain structure.

A post hoc subgroup analysis of an 18-day randomized controlled trial comparing the tolerability and efficacy of mixed amphetamine salts extended release and atomoxetine in school-age girls with attention-deficit/hyperactivity disorder

BACKGROUND

Because the scientific literature on the pharmacotherapy of attention-deficit/hyperactivity disorder (ADHD) is almost entirely based on the results of studies in samples consisting primarily of boys, much is unknown about the treatment response in girls.

OBJECTIVE

This post hoc analysis compared the efficacy, tolerability, and time course of the effect of mixed amphetamine salts extended release (MAS XR) and atomoxetine in school-age girls with ADHD.

METHODS

This was an intent-to-treat subanalysis of the data from girls enrolled in a multicenter, 18-day, randomized, double-blind, parallel-group, forced dose-titration, laboratory school study enrolling boys and girls aged 6 to 12 years with ADHD. The study compared the efficacy, tolerability, and time course of the effect of increasing doses of MAS XR (10, 20, and 30 mg/d) and atomoxetine (0.5 and 1.2 mg/kg per day). The laboratory school sessions were organized in cycles to include 12 hours of observation. Efficacy measures included the SKAMP (Swanson, Kotkin, Agler, M-Flynn, and Pelham) deportment rating subscale, the SKAMP attention rating subscale, and academic testing (number of math problems attempted and answered correctly). Adverse events were assessed throughout the study period. Tolerability and efficacy measures were assessed during laboratory school visits on days 7, 14, and 21.

RESULTS

This subanalysis included 57 girls (median age, 9 years; 49.1% white, 22.8% black, 17.5% Hispanic) with a diagnosis of ADHD, combined subtype. Twenty-six girls were randomized to receive MAS XR and 31 were randomized to receive atomoxetine. Mean SKAMP deportment and attention subscale scores in the 2 groups were similar at baseline. Mean changes from baseline were significantly greater for MAS XR compared with atomoxetine on the SKAMP deportment score (-0.48 vs -0.04, respectively; P<0.001) and SKAMP attention score (-0.45 vs -0.05; P<0.001). The time course of medication effect, based on change from baseline in SKAMP deportment scores, indicated 12-hour efficacy for MAS XR at hours 2, 4.5, 7, 9.5, and 12 (all time points, P<0.01 vs baseline) but not for atomoxetine. At the end of the study, both treatment groups had a significant increase from baseline in the mean number of math problems attempted and answered correctly (P<0.001). Girls who received MAS XR attempted significantly greater numbers of problems compared with those who received atomoxetine (P=0.04). Both MAS XR and atomoxetine were well tolerated. The most frequently occurring treatment-related adverse events in girls receiving MAS XR were decreased appetite (40.7%), upper abdominal pain (29.6%), insomnia (25.9%), and headache (14.8%). The most frequently occurring treatment-related adverse events in girls receiving atomoxetine were somnolence (28.1%), upper abdominal pain (15.6%), vomiting (15.6%), nausea (12.5%), and decreased appetite (12.5%).

CONCLUSION

This post hoc analysis in a subpopulation of girls with ADHD, combined subtype, found that 18-day treatment with MAS XR was significantly more effective than atomoxetine in terms of ratings of classroom behavior, attention, and academic productivity.

Neuropsychological functioning in girls with attention-deficit/hyperactivity disorder with and without learning disabilities

The authors' goal was to assess neuropsychological performance in girls with attention-deficit/hyperactivity disorder (ADHD) and evaluate the role of comorbid learning disabilities (LDs). Participants were 140 girls with ADHD and 122 girls without ADHD, ages 6-17 years. Neuropsychological performance was measured in a standardized manner, blind to clinical status. LD was defined by a combined regression-based and low-achievement classification. ADHD was associated with modest, but significant, neuropsychological impairment, as measured with an aggregate measure of performance and with the Stroop Color-Word Test, independent of age, social class, IQ, and psychiatric comorbidity. Neuropsychological deficits were most pronounced in girls with both ADHD and an LD and in those without medications. These results extend to females the previously documented association of LDs with neuropsychological functioning in males with ADHD.

Treating adolescent girls and women with ADHD: gender-specific issues

Attention deficit hyperactivity disorder (ADHD), commonly diagnosed in males, is often a "hidden disorder" in girls and women. This lack of recognition can be partially explained because the symptoms are less overt in females. In addition, coexisting disorders in females are often different from those seen in males who have ADHD. Higher rates of anxiety, mood, and substance disorders, as well as learning disabilities, often complicate the picture. Thus, clinicians are challenged with disentangling the symptoms of ADHD from symptoms of these coexisting conditions. In addition, fluctuating hormone levels may affect ADHD symptoms and treatment in females. Only with gender-sensitive diagnosis and treatment will the public health concern posed by the underdiagnosis of ADHD in females be addressed. This case report of a 23-year-old female illustrates the specific difficulties with the gender-sensitive aspects of the diagnosis and treatment of ADHD in females.

Gender appropriateness of symptom criteria for attention-deficit/hyperactivity disorder, oppositional-defiant disorder, and conduct disorder

We examined the gender appropriateness of the DSM-IV symptoms of attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD). In Study 1, 100 mothers (35 of children with and 65 of children without ADHD) rated how gender-typical and problematic they saw DSM-IV symptoms of ADHD, ODD, and CD; feminine descriptions of ADHD, ODD, and CD behaviors that we created; and relationally and overtly aggressive behaviors. Mothers rated the DSM-IV symptoms and overt aggression as boy-descriptive, and the feminine items that we created and relational aggression as girl-descriptive. Mothers saw the feminine items as less problematic than the masculine items. In Study 2, for 80 girls (40 with and 40 without ADHD), mothers' ratings on the feminine items were related to the corresponding DSM-IV symptoms, and to general psychopathology and impairment. Most correlations were significant and support the construct validity of the feminine items.

Impact of gender and age on executive functioning: do girls and boys with and without attention deficit hyperactivity disorder differ neuropsychologically in preteen and teenage years?

ADHD is known to have neuropsychological correlates, characterized mainly by executive function (EF) deficits. However, most available data are based on studies of boys through age 12. Our goal was to assess whether girls with ADHD express neuropsychological features similar to those found in boys, and whether these impairments are found in both preteen and teen samples. Participants were 101 girls and 103 boys with DSM-III-R ADHD, and 109 comparison girls and 70 boys without ADHD, ages 9 to 17 years. Information on neuropsychological performance was obtained in a standardized manner blind to clinical status. Primary regression analyses controlled for age, socioeconomic status, learning disability, and psychiatric comorbidity. Girls and boys with ADHD were significantly more impaired on some measures of EFs than healthy comparisons but did not differ significantly from each other. With the exception of 1 test score there were no significant Sex x Diagnosis interactions. Moreover, there were no more significant interactions among age, gender, and diagnosis than would be expected by chance. Neuropsychological measures of EFs were comparably impaired in girls compared to boys with ADHD, and these impairments are found at ages 9 to 12 and ages 13 to 17. These findings suggest that executive dysfunctions are correlates of ADHD regardless of gender and age, at least through the late teen years.

Support for association between ADHD and two candidate genes: NET1 and DRD1

Attention deficit hyperactivity disorder (ADHD) is a common, multifactorial disorder with significant genetic contribution. Multiple candidate genes have been studied in ADHD, including the norepinephrine transporter (NET1) and dopamine D1 receptor (DRD1). NET1 is implicated in ADHD because of the efficacy of atomoxetine, a selective noradrenergic reuptake inhibitor, in the treatment of ADHD. DRD1 is primarily implicated through mouse models of ADHD. DNA from 163 ADHD probands, 192 parents, and 129 healthy controls was used to investigate possible associations between ADHD and polymorphisms in 12 previously studied candidate genes (5-HT1B, 5-HT2A, 5-HT2C, ADRA2A, CHRNA4, COMT, DAT1, DRD1, DRD4, DRD5, NET1, and SNAP-25). Analyses included case-control and family-based methods, and dimensional measures of behavior, cognition, and anatomic brain magnetic resonance imaging (MRI). Of the 12 genes examined, two showed a significant association with ADHD. Transmission disequilibrium test (TDT) analysis revealed significant association of two NET1 single nucleotide polymorphisms (SNPs) with ADHD (P < or = 0.009); case-control analysis revealed significant association of two DRD1 SNPs with ADHD (P < or = 0.008). No behavioral, cognitive, or brain MRI volume measurement significantly differed across NET1 or DRD1 genotypes at an alpha of 0.01. This study provides support for an association between ADHD and polymorphisms in both NET1 and DRD1; polymorphisms in ten other candidate genes were not associated with ADHD. Because family-based and case-control methods gave divergent results, both should be used in genetic studies of ADHD.

A large, double-blind, randomized clinical trial of methylphenidate in the treatment of adults with attention-deficit/hyperactivity disorder

BACKGROUND

The few controlled studies of methylphenidate (MPH) in adults with attention deficit/hyperactivity disorder (ADHD) have reported equivocal results. A previous, pilot study by our group suggested that these results were due to inadequate dosing.

METHOD

We conducted a randomized, 6-week, placebo-controlled, parallel study of MPH in 146 adult patients with DSM-IV ADHD using standardized instruments for diagnosis, separate assessments of ADHD, depressive and anxiety symptoms, and a robust average oral daily dose of 1.1 mg/kg/day.

RESULTS

We found a marked therapeutic response for the MPH treatment of ADHD symptoms that exceeded the placebo response (76% vs. 19%). Treatment was safe and well tolerated. Response to MPH was independent of socioeconomic status, gender, and lifetime history of psychiatric comorbidity.

CONCLUSIONS

These results confirm that robust doses of MPH are effective in the treatment of adult ADHD.

Calibration of ADHD Assessments Across Studies: A Meta-Analysis Tool

When analyzed separately, data from small studies provide only limited information with limited clinical generalizability, due to small sample size, differing assessments, and limited scope. In this methodological paper we outline a theoretical framework for performing meta-analysis of data obtained from disparate studies using disparate tests, based on calibration of the data from such studies and tests into a unified probability scale. We apply this method to combine the data from five studies examining the diagnostic abilities of different assessments of Attention Deficit/Hyperactivity Disorder (ADHD), including behavioral rating scales and EEG assessments. The studies enrolled a total of 111 subjects, 56 ADHD and 55 controls. Each individual study had a small sample focused on a specific age/gender group, for example 8 boys ages 6-10, and generally had insufficient power to detect statistically significant differences. No gender, or age comparisons were possible within any single study. However, when calibrated and combined, the data resulted in a clear separation between ADHD versus non-ADHD groups in males below the age of 16 (p < 0.001), males above the age of 16, (p = 0.015), females below the age of 16, (p = 0.0014), and females above the age of 16, (p = 0.0022). We conclude that if data from various studies using various tests are made comparable, the resulting combined sample size and the increased diversity of the combined sample lead to increased significance of the statistical tests and allow for cross-sectional comparisons, which are not possible within each individual study.

The adolescent outcome of hyperactive girls: self-report of psychosocial status

BACKGROUND

The aim of the study was to clarify the developmental risk associated with hyperactive behaviour in girls in a longitudinal epidemiological design.

METHODS

This was investigated in a follow-up study of girls who were identified by parent and teacher ratings in a large community survey of 6- and 7-year-olds as showing pervasive hyperactivity or conduct problems or the comorbid mixture of both problems or neither problem. They were later investigated, at the age of 14 to 16 years, with a detailed self-report interview technique.

RESULTS

Hyperactivity was a risk factor for later development, even allowing for the coexistence of conduct problems. Hyperactivity predicted academic problems and interpersonal relationship problems. Relationships with parents, by contrast, were not portrayed to be as problematic as relationships with peers and the opposite sex. Their psychological, social and occupational functioning was objectively rated to be more deviant and their self-report showed them to be more ambivalent about their future. There was a trend for hyperactivity to be self-reported as a risk for the development of continuing symptomatology but neither hyperactivity nor conduct problems were self-reported to be a risk for antisocial behaviour, substance misuse or low self-esteem in adolescence. However, they were at risk for the development of state anxiety.

CONCLUSIONS

The results suggested girls' pattern of functioning may differ from that of boys because girls self-report a more pervasive range of social dysfunction than that previously reported in boys.

Gender differences among children with DSM-IV ADHD in Australia

OBJECTIVE

To examine gender differences among children meeting symptom criteria for DSM-IV attention-deficit/hyperactivity disorder (ADHD) identified in a nationally representative sample of Australian children.

METHOD

From 2,404 children aged 6 to 13 years, 225 boys and 99 girls with ADHD symptoms were identified using the parent version of the Diagnostic Interview Schedule for Children and compared on parent reports of children's behavioral problems and impairment.

RESULTS

When ADHD types were collapsed into a single group, boys and girls did not differ on core symptoms, comorbidity, and impairment with the exception that girls rated higher on somatic complaints and boys had poorer school functioning. However, gender patterns were found to vary across ADHD type on impairment measures of social problems, schoolwork difficulties, and self-esteem, with boys being generally rated as more impaired in the combined and hyperactive-impulsive groups but equally or less impaired in the inattentive group.

CONCLUSIONS

The findings suggest the possibility of gender-specific risks associated with high levels of inattentive and hyperactive-impulsive symptoms indicating that ADHD subtype membership should be considered when conducting ADHD gender comparisons.

Gender differences in a clinic-referred sample of Taiwanese attention-deficit/hyperactivity disorder children

The purpose of this study was to examine gender differences within a clinic-referred sample of 6-11-year-old Taiwanese children with attention-deficit/hyperactivity disorder (ADHD)- combined subtype. The subjects were 21 girls with a diagnosis of ADHD from the 4th edition of the Diagnostic and Statistical Manual and 21 age-matched boys with ADHD. Comparisons were made of behavioral ratings, cognitive profiles, and vigilance/attention assessments between these two groups. The results found ADHD girls and ADHD boys to be statistically indistinguishable on nearly all measures except the subtests of block design (P = 0.016), the discrepancy between Performance Intelligence Quotient and Verbal Intelligence Quotient (P = 0.019), and the discrepancy between fluid and crystallized IQ (P = 0.041). In the study samples, ADHD girls and ADHD boys were strikingly similar on a wide range of measures. ADHD boys and girls in clinics may be expected to show more similarities than differences in treatment needs. However, these results should be interpreted with caution since data were only from clinic-referred samples.

Stimulant treatment of adult attention-deficit/hyperactivity disorder

Though only recently recognized as a valid disorder in adults, the clinical picture of adult ADHD is highly reminiscent of childhood ADHD,with continued associated occupational failure and academic deficits. Similarly, many adults with ADHD suffer from antisocial, depressive, and anxiety disorders. Recent work clearly documents that when therapeutic doses of MPH and amphetamine treatment are used in the treatment of adults with ADHD, they can lead to a robust clinical response that is highly consistent with that observed in pediatric studies using equipotent daily doses. As in childhood ADHD, medication remains a key component of treatment for adults with ADHD. More studies are needed to evaluate the efficacy and safety of stimulants over the long-term and their impact on quality of life.