Treatment of attentional and hyperactivity problems in children with sympathomimetic drugs: a comprehensive review

Risperidone Added to Psychostimulant in Children with Severe Aggression and Attention-Deficit/Hyperactivity Disorder: Lack of Effect on Attention and Short-Term Memory

OBJECTIVE

Professionals have periodically expressed concern that atypical antipsychotics may cause cognitive blunting in treated patients. In this study, we report data from a double-blind, randomized, controlled study of stimulant plus placebo versus combined stimulant and risperidone to evaluate the effects of the atypical antipsychotic on attention and short-term memory.

METHODS

A total of 165 (n = 83 combined treatment; n = 82 stimulant plus placebo) children with attention-deficit/hyperactivity disorder and severe physical aggression, aged 6-12 years, were evaluated with Conners' Continuous Performance Test (CPT-II) and the Wechsler Intelligence Scale for Children-III (WISC) Digit Span subscale at baseline, after 3 weeks of stimulant-only treatment, and after six additional weeks of randomized treatment (stimulant+placebo vs. stimulant+risperidone).

RESULTS

At 3 weeks, improvement on CPT-II performance (Commissions and Reaction Time Standard Error; p < 0.001) and on Digit Span memory performance (p < 0.006) was noted for the full sample. At study week 9, no difference in CPT-II or Digit Span performance was observed between the randomized groups (ps = 0.41 to 0.83).

CONCLUSIONS

Similar to other studies, we found no deleterious effects on attention and short-term memory associated with short-term use of risperidone. NCT00796302.

Combined Stimulant and Guanfacine Administration in Attention-Deficit/Hyperactivity Disorder: A Controlled, Comparative Study

OBJECTIVE

Because models of attention-deficit/hyperactivity disorder (ADHD) therapeutics emphasize benefits of both enhanced dopaminergic and noradrenergic signaling, strategies to enhance D1 and α2A agonism may yield enhanced clinical and cognitive responses. This study tested the hypothesis that combined effects of a dopamine and noradrenergic agonist, d-methylphenidate extended-release (DMPH) with guanfacine (GUAN), an α2A receptor agonist, would be clinically superior to either monotherapy and would have equal tolerability.

METHOD

An 8-week, double-blind, 3-arm, comparative trial randomized 7- to 14-year-olds with DSM-IV ADHD to GUAN (1-3 mg/day), DMPH (5-20 mg/day), or a combination (COMB) with fixed-flexible dosing. Outcome measures were the ADHD Rating Scale IV (ADHD-RS-IV) and the Clinical Global Impression-Improvement (CGI-I) scale. Data on adverse events and safety measures were obtained.

RESULTS

A total of 207 participants were randomized and received drug. Analyses showed significant treatment group main effects for ADHD-RS-IV ADHD total (p = .0001) and inattentive symptoms (p = .0001). COMB demonstrated small but consistently greater reductions in ADHD-RS-IV Inattentive subscale scores versus monotherapies (DMPH: p = .05; f(2) = .02; and GUAN: p = .02; f(2) = .02), and was associated with a greater positive response rate by CGI-I (p = .01). No serious cardiovascular events occurred. Sedation, somnolence, lethargy, and fatigue were greater in both guanfacine groups. All treatments were well tolerated.

CONCLUSION

COMB showed consistent evidence of clinical benefits over monotherapies, possibly reflecting advantages of greater combined dopaminergic and α2A agonism. Adverse events were generally mild to moderate, and COMB treatment showed no differences in safety or tolerability.

CLINICAL TRIAL REGISTRATION INFORMATION

Single Versus Combination Medication Treatment for Children With Attention Deficit Hyperactivity Disorder (Project1); http://clinicaltrials.gov/; NCT00429273.

Overview of Attention Deficit Hyperactivity Disorder in Young Children

Attention deficit hyperactivity disorder (ADHD) is a complex disorder, which can be seen as a disorder of life time, developing in preschool years and manifesting symptoms (full and/or partial) throughout the adulthood; therefore, it is not surprising that there are no simple solutions. The aim of this paper is to provide a short and concise review which can be used to inform affected children and adults; family members of affected children and adults, and other medical, paramedical, non-medical, and educational professionals about the disorder. This paper has also tried to look into the process of how ADHD develops; what are the associated problems; and how many other children and adults are affected by such problems all over the world basically to understand ADHD more precisely in order to develop a better medical and or non-medical multimodal intervention plan. If preschool teachers and clinicians are aware of what the research tells us about ADHD, the varying theories of its cause, and which areas need further research, the knowledge will assist them in supporting the families of children with ADHD. By including information in this review about the connection between biological behavior, it is hoped that preschool teachers and clinicians at all levels will feel more confident about explaining to parents of ADHD children, and older ADHD children themselves about the probable causes of ADHD.

The co-occurrence of reading disorder and ADHD: epidemiology, treatment, psychosocial impact, and economic burden

The co-occurrence of reading disorder (RD) and attention-deficit/hyperactivity disorder (ADHD) has received increasing attention. This review summarizes the epidemiology, treatment strategies, psychosocial impact, and economic burden associated with the co-occurrence of these conditions. Common genetic and neuropsychological deficits may partially explain the high degree of overlap between RD and ADHD. Children who face the additive problems of both disorders are at greater risk for academic failure, psychosocial consequences, and poor long-term outcomes that persist into adulthood. However, few studies have evaluated interventions targeted to this patient population, underscoring the importance of identifying effective multimodal treatments that address the neuropsychological deficits of RD and ADHD through carefully planned clinical research.

Bimanual Coordination Deficits in Attention Deficit/Hyperactivity Disorder (ADHD)

Although motor difficulties have been implicated in ADHD, studies investigating bimanual coordination have been few and their results inconsistent. This study examined the performance of 12 boys with ADHD combined type and their matched controls on a simple in-phase bimanual movement task (requiring symmetrical hand movements) and a complex out-of-phase bimanual movement task (requiring asymmetrical hand movements), at different designated speeds (1 and 2 Hz). Compared to controls, ADHD children were significantly more variable in both velocity and coordination, and less accurate in coordination, with the in-phase movements. For out-of-phase movements, the ADHD children were significantly more variable in velocity and coordination. These findings suggest a problem of bimanual coordination in the syndrome.

The effects of methylphenidate on word decoding accuracy in boys with attention-deficit/hyperactivity disorder

The investigation aimed to delineate the immediate effect of methylphenidate on decoding in the comorbid condition of attention-deficit/hyperactivity disorder and reading disorder. Boys with attention-deficit/hyperactivity and reading disorders (n = 25) between the ages of 7.9 and 11.7 years, with at least average intelligence and verbal processing abilities participated in a double-blind, acute, randomized, placebo-controlled crossover trial with a single dose of methylphenidate 0.3 to 0.4 mg/kg with weekly intervals between testing sessions. The test battery included tasks of attention/control functions and reading domain functions. Paired comparisons and first trial group comparison comparing performance under placebo and under methylphenidate were used. Methylphenidate selectively improved strategy/set shift (P = 0.004) and facilitated improvement both in rapid naming (P = 0.043) and word/nonword accuracy (P = 0.028/P = 0.035). These findings lend support to a possible influence of methylphenidate on cognitive attention functions related to reading skills in the comorbid group.

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.

Motor preparation, motor execution, attention, and executive functions in attention deficit/hyperactivity disorder (ADHD)

Attention and executive functions were investigated in medicated and unmedicated children with ADHD combined type using a novel selective reaching task. This task involved responding as rapidly as possible to a target while at times having to ignore a distractor. Results indicated that unmedicated children with ADHD showed slow and inaccurate responding. Slow responding reflected problems at the stage of movement preparation but not movement execution. An attentional impairment, rather than a motor planning problem per se, appeared to underlie the slow movement preparation. Inaccurate responding reflected problems with response inhibition and selective attention, impulsivity, set-shifting, and difficulties in maintaining vigilance. Although medicated children with ADHD did not show slow movement preparation, they did show some response inaccuracy, resulting especially from impulsive responding. These findings suggest that ADHD is characterized by slow motor preparation (but not motor execution), and deficits in selective attention, vigilance, and executive functions. Preliminary results suggest that stimulant medication may resolve some of these motor, attentional and executive function deficits.

Observations of early triadic family interactions: Boundary disturbances in the family predict symptoms of depression, anxiety, and attention-deficit/hyperactivity disorder in middle childhood

This article argues for the importance of focusing explicitly on the construct of boundary disturbances in families to understand the development of depressive, anxious, and attention-deficit/hyperactivity disorder (ADHD) symptoms in middle childhood. Grounded in family systems theory, this study examined traditional parent-child antecedents of childhood depression and anxiety (hostile, controlling, and disengaged interactions) in the context of the entire family as well as enmeshed patterns, whereby one parent drew in the child by turning to the child for caregiving or intimacy and excluded the spouse, and balanced patterns, whereby all family members expressed vulnerabilities and asserted their needs or desires. Mostly White, middle-class mothers, fathers, and children were observed at home interacting on a series of everyday tasks when the children were 24 months old, and mothers and teachers rated children's symptoms of anxiety, depression, somatic problems, and ADHD at age 7. Regression analyses revealed that, after controlling for maternal depression and the effects of other family patterns, enmeshed family patterns forecast children's depressive symptoms; controlling and disengaged interactions predicted anxious and depressive symptoms; and hostility forecast ADHD and somatic complaints. Intriguing gender differences emerged. As predicted, whereas boys who experienced enmeshed family patterns more often developed symptoms of ADHD, girls who experienced enmeshed family interactions later showed symptoms of depression.

Academic achievement and emotional status of children with ADHD treated with long-term methylphenidate and multimodal psychosocial treatment

OBJECTIVE

To test the hypothesis that intensive multimodal psychosocial intervention (that includes academic assistance and psychotherapy) combined with methylphenidate significantly enhances the academic performance and emotional status of children with attention-deficit/hyperactivity disorder (ADHD) compared with methylphenidate alone and with methylphenidate combined with nonspecific psychosocial treatment (attention control).

METHOD

One hundred three children with ADHD (ages 7-9), free of conduct and learning disorders, who responded to short-term methylphenidate were randomized for 2 years to receive one of three treatments: (1) methylphenidate alone, (2) methylphenidate plus psychosocial treatment that included academic remediation, organizational skills training, and psychotherapy as well as parent training and counseling and social skills training, or (3) methylphenidate plus attention control treatment. Children's function was assessed through academic testing, parent ratings of homework problems, and self-ratings of depression and self-esteem.

RESULTS

No advantage was found on any measure of academic performance or emotional status for the combination treatment over methylphenidate alone and over methylphenidate plus attention control. Significant improvement occurred across all treatments and was maintained over 2 years.

CONCLUSIONS

In stimulant-responsive young children with ADHD without learning and conduct disorders, there is no support for academic assistance and psychotherapy to enhance academic achievement or emotional adjustment. Significant short-term improvements were maintained over 2 years.

Longer term effects of stimulant treatments for Attention-Deficit/Hyperactivity Disorder

Of pharmacological options available for Attention-Deficit/Hyperactivity Disorder (ADHD), stimulant medications are the most studied, the most commonly used, the most effective, and the first-line choice for treatment. Evidence of the short-term efficacy of methylphenidate (MPH) and other stimulants as well as behavioral treatments in the management of symptoms of ADHD is abundant This paper reviews therapeutic trials with a duration or follow-up period of 12 months or more and evaluates the longer term outcomes of available treatments for ADHD. The trials were reported by Ialongo et al. (1993), Horn et al. (1991), Schachar, Tannock, Cunningham, and Corkum (1997), Gillberg et al. (1997), Hechtman and Abikoff (1995), and the National Institute of Mental Health (MTA Cooperative Group, 1999a, 1999b).

Handlungskontrolldefizite und störungsspezifische Zielintentionen bei der Hyperkinetischen Störung

Zusammenfassung. Theoretischer Hintergrund: Diesem Beitrag liegt ein handlungspsychologisches Rahmenmodell hyperkinetischer Verhaltensauffälligkeiten zugrunde. Fragestellung: Zwei daraus ableitbare Erklärungsansätze, die hyperkinetisches Verhalten auf störungsspezifische stimulationsbezogene Zielintentionen bzw. auf Handlungskontrolldefizite bei der Abschirmung von Zielintentionen zurückführen, werden experimentell überprüft. Methode: Dazu bearbeiteten 15 HKS-Kinder und 15 Kontrollkinder einen Continuous Performance Test (CPT-AX). Als anschließende Zweitaufgabe sollten Tiernamen genannt werden. Zur Variation des Stimulationsgrades bei der CPT-Bearbeitung wurde phasenweise Rockmusik dargeboten. Zur Variation der Abschirmanforderung bei der CPT-Bearbeitung wurden phasenweise Tierdias präsentiert, die auf die spätere Zweitaufgabe bezogen waren. Ergebnisse: Die CPT-Leistung hyperkinetischer Kinder verbesserte sich unter akustischer Stimulation, diejenige unauffälliger Kontrollkinder nicht. Unauffällige Kontrollkinder verbesserten sich unter hoher Abschirmanforderung, hyperkinetische Kinder jedoch nicht. Schlussfolgerung: Dieses Ergebnismuster kann im Sinne unseres Rahmenmodells als Hinweis auf HKS-spezifische Zielintentionen und Handlungskontrolldefizite interpretiert werden.

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.

Chronic amphetamine exposure during the preweanling period does not affect avoidance learning or novelty-seeking of adult rats

The purpose of the present study was to determine whether exposure to amphetamine during the preweanling period would impact the learning or reward processes of rats tested in adulthood. In three experiments we examined whether amphetamine treatment (0-10 mg/kg per day) on postnatal days 11-17 altered the subsequent performance of adult Sprague-Dawley rats on a step-down passive avoidance, active avoidance, or novelty-seeking task. There was no evidence that postnatal amphetamine exposure affected performance on any of these tasks. These results suggest that the long-term impact of pre- and postnatal psychostimulant exposure differs, because in utero stimulant treatment is known to produce learning deficits and decrease reinforcement efficacy of rats tested in adulthood.

Stimulant effects in attention deficit hyperactivity disorder: theoretical and empirical issues

The explanatory utility of a theory or model of ADHD or any disorder depends fundamentally on its capacity to address issues of causality. What causes a particular child to develop ADHD? What mechanisms are responsible for temporal and setting-related variations in symptom severity, and how are these mechanisms affected by pharmacological intervention? And, what processes determine whether gains in one domain will propagate across one or more others? It should be evident from the foregoing discussion that comprehensive answers to such questions are most likely to emerge through implementation of research strategies that (a) integrate biological and psychological levels of explanation, (b) permit analysis of causal hypotheses, and (c) address mechanisms involved in both etiology and mediation of treatment response. Although extant neurobiological studies of ADHD are as compelling as they are exciting, they are limited by a troubling reductionistic emphasis. The predominant animal models focus on a narrow range of behaviors that are presumed to be central to ADHD because of the topographic similarity they bear to those represented by the diagnostic criteria incorporated into the diagnostic nomenclature. These models would become increasingly valuable to the extent that future research examined the extent to which ecologically relevant behaviors (e.g., social behavior) are compromised in the animal strains and whether the observed compromises are parallel to the correlates of ADHD observed in humans. Similarly, human molecular genetic studies have provided a glimpse into the possible role that genes related to dopaminergic neurotransmission may play in the etiology of ADHD. Yet, the features of ADHD have been conceptualized in these investigations as a unitary collection of characteristics, and this has precluded analysis of what specific syndromal feature (if any single one) is affected by the implicated genes. It is intriguing to speculate whether varying combinations of genes governing properties of DA receptors and reuptake molecules are associated with different patterns of symptom severity or responses to stimulant medications. As testing procedures for determining genotypes with respect to these features become more affordable and available, it should become increasingly feasible to examine such issues empirically. Research on the utility of stimulant drugs as a treatment for ADHD also has yielded useful information. Although the effects of MPH are of short duration, the breadth of their impact is impressive. The clinical effectiveness of these medications is no longer in doubt, and patterns of relations among outcome measures represent a potentially fruitful target of scientific inquiry. Finally, data supporting a neurobiological substrate for ADHD, evidence indicating that task and setting variables moderate the expression of the syndrome's diagnostic features (see Barkley, 1998, for a review), and the causal emphasis of the conceptual model with which the discussion began collectively argue for a diathesis-stress conception of the syndrome. And, as foregoing comments make clear, task and setting variables and the mechanisms through which they influence symptom expression are as important to the phenomenon as are neurobiological predisposing causes. This has significant implications for assessment strategies employed in diagnosis and evaluation of treatment-outcome. Specifically, it suggests that theory-based experimental manipulations of task and setting variables designed to impose challenge on hypothesized core features of the disorder are more likely to yield insights into the causal mechanisms governing behavioral organization in affected children than strategies emphasizing static identification of diagnostic correlates. It is hoped that such an approach will accelerate the discovery of increasingly effective assessment and intervention strategies.

Incoherence of neuroimaging studies of attention deficit/hyperactivity disorder

Neuroimaging studies have been conducted with increasing frequency in recent years in attempts to identify structural and functional abnormalities in the brains of persons with attention deficit/hyperactivity disorder. Although the results of these studies are frequently cited in support of a biologic etiology for this disorder, inconsistencies among studies raise questions about the reliability of the findings. The present review shows that no specific abnormality in brain structure or function has been convincingly demonstrated by neuroimaging studies. Implications regarding stimulant treatment for attention deficit/hyperactivity disorder are discussed.

Long-term effects of postnatal amphetamine treatment on striatal protein kinase A activity, dopamine D(1)-like and D(2)-like binding sites, and dopamine content

The purpose of the present study was to determine whether exposure to amphetamine during the preweanling period would alter dopaminergic functioning in the dorsal striatum of adult rats. In three experiments, we assessed the effects of repeated amphetamine treatment on striatal protein kinase A (PKA) activity, dopamine (DA) D(1)-like and D(2)-like binding sites, and DA content. Rats were pretreated with saline or amphetamine (2.5 mg/kg, ip) for 7 consecutive days starting on postnatal day (PD) 11. At PD 90, rats were killed and their dorsal striata (i.e., caudate-putamen) were removed and frozen until time of assay. Amphetamine pretreatment produced long-term reductions in both striatal PKA activity and DA content. Early amphetamine exposure also resulted in an upregulation of D(2)-like binding sites, while leaving D(1)-like binding sites unaffected. It is likely that the upregulation of D(2)-like binding sites was stimulated by the persistent decline in striatal DA levels. Although speculative, it is possible that excess striatal D(2)-like receptors were responsible for inhibiting PKA activity through actions on the cAMP signal transduction pathway. The behavioral relevance of these amphetamine-induced neurochemical changes has not yet be determined.

Current concepts and controversies in the diagnosis and treatment of attention deficit hyperactivity disorder

Concerns about possible over-diagnosis and over-treatment of attention deficit hyperactivity disorder (ADHD) have been prominent in media reports, as have various competing claims about the safety and efficacy of the various treatments for ADHD. Drawing upon the results of the recent National Institutes of Health Consensus Conference, this paper reviews the evidence concerning these controversial areas. Although there do appear to be pockets of over-prescribing in selected communities, the best available evidence suggests that across the United States substantial underdiagnosis continues to occur, and only 50% of all children with ADHD are being treated with stimulant medications. Among those who are treated with stimulant medications, inadequate treatment is quite common. Substantial evidence suggests that for ADHD symptoms, stimulants are more effective than behavioral therapies in head-to-head comparisons. Combined medication and behavioral treatments do not offer any meaningful advantages over medication treatments alone for ADHD symptoms. For other areas of functioning, however (social skills, academic performance, etc.), combined treatments appear to offer some modest advantages over single treatment approaches. Although research findings show that ADHD can indeed be rigorously and reliably diagnosed under optimal conditions, and that carefully delivered treatments can yield substantial benefits, such best practices do not appear to be taking place in the real world. Thus, although the above controversies are facing some resolution in principal, in practice much remains to be done.

Stimulant medication for the child with attention-deficit/hyperactivity disorder

Stimulant medications have been used to manage the associated symptoms of ADHD including inattention, developmentally inappropriate levels of activity, distractibility, and impulsivity. To date, clinical trials clearly have established the efficacy of the stimulants on the core symptoms of ADHD and associated aggression. Although the stimulants improve classroom productivity and behavior, few data have demonstrated the effectiveness of the stimulants on academic achievement. Finally, there has been a paucity of data on the long-term efficacy and safety of stimulants. Recommendations are made for future research studies that examine the integration of stimulant medication with other psychosocial therapies, particularly behavior management.

The extent of drug therapy for attention deficit-hyperactivity disorder among children in public schools

OBJECTIVES

The purpose of this study was to determine the extent of medication use for attention deficit-hyperactivity disorder (ADHD) in southeastern Virginia.

METHODS

Students enrolled in grades 2 through 5 in school districts in city A (n = 5767 students) and city B (n = 23,967 students) were included. Nurses recorded students who received ADHD medication in school.

RESULTS

The proportion of students receiving ADHD medication was similar in both cities (8% and 10%) and was 2 to 3 times as high as the expected rate of ADHD. Receipt of drug therapy was associated with social and educational characteristics. Medication was used by 3 times as many boys as girls and by twice as many Whites as Blacks. Medication use increased with years in school, and by fifth grade 18% to 20% of White boys were receiving ADHD medication. Being young for one's grade was positively associated with medication use (P < .01). The prevalence of ADHD was 12% in district A, 63% in district B.

CONCLUSIONS

These findings suggest that criteria for diagnosis of ADHD vary substantially across US populations, with potential overdiagnosis and overtreatment of ADHD in some groups of children.

Do typical clinical doses of methylphenidate cause tics in children treated for attention-deficit hyperactivity disorder?

OBJECTIVE

To determine whether typical clinical doses of methylphenidate (MPH) cause tics or exacerbate preexisting mild to moderate tics.

METHOD

Ninety-one children with attention-deficit hyperactivity disorder, with and without comorbid tics (excluding severe tics and Tourette's syndrome), were randomly assigned to receive MPH or a placebo in a 1-year prospective study. The target dose was titrated to balance behavior change and side effects. Parents and teachers were the observers.

RESULTS

Crossover from the placebo to MPH was common because of poor behavioral response. One MPH-treated subject dropped out; the final MPH group had 72 subjects; the placebo group, 18. The average dose of MPH was 0.5 mg/kg twice daily. Clinically significant tics developed in 19.6% of the subjects without preexisting tics receiving MPH and in 16.7% of those receiving the placebo (Fisher exact test, p = .59, not significant; relative risk = 1.17, confidence interval = 0.31-4.40). Deterioration of tics was observed in 33% of subjects with preexisting tics receiving MPH and in 33% of those receiving the placebo (Fisher exact test, p = .70, not significant; relative risk = 1.0, confidence interval = 0.40-1.85).

CONCLUSIONS

Doses of MPH based on the typical clinical titration procedure did not produce significantly more tics than the placebo in children with or without preexisting (mild to moderate) tics.

Population pharmacokinetics of methylphenidate in children with attention-deficit hyperactivity disorder

Sources of individual variation in plasma methylphenidate (MP) concentrations during usual clinical use are not established. This was evaluated in a series of patients receiving clinical treatment with MP. A single plasma MP concentration was determined in each of 273 children and adolescents ages 5 to 18 years (mean: 11.1 years) who were clinically good responders to MP for the treatment of attention-deficit hyperactivity disorder. MP was given on a twice-daily schedule (mean dose: 25 mg/day) in 40% of patients and three times daily (mean dose: 39.3 mg/day) in 60%. A nonlinear regression model was applied to estimate overall population values of MP clearance and elimination half-life (t1/2), assuming a one-component model with first-order absorption and elimination, and further assuming that clearance is linearly related to body weight. The model incorporated each patient's dosage size and schedule, body weight, and time of the plasma sample. Iterated solutions of best fit were: t1/2, 4.5 hours (95% confidence interval [CI]: 3.1-8.1 hours), and apparent clearance, 90.7 ml/min/kg (95% CI: 74.6-106.7 ml/min/kg). The model explained 43% of the overall variance in MP concentrations (r2 = 0.43, p < .001). In a small subsample (N = 16), a second plasma sample was drawn at the same time of day and at the same dose; the correlation between the two concentration values was 0.83. The relatively noninvasive approach used in this study allows the assessment of pharmacokinetic properties of medications under conditions of appropriate clinical use in special populations such as children, adolescents, and the elderly.

Attention deficit hyperactivity disorder: anxiety phenomena in children treated with psychostimulant medication for 6 months or more

OBJECTIVE

The intermediate- to long-term use of psychostimulant medication has unclear benefits on the core symptoms of attention deficit hyperactivity disorder (ADHD) and delayed onset affective symptom side effects which can mimic these core ADHD symptoms. 'ADHD and anxiety' has also been associated with a poor response to short-term psychostimulant medication treatment. In addition, it is unclear whether 'ADHD and anxiety' should be defined from the child's and/or the parent's perspective. We propose that anxiety will be increased in children with ADHD who are treated with psychostimulant medication in the intermediate- to long-term who are identified by clinicians as poor responders.

METHOD

Twenty children with ADHD who were medicated for 6 months or more and who had ongoing core symptoms of ADHD were compared to 20 age- and IQ-matched children with ADHD who were medication-naïve. Chi-squared tests were performed on the categorical dependent variables and independent t-tests on the dependent continuous variables.

RESULTS

Anxiety is significantly increased in children with ADHD treated with psychostimulant medication in the intermediate- to long-term who are noted by clinicians to have ongoing core symptoms of ADHD. This statistically significant finding is evident with both categorical and dimensional measures of anxiety from the child's perspective.

CONCLUSIONS

The recognition of anxiety and its management in children with ADHD is generally poorly understood. In this particular group of children with ADHD, anxiety may be a side effect of intermediate- to long-term psychostimulant medication and/or a potential marker for a poor response to intermediate- to long-term psychostimulant medication treatment.

Stimulant medications

OBJECTIVE

To review the short- and long-term safety and efficacy of stimulants for the treatment of children with attention-deficit/hyperactivity disorder (ADHD).

METHOD

A Medline search was conducted for both randomized controlled trials and reviews to determine the efficacy and safety of stimulant drugs for treating children with ADHD. Information was obtained on adverse events associated with their use, including their impact on height and weight gain during childhood. Animal data were reviewed for information on tolerance, sensitization, and the impact of high-dose stimulant effects on neurons and on the development of hepatic tumors. Human data on dopamine transporter occupancy by stimulants were also included.

RESULTS

Stimulant treatment studies show robust short-term efficacy and a good safety profile. Longer-term studies are few in number but have produced no conclusive evidence that careful therapeutic use of these medications is harmful.

CONCLUSION

Current evidence indicates that stimulants show efficacy and safety in studies lasting up to 24 months.

Response to methylphenidate in children with ADHD and comorbid anxiety

OBJECTIVE

To determine whether comorbid anxiety alters response to methylphenidate (MPH) in children with attention-deficit hyperactivity disorder (ADHD).

METHOD

Ninety-one children with ADHD were assessed for anxiety. Children were randomly assigned to receive MPH or placebo, titrated to a dose of 0.7 mg/kg, while side effects were minimized. Measures of side effects and behavioral response were obtained from parents and teachers before treatment, after titration to optimal dose, and after 4 months of treatment. These measures, dose of drug, and rate of adherence to assigned medication assignment were compared for nonanxious (ADHD- ANX) and anxious ADHD children (ADHD+ ANX).

RESULTS

Rates of adherence to original medication assignment did not differ between the groups. ADHD+ ANX on both MPH and placebo titrated to a lower dose at the end of titration, although the dose of drug did not differ among the groups after 4 months of treatment. No differential response to MPH between ADHD+ ANX and ADHD- ANX was noted at end-titration or at 4 months on any side effect or behavioral measures.

CONCLUSIONS

Comorbid anxiety does not appear to influence development of side effects or behavioral response to MPH when dose is titrated as in standard clinical practice.

Pharmacotherapy of adolescent attention deficit hyperactivity disorder: challenges, choices and caveats

A recent increase in stimulant treatment of adolescents with attention deficit hyperactivity disorder (ADHD) has been documented. Challenges in treating adolescent ADHD with methylphenidate or dextroamphetamine include compliance with frequent dosing, abuse potential and wear-off or rebound effects. Co-morbid anxiety, occurring in at least 30 percent of ADHD youths, is associated with lower rate of response to stimulants. The effective alternatives, tricyclic antidepressants or pemoline, are each associated with rare but serious toxicity. Bupropion has recently proven effective in controlled trials. Other noradrenergic or dopamine-enhancing agents such as venlafaxine and nicotine show some benefit in open trials. The need for more options in pharmacotherapy of ADHD is evidenced by rapid adoption in clinical practice of alternative and adjunctive medication despite lack of controlled research on efficacy and safety. The indications for long-term stimulant treatment of ADHD present some controversy, and highlight a need for more research on safety and efficacy through the lifespan. Thresholds for diagnosis are much lower with DSM than with ICD, and thresholds for treatment are contentious, given the performance-enhancing effects of stimulants in normal students. The endpoint for treatment is unclear, as stimulants are also effective in adult ADHD. Based on short- and intermediate-term studies to date, stimulant medication is clearly more efficacious than cognitive and behavioral strategies for the symptoms of ADHD. Longer term research is needed to determine whether sustained stimulant therapy will reduce the adverse emotional, behavioral and academic consequences of inattention and impulsivity in adolescents and adults.

Attention deficit hyperactivity disorder, CNS stimulants and sport

Attention deficit hyperactivity disorder (ADHD) affects 1 to 10% of children and is characterised by a persistent pattern of inattention and/or hyperactivity/impulsivity. Over one-half of children with ADHD have associated conditions, including learning disabilities, conduct disorders, poor coordination, depression, anxiety, obsessive-compulsive disorders and bipolar disorders. CNS stimulant medication used in the management of ADHD is not permitted for use in competition by the International Olympic Committee (IOC) and this poses a problem for the physicians of patients with ADHD. On the one hand, attention and concentration are improved by stimulant medication and fine motor coordination and balance are improved after methylphenidate administration, but these therapeutic and sport-related benefits are not available to the athlete with ADHD who wishes to compete under IOC rules. It has been suggested that treatment with methylphenidate may be suitable for athletes with ADHD, as cessation of therapy 24 hours before competition is usually adequate to allow drug clearance which should avoid a positive result being returned on drug testing. More research is needed to establish whether stimulant medication for athletes with ADHD provides an unfair advantage in competition.

Clinical and treatment characteristics of children with attention-deficit/hyperactivity disorder in psychiatric practice

OBJECTIVE

To capture information about the clinical characteristics of, and treatments for, children with attention-deficit/hyperactivity disorder (ADHD) in psychiatric practice.

METHOD

A mailed, self-administered questionnaire was sent to 81 practicing psychiatrists for them to complete on the next three consecutive patients aged 14 years and younger with ADHD seen during the 12-day study period. Information collected included the sociodemographic, clinical, and treatment characteristics of sampled patients.

RESULTS

Patients in the study were predominantly white (85%), male (78%), and between 10 and 14 years old (58%). The most common ADHD subtype was combined/predominantly hyperactive (86%); 31% had no other comorbidity. Ninety-seven percent were receiving medications, with 49% receiving two or more. The single most common medication reported was methylphenidate (51% of patients) followed by clonidine (20%). Psychotropics other than psychostimulants were used in a majority of patients (55%).

CONCLUSIONS

Psychiatrists, and child and adolescent psychiatrists in particular, see a more severely impaired and complex group of patients than would be expected of primary care providers. The treatment patterns of psychiatrists for these patients do not reflect the simpler treatments usually studied in clinical trials.

Evaluating medication response in ADHD: cognitive, behavioral, and single-subject methodology

Although evidence supports the use of double-blind placebo medication trials to evaluate methylphenidate (MPH) effects on the core behavioral symptoms of attention-deficit/hyperactivity disorder (ADHD), few studies have demonstrated their utility in examining MPH effects on the cognitive deficits associated with ADHD. This article presents a technique for evaluating behavioral and cognitive dose-response relationships at the single-subject level of analysis. Case study results and multivariate analyses suggest that systematic evaluation of behavioral and cognitive MPH dose-response relationships could lead to more accurate MPH titration and greater long-term multimodal treatment efficacy.

Methylphenidate versus dexamphetamine in children with attention deficit hyperactivity disorder: A double-blind, crossover trial

OBJECTIVE

To compare methylphenidate (MPH) and dexamphetamine (DEX) in a sample of children with attention deficit hyperactivity disorder (ADHD).

METHOD

A total of 125 children with ADHD received both MPH (0.3 mg/kg twice daily) and DEX (0.15 mg/kg twice daily) for 2 weeks a double-blind, crossover study. Outcome measures were Conners' Parent Rating Scale-Revised, Conners' Teacher Rating Scale-Revised, a Parent Global Perceptions questionnaire, the Continuous Performance Test, and the Barkley Side Effects Rating Scale.

RESULTS

There were significant group mean improvements from baseline score on all measures for both stimulants. On the Conners' Teacher Rating Scale-Revised, response was greater on MPH than DEX on the conduct problems and hyperactivity factors, as well as on the hyperactivity index. On the Conners' Parent Rating Scale-Revised, anxiety was the only factor to differ significantly, in favor of MPH. Parents rated 73% of subjects as globally improved on MPH and 69% improved on DEX, compared with baseline. Overall, 46% of parents chose MPH as the preferred drug, compared with 37% who chose DEX. On the Continuous Performance Test, there was no difference in the number of correct responses or errors between the two drugs.

CONCLUSIONS

Most children with ADHD improve significantly on both MPH and DEX. There was a slight advantage to MPH on most measures.

Behavioral, situational, and temporal effects of treatment of ADHD with methylphenidate

OBJECTIVE

To determine the behavioral, situational, and temporal effects of 4 months of methylphenidate (MPH) treatment for attention-deficit hyperactivity disorder (ADHD).

METHOD

Ninety-one children with ADHD were randomly assigned to receive either MPH (titrated to a target dose of 0.7 mg/kg twice a day) or a placebo. Treatment effects were investigated with measures sensitive to various behaviors (core and associated symptoms), situations (home and school), time periods (morning and afternoon, after reaching the target dose, and after 4 months of treatment), and side effects.

RESULTS

MPH treatment improved symptoms of ADHD and oppositional behavior at school, both in the morning and afternoon, but not at home. Side effects (increase in physiological and effective symptoms, lack of weight gain) were significantly more frequent with MPH than with placebo treatment. Benefit was evident after titration, but the onset of some side effects was delayed. Side effects were reported by parents but not by teachers.

CONCLUSIONS

Positive effects of MPH on behavior are evident in the classroom, but with MPH given twice daily, parents do not report that MPH improves behavior at home. Greater impact on home behavior may require three times daily MPH and combined treatments.

Diagnostic comorbidity in hospitalized adolescents with conduct disorder

We compared the diagnostic comorbidity of DSM-III-R axis I and axis II disorders in a sample of hospitalized adolescents with conduct disorder (CD) and a comparison group of hospitalized adolescents without conduct disorder (non-CD). Of 138 consecutively evaluated adolescents, 76 patients met criteria for CD and 62 did not. On axis I, CD was significantly comorbid with attention-deficit hyperactivity disorder (ADHD) and substance use disorders (SUDs). None of the personality disorders assessed showed differential association with CD. The comorbid relationships found within this sample suggest a strong association between CD, ADHD, and SUD in hospitalized teenagers. This finding underscores the clinical importance of conducting a thorough developmental assessment and, when indicated, of treating ADHD and SUD in conduct-disordered adolescents.

Medication treatment strategies in the MTA Study: relevance to clinicians and researchers

OBJECTIVE

Clinicians have difficulty applying drug research findings to clinical practice, because research protocols use methods different from those used in daily office practice settings.

METHOD

To design a medication protocol for a multisite clinical trial involving 576 children with attention-deficit hyperactivity disorder (ADHD) while maintaining relevance to clinical practice, investigators from the NIMH Collaborative Multisite Multimodal Treatment Study of Children with Attention-Deficit/Hyperactivity Disorder (MTA study) developed novel medication strategies. These were designed to work either in a monomodal or multimodal format and to ensure standard approaches are used across diverse sites. Each child randomized to medication (projected N = 288) is individually titrated to his or her "best" methylphenidate dose and has individual ADHD symptoms monitored. Decision rules were developed to guide "best dose" selection, dose changes, medication changes, the management of side effects, and integration with psychosocial treatments.

CONCLUSIONS

The MTA study uses a controlled method to standardize the identification of each child's "best" methylphenidate dose in a national, multisite cooperative treatment program. Although the titration protocol is complex, the study's individual dosing approach and algorithms for openly managing ADHD children's medication over time will be of interest to clinicians in office practice.

National trends in the use of stimulant medication for attention deficit hyperactivity disorder

OBJECTIVE

To document the use of stimulant medication in the different states and territories of Australia in 1993 and trends in use of stimulant medication in Western Australia and New South Wales from 1988 to 1993.

METHODOLOGY

Health authorities in the states and territories of Australia were contacted and requested to provided data on total numbers, patient gender, date of birth, postcode and type of stimulant medication prescribed to estimate the prevalence of use of stimulant medication in Australia.

RESULTS

Despite variation in the data obtained from each health authority there is a significant difference in the rates of use of stimulant medication between states and territories in Australia, and a significant increase in use between 1988 and 1993 in Western Australia and New South Wales.

CONCLUSIONS

These trends should continue to be closely monitored and the possibility of establishing national prescription guidelines considered.

Some reasons for concern about attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is not a disease. The symptoms of its three dimensions (activity, attention and impulsivity) are normally distributed in the population, with an arbitrary level of symptoms being designated pathological. The presence of the ADHD cluster is never grounds for any positive diagnosis; it is an indication for further assessment. Positive response to stimulants is not specific to the ADHD population, and is no way diagnostic.

NIMH collaborative multisite multimodal treatment study of children with ADHD: I. Background and rationale

OBJECTIVE

The National Institute of Mental Health's recently initiated 5-year, multisite, multimodal treatment study of children with attention-deficit hyperactivity disorder (MTA) is the first major clinical trial in its history focused on a childhood mental disorder. This article reviews the major scientific and clinical bases for initiating the MTA.

METHOD

A selective review of the literature is presented in the service of describing the estimated prevalence of ADHD among children and adolescents, its core clinical features, evidence concerning psychopharmacological and psychosocial treatment effects, and related research issues and trends leading to the development of the MTA.

RESULTS

Despite decades of treatment research and clinical practice, there is an insufficient basis for answering the following manifold question: under what circumstances and with what child characteristics (comorbid conditions, gender, family history, home environment, age, nutritional/metabolic status, etc.) do which treatments or combinations of treatment (stimulants, behavior therapy, parent training, school-based intervention) have what impacts (improvement, stasis, deterioration) on what domains of child functioning (cognitive, academic, behavioral, neurophysiological, neuropsychological, peer relations, family relations), for how long (short versus long term), to what extent (effect sizes, normal versus pathological range), and why (processes underlying change)?

CONCLUSIONS

The important scientific, clinical, and public health issues nested within this manifold question provide both the impetus and scaffolding for the MTA.

Methylphenidate and cognitive flexibility: dissociated dose effects in hyperactive children

A randomized, double-blind, placebo-controlled trial was conducted to assess the acute effects of placebo and three doses of methylphenidate (MPH) (0.3, 0.6, 0.9 mg/kg) on cognitive flexibility and overt behavior in 28 children with a confirmed diagnosis of attention deficit-hyperactivity disorder. Two underlying cognitive processes (response inhibition and response reengagement) were assessed by measuring the probability and speed with which subjects could inhibit responses to a primary task (forced-choice letter discrimination) and immediately execute a response to a secondary task (simple reaction time) when given a signal to do so. Results indicated that MPH enhanced cognitive flexibility, although the high dose was less effective than lower doses in enhancing response inhibition. Dissociations of dose effects on cognitive function and behavior were demonstrated: Dose-response functions for changes in behavior were linear, whereas the function for response inhibition was U-shaped. Findings argue against the typical clinical practice of determining the response to stimulant treatment from a single measure such as parent report of child behavior.

Acute challenge ERP as a prognostic of stimulant therapy outcome in attention-deficit hyperactivity disorder

Thirty-five children were tested with an auditory oddball P300 paradigm both before and 2 hr after a single-dose trial of methylphenidate (MPH). A prediction of the long-term benefit of medication was then made based on the magnitude of the acute changes in P3b amplitude. Those with postdrug amplitude increases of at least 30% were predicted to respond favorably to stimulants. All children were followed-up at 6 months. The original MPH Challenge Test predictions (based on acute post drug P3b amplitude changes) were then compared with the clinicians' evaluations of outcome. The MPH challenge classification accurately predicted outcome in 81% of cases.

Prescribing practices of outpatient child psychiatrists

OBJECTIVE

This study was designed to assess outpatient child psychiatrists' prescribing practices.

METHOD

Of 1,422 outpatients in two public, university affiliated settings in New York and Ohio, the charts of 146 medicated and 126 nonmedicated randomly selected patients were reviewed for demographic variables, DSM-III-R diagnoses, medications prescribed, and charted prescription rationales.

RESULTS

Fifteen percent of the 800 outpatients seen in a 1-month period in New York, and 19% of the 626 outpatients seen in a 1-year period in Ohio were prescribed medication. Patients medicated by clinic psychiatrists were significantly more likely than nonmedicated patients to be psychotic and to have been hospitalized previously, and significantly less likely to have adjustment disorder. Using standards employed by drug utilization review committees, medications were prescribed appropriately in approximately 90% of cases. Of concern, 65% of patients given antipsychotics in New York and 67% in Ohio were not psychotic; the primary target symptom in such cases was aggression.

CONCLUSIONS

Prescribing practices appeared to be appropriate, although the use of antipsychotic medications in nonpsychotic children is a concern for the field of child psychiatry. The strong similarity of practices in two independent and geographically remote sites suggests the findings are generalizable to providers in other public, university affiliated settings.