A randomised, double-blind, placebo-controlled trial of dexamphetamine in adults with attention deficit hyperactivity disorder

Epilepsy and Attention Deficit Hyperactivity Disorder: Connection, Chance, and Challenges

Comorbidities are common in children with epilepsy, with nearly half of the patients having at least one comorbidity. Attention deficit hyperactivity disorder (ADHD) is a psychiatric disorder characterized by hyperactivity and inattentiveness level disproportional to the child’s developmental stage. The burden of ADHD in children with epilepsy is high and can adversely affect the patients’ clinical outcomes, psychosocial aspects, and quality of life. Several hypotheses were proposed to explain the high burden of ADHD in childhood epilepsy; the well-established bidirectional connection and shared genetic/non-genetic factors between epilepsy and comorbid ADHD largely rule out the possibility of a chance in this association. Stimulants are effective in children with comorbid ADHD, and the current body of evidence supports their safety within the approved dose. Nonetheless, safety data should be further studied in randomized, double-blinded, placebo-controlled trials. Comorbid ADHD is still under-recognized in clinical practice. Early identification and management of comorbid ADHD are crucial to optimize the prognosis and reduce the risk of adverse long-term neurodevelopmental outcomes. The identification of the shared genetic background of epilepsy and ADHD can open the gate for tailoring treatment options for these patients through precision medicine.

Pharmacologic treatment of attention deficit hyperactivity disorder in adults: A systematic review and network meta-analysis

Background

Attention deficit hyperactivity disorder (ADHD) affects approximately 3% of adults globally. Many pharmacologic treatments options exist, yet the comparative benefits and harms of individual treatments are largely unknown. We performed a systematic review and network meta-analysis to assess the relative effects of individual pharmacologic treatments for adults with ADHD.

Methods

We searched English-language published and grey literature sources for randomized clinical trials (RCTs) involving pharmacologic treatment of ADHD in adults (December 2018). The primary outcome was clinical response; secondary outcomes were quality of life, executive function, driving behaviour, withdrawals due to adverse events, treatment discontinuation, serious adverse events, hospitalization, cardiovascular adverse events, and emergency department visits. Data were pooled via pair-wise meta-analyses and Bayesian network meta-analyses. Risk of bias was assessed by use of Cochrane’s Risk of Bias tool, and the certainty of the evidence was assessed by use of the GRADE framework.

Results

Eighty-one unique trials that reported at least one outcome of interest were included, most of which were at high or unclear risk of at least one important source of bias. Notably, only 5 RCTs were deemed at overall low risk of bias. Included pharmacotherapies were methylphenidate, atomoxetine, dexamfetamine, lisdexamfetamine, guanfacine, bupropion, mixed amphetamine salts, and modafinil. As a class, ADHD pharmacotherapy improved patient- and clinician-reported clinical response compared with placebo (range: 4 to 15 RCTs per outcome); however, these findings were not conserved when the analyses were restricted to studies at low risk of bias, and the certainty of the finding is very low. There were few differences among individual medications, although atomoxetine was associated with improved patient-reported clinical response and quality of life compared with placebo. There was no significant difference in the risk of serious adverse events or treatment discontinuation between ADHD pharmacotherapies and placebo; however, the proportion of participants who withdrew due to adverse events was significantly higher among participants who received any ADHD pharmacotherapy. Few RCTs reported on the occurrence of adverse events over a long treatment duration.

Conclusions

Overall, despite a class effect of improving clinical response relative to placebo, there were few differences among the individual ADHD pharmacotherapies, and most studies were at risk of at least one important source of bias. Furthermore, the certainty of the evidence was very low to low for all outcomes, and there was limited reporting of long-term adverse events. As such, the choice between ADHD pharmacotherapies may depend on individual patient considerations, and future studies should assess the long-term effects of individual pharmacotherapies on patient-important outcomes, including quality of life, in robust blinded RCTs.

Registration

PROSPERO no. CRD 42015026049

Safety of Treatments for ADHD in Adults: Pairwise and Network Meta-Analyses

OBJECTIVE

The aim of the study was to analyze evidence comparing the profile of drugs used to treat ADHD in adult patients.

METHOD

Systematic searches were conducted in electronic databases. Randomized, double-blind, parallel controlled trials that evaluated the safety of drugs in ADHD were included. The statistical analyses were conducted by pairwise meta-analyses and mixed treatment comparison (MTC).

RESULTS

Ten ( n = 3006) trials were included in the analyses. We observed statistical differences for the following outcomes: decreased appetite between atomoxetine and placebo (odds ratio [OR] = 0.15, 95% credibility interval [CrI] = [0.05, 0.38]) and extended-release mixed amphetamine salts and placebo (OR = 0.06, 95% CrI = [0.00, 0.51]); insomnia between atomoxetine and placebo (OR = 0.48, 95% CrI = [0.27, 0.88]) and extended-release mixed amphetamine salts and placebo (OR = 0.23, 95% CrI = [0.06, 0.76]); sleepiness between atomoxetine and methylphenidate OROS (OR = 0.24, 95% CrI = [0.06, 0.97]); and decreased libido between atomoxetine and placebo (OR = 0.28, 95% CrI = [0.08, 0.90]).

CONCLUSION

It was possible to generate evidence about the safety profile of different ADHD drugs.

Amphetamines for attention deficit hyperactivity disorder (ADHD) in adults

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset disorder characterised by inattention, hyperactivity, and impulsivity. ADHD can persist into adulthood and can affects individuals' social and occupational functioning, as well as their quality of life and health. ADHD is frequently associated with other mental disorders such as substance use disorders and anxiety and affective disorders. Amphetamines are used to treat adults with ADHD, but uncertainties about their efficacy and safety remain.

OBJECTIVES

To examine the efficacy and safety of amphetamines for adults with ADHD.

SEARCH METHODS

In August 2017, we searched CENTRAL, MEDLINE, Embase, PsycINFO, 10 other databases, and two trials registers, and we ran citation searches for included studies. We also contacted the corresponding authors of all included studies, other experts in the field, and the pharmaceutical company, Shire, and we searched the reference lists of retrieved studies and reviews for other published, unpublished, or ongoing studies. For each included study, we performed a citation search in Web of Science to identify any later studies that may have cited it.

SELECTION CRITERIA

We searched for randomised controlled trials comparing the efficacy of amphetamines (at any dose) for ADHD in adults aged 18 years and over against placebo or an active intervention.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data from each included study. We used the standardised mean difference (SMD) and the risk ratio (RR) to assess continuous and dichotomous outcomes, respectively. We conducted a stratified analysis to determine the influence of moderating variables. We assessed trials for risk of bias and drew a funnel plot to investigate the possibility of publication bias. We rated the quality of the evidence using the GRADE approach, which yielded high, moderate, low, or very low quality ratings based on evaluation of within-trial risk of bias, directness of evidence, heterogeneity of data; precision of effect estimates, and risk of publication bias.

MAIN RESULTS

We included 19 studies that investigated three types of amphetamines: dexamphetamine (10.2 mg/d to 21.8 mg/d), lisdexamfetamine (30 mg/d to 70 mg/d), and mixed amphetamine salts (MAS; 12.5 mg/d to 80 mg/d). These studies enrolled 2521 participants; most were middle-aged (35.3 years), Caucasian males (57.2%), with a combined type of ADHD (78.8%). Eighteen studies were conducted in the USA, and one study was conducted in both Canada and the USA. Ten were multi-site studies. All studies were placebo-controlled, and three also included an active comparator: guanfacine, modafinil, or paroxetine. Most studies had short-term follow-up and a mean study length of 5.3 weeks.We found no studies that had low risk of bias in all domains of the Cochrane 'Risk of bias' tool, mainly because amphetamines have powerful subjective effects that may reveal the assigned treatment, but also because we noted attrition bias, and because we could not rule out the possibility of a carry-over effect in studies that used a cross-over design.Sixteen studies were funded by the pharmaceutical industry, one study was publicly funded, and two studies did not report their funding sources.Amphetamines versus placeboSeverity of ADHD symptoms: we found low- to very low-quality evidence suggesting that amphetamines reduced the severity of ADHD symptoms as rated by clinicians (SMD -0.90, 95% confidence interval (CI) -1.04 to -0.75; 13 studies, 2028 participants) and patients (SMD -0.51, 95% CI -0.75 to -0.28; six studies, 120 participants).Retention: overall, we found low-quality evidence suggesting that amphetamines did not improve retention in treatment (risk ratio (RR) 1.06, 95% CI 0.99 to 1.13; 17 studies, 2323 participants).Adverse events: we found that amphetamines were associated with an increased proportion of patients who withdrew because of adverse events (RR 2.69, 95% CI 1.63 to 4.45; 17 studies, 2409 participants).Type of amphetamine: we found differences between amphetamines for the severity of ADHD symptoms as rated by clinicians. Both lisdexamfetamine (SMD -1.06, 95% CI -1.26 to -0.85; seven studies, 896 participants; low-quality evidence) and MAS (SMD -0.80, 95% CI -0.93 to -0.66; five studies, 1083 participants; low-quality evidence) reduced the severity of ADHD symptoms. In contrast, we found no evidence to suggest that dexamphetamine reduced the severity of ADHD symptoms (SMD -0.24, 95% CI -0.80 to 0.32; one study, 49 participants; very low-quality evidence). In addition, all amphetamines were efficacious in reducing the severity of ADHD symptoms as rated by patients (dexamphetamine: SMD -0.77, 95% CI -1.14 to -0.40; two studies, 35 participants; low-quality evidence; lisdexamfetamine: SMD -0.33, 95% CI -0.65 to -0.01; three studies, 67 participants; low-quality evidence; MAS: SMD -0.45, 95% CI -1.02 to 0.12; one study, 18 participants; very low-quality evidence).Dose at study completion: different doses of amphetamines did not appear to be associated with differences in efficacy.Type of drug-release formulation: we investigated immediate- and sustained-release formulations but found no differences between them for any outcome.Amphetamines versus other drugsWe found no evidence that amphetamines improved ADHD symptom severity compared to other drug interventions.

AUTHORS' CONCLUSIONS

Amphetamines improved the severity of ADHD symptoms, as assessed by clinicians or patients, in the short term but did not improve retention to treatment. Amphetamines were associated with higher attrition due to adverse events. The short duration of studies coupled with their restrictive inclusion criteria limits the external validity of these findings. Furthermore, none of the included studies had an overall low risk of bias. Overall, the evidence generated by this review is of low or very low quality.

Gender differences in adults with attention-deficit/hyperactivity disorder: A narrative review

Certain characteristics of attention-deficit/hyperactivity disorder (ADHD) in children have long been known to differ by gender. What has not been as widely studied is whether gender is similarly associated with ADHD differences in adults. In this review, the relation between gender and adult ADHD prevalence, persistence, impairment, comorbidity, cognitive functioning, and treatment response was examined across 73 studies. Although gender was related to several characteristics and correlates of adult ADHD, it appeared that many of these gender differences may be at least be partially attributed to methodological artifacts or social and cultural influences, rather than fundamental differences in the expression of ADHD in men and women. We highlight how understanding the nature of the relation between gender and ADHD across the lifespan is complicated by a number of methodological difficulties, and offer recommendations for how emerging research and clinical practice can better incorporate gender into the conceptualization of ADHD in adulthood.

Treatment of attention deficit hyperactivity disorder in adults

A number of medication and psychologic treatment options for adults with attention deficit hyperactivity disorder have become available during the past 5 years, while others are under investigation. This review describes the safety and effectiveness of the stimulants (i.e., methylphenidate and dexedrine), and particularly the newer long-acting stimulants (i.e., Concerta) and Adderall XR) in the treatment of this population. Some nonstimulant/nonantidepressants, particularly atomoxetine, have also been shown to improve attention deficit hyperactivity disorder symptoms. Combination treatment of stimulants and antidepressants require more study with regard to safety and efficacy. Psychosocial interventions (e.g., cognitive behavioral therapy, mindfulness training and cognitive remediation) can also benefit adults with attention deficit hyperactivity disorder. Cognitive behavioral therapy combined with medication is more effective than either intervention alone, especially for addressing the emotional and functional aspects of peoples lives and thus improving occupational, interpersonal and emotional outcomes.

Distinguishing comorbidity and successful management of adult ADHD

OBJECTIVE

Given high rates of comorbidity, lack of awareness and global acceptance, and varying guidelines for its management, adult ADHD may be an especially difficult condition to diagnose and treat. The objective of this review was to explore and characterize similarities and differences among comorbidities associated with adult ADHD.

METHOD

A review of the literature over the past 10 years was performed using Ovid.

RESULTS

A myriad of comorbid conditions such as impulse-control/personality, anxiety, mood, substance use, learning, and sleep disorders overlap with adult ADHD. Furthermore, a number of such conditions have symptoms that can mimic those of ADHD, including hyperactivity, impulsivity, inattention, and disruption of circadian rhythms, adding to the complexity of recognition and diagnosis of ADHD in adults. Extensive research shows that adults with ADHD appear to benefit from treatment with stimulant medications in similar ways as children, including significant improvements on driving performance. However, fear surrounding the abuse of stimulants is an important issue. Nevertheless, evidence suggests that children with ADHD who are treated with stimulant medication are less likely to develop a substance use disorder in adolescence and adulthood.

CONCLUSION

There are a wide range of comorbidities with adult ADHD with many having overlapping symptoms. The benefits observed with ADHD treatment, however, emphasize the importance of recognition and treatment of adult ADHD.

Comorbidity of migraine with ADHD

OBJECTIVE

The purpose of this study was to investigate how often drugs used to treat migraine and ADHD are prescribed to the same patients to assess, indirectly, the comorbidity of these disorders.

METHOD

We used data from the Norwegian prescription database for 2006, including the total Norwegian population (N = 4,640,219).

RESULTS

Antimigraine drugs were prescribed to 81,225 persons (1.75% of the total population), anti-ADHD drugs to 18,481 persons (0.40%), and 284 persons were prescribed both types of drugs. There was a positive and significant association between prescription of antimigraine and anti-ADHD drugs for all age groups between 20 and 50 for both genders, with odds ratios ranging from 1.76 to 2.81.

CONCLUSION

The prescription patterns for these drugs in adult patients indicate a comorbidity between migraine and ADHD.

The pharmacology and clinical outcomes of amphetamines to treat ADHD: does composition matter?

Attention-deficit hyperactivity disorder (ADHD) treatment options include pharmacological and nonpharmacological approaches. In North America, psychostimulants (amphetamine and methylphenidate) are considered first-line pharmacological treatments for patients (children, adolescents and adults) with ADHD. However, in the UK, National Institute for Health and Clinical Excellence (NICE) guidelines have placed short-acting d-amphetamine as a third-line treatment option due to a lack of contemporary, published clinical trials on its efficacy and the concerns from clinical and patient experts regarding the potential for increased abuse and/or misuse compared with methylphenidate. These guidelines do not account for some of the more recent amphetamine products that have been developed to alleviate some of these concerns, but that are not currently approved in the UK or other European countries. The purpose of this review is to describe the pharmacology and clinical efficacy of various amphetamine compositions, as well as to explore the apparent differences in these compositions and their associated risks and benefits. A PubMed literature search was conducted to investigate amphetamine pharmacology, clinical efficacy and safety and ADHD outcomes in the published literature from 1980 through March 2011. Search terms included the keywords 'ADHD' or 'ADD' or 'hyperkinetic disorder' and any of the following keywords combined with 'or': 'amphetamine', 'dexamphetamine', 'mixed amphetamine salts', 'lisdexamfetamine' and 'methamphetamine'. The search included English-language primary research articles and review articles but excluded editorial articles and commentaries. The literature search resulted in 330 articles. Pertinent articles relating to amphetamine pharmacology, compositions, clinical efficacy and safety, effectiveness and tolerability, ADHD outcomes and abuse liability were included in this review. The different delivery profiles of amphetamine compositions result in pharmacological and pharmacokinetic differences that contribute to varying effects in the clinical treatment of ADHD, ADHD outcomes and abuse liability. The efficacy and safety of amphetamine compositions for the treatment of ADHD have been demonstrated in clinical trials and meta-analyses, and the long-acting amphetamine compositions have been widely studied and found efficacious without increased adverse effects. Long-acting amphetamine compositions offer the obvious advantage of enhanced duration of action over short-acting amphetamine compositions, and lisdexamfetamine has been shown to have reduced abuse liability compared with short-acting amphetamine.

An update on the pharmacotherapy of attention-deficit/hyperactivity disorder in adults

Adults with attention-deficit/hyperactivity disorder (ADHD) are more frequently presenting for diagnosis and treatment. Medication is considered to be appropriate among available treatments for ADHD; however, the evidence supporting the use of pharmacotherapeutics for adults with ADHD remains less established. In this article, the effectiveness and dosing parameters of the various agents investigated for adult ADHD are reviewed. In adults with ADHD, short-term improvements in symptomatology have been documented through the use of stimulants and antidepressants. Studies suggest that methylphenidate and amphetamine maintained an immediate onset of action, whereas the ADHD response to the nonstimulants appeared to be delayed. At a group level, there appears to be some, albeit not entirely consistent, dose-dependent responses to amphetamine and methylphenidate. Generally speaking, variability in diagnostic criteria, dosing parameters and response rates between the various studies was considerable, and most studies were of a relatively short duration. The aggregate literature shows that the stimulants and catecholaminergic nonstimulants investigated had a clinically significant beneficial effect on treating ADHD in adults.

ADHD and female specific concerns: a review of the literature and clinical implications

ADHD was once thought of as a predominantly male disorder. While this may be true for ADHD in childhood, extant research suggests that the number of women with ADHD may be nearly equal to that of men with the disorder (Faraone et al., 2000). There is accumulating research which clearly indicates subtle but important sex differences exist in the symptom profile, neuropathology and clinical course of ADHD. Compared to males with ADHD, females with ADHD are more prone to have difficulties with inattentive symptoms than hyperactive and impulsive symptoms, and females often receive a diagnosis of ADHD significantly later than do males (Gaub & Carlson, 1997; Gershon, 2002a, 2002b). Emerging evidence suggests differences exist in the neuropathology of ADHD, and there are hormonal factors which may play an important role in understanding ADHD in females. Although research demonstrates females with ADHD differ from males in important ways, little research exists that evaluates differences in treatment response. Given the subtle but important differences in presentation and developmental course of ADHD, it is essential that both clinical practice and research be informed by awareness of these differences in order to better identify and promote improved quality of care to girls and women with ADHD.

Efficacy and tolerability of pharmacotherapies for attention-deficit hyperactivity disorder in adults

This review examines the evidence regarding the efficacy and tolerability of long- and short-acting stimulant medications, as well as the non-stimulant medications atomoxetine and bupropion in the treatment of adult attention-deficit hyperactivity disorder (ADHD). Effect sizes in adults appear to be of almost the same magnitude as in school-age children when robust doses are used. There are adequate data demonstrating short-term efficacy and safety of medication in ADHD during adulthood but long-term studies are lacking, particularly in view of concerns regarding cardiovascular adverse events. There is some evidence that stimulant medication can improve driving performance in adults with ADHD. The extent to which medication may improve academic, occupational and social functioning in adults with ADHD is unclear, and future research should investigate these outcomes. Medication treatment of adults with ADHD in sports is controversial. Both stimulant and non-stimulant medications seem to be well tolerated. Monitoring of pulse and blood pressure is recommended with these drugs because of their cardiovascular effects. There have been extremely rare case reports of sudden death in adults and children treated with stimulants and atomoxetine, but it is difficult to clearly establish causality. In view of reports of treatment-related suicide-related behaviour with atomoxetine, it is recommended that adults should be observed for agitation, irritability, suicidal thinking, self-harming or unusual behaviour, particularly in the first months of treatment, or after a change of dose. ADHD in adults continues to remain an under-recognized disorder in many parts of the world and there is a lack of specialist clinics for assessment and treatment of adult ADHD. Studies to date have failed to show efficacy of medications in the treatment of ADHD in the substance misuse population. There is little evidence so far to suggest an increased misuse of stimulants or diversion amongst substance misusers; however, data are insufficient to draw firm conclusions. Further work is necessary to evaluate effective treatments in subgroups such as the substance misuse population, those with multiple co-morbidities and different ADHD subtypes.

Age-grouped differences in adverse drug events from psychotropic medication

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Amphetamines for Attention Deficit Hyperactivity Disorder (ADHD) in adults

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is a childhood onset disorder that can persist into adulthood. Amphetamines are used to treat adult ADHD, but uncertainties persist about their efficacy and safety.

OBJECTIVES

To examine the efficacy and safety of amphetamines for adults with ADHD, as well as the influence of dose, drug type and release formulation type.

SEARCH STRATEGY

We searched CENTRAL, PubMed, EMBASE, CINAHL, PsycINFO, clinicaltrials.gov, UK Clinical Trials Gateway and references obtained from articles and experts in the field. We conducted the electronic searches on 25 February 2010.

SELECTION CRITERIA

Randomized controlled trials comparing the efficacy of amphetamine derivatives against placebo or an active intervention.

DATA COLLECTION AND ANALYSIS

Two authors extracted data from each included study. We used the standardized mean difference (SMD) and the risk ratio (RR) to assess continuous and dichotomous outcomes, respectively. We conducted a stratified analysis to determine the influence of moderating variables. We assessed the trials for risk of bias and drew a funnel plot to investigate the possibility of publication bias.

MAIN RESULTS

We included seven studies, which enrolled 1091 participants. All studies were placebo-controlled and three included an active comparator: guanfacine, modafinil and paroxetine. Most studies had short-term follow-up, with a mean study length of 8.1 weeks. Amphetamines improved ADHD symptom severity (SMD = -0.72; 95% CI -0.87 to -0.57) but did not improve retention in treatment overall and were associated with increased dropout due to adverse events (RR 3.03; 95% CI 1.52 to 6.05). The three amphetamine derivatives investigated (dextroamphetamine, lisdexamphetamine and mixed amphetamine salts (MAS)) were all efficacious for reducing ADHD symptoms, but MAS also increased retention in treatment. Different doses did not appear associated with differences in efficacy. We investigated immediate and sustained drug release formulations but found no difference between them on any outcome. When amphetamines were compared to other drug interventions, no differences were found. We did not find any study to be at low risk of bias overall, mainly because amphetamines have powerful subjective effects that may reveal the assigned treatment.

AUTHORS' CONCLUSIONS

Amphetamines improved short-term ADHD symptom severity. MAS also increased retention in treatment. Amphetamines were associated with higher attrition due to adverse events. The short study length and the restrictive inclusion criteria limit the external validity of these findings. Furthermore, the possibility that the results of the included studies were biased was high, which could have led to an overestimation of amphetamine efficacy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

What are the cognitive effects of stimulant medications? Emphasis on adults with attention-deficit/hyperactivity disorder (ADHD)

The relevant literature concerning cognitive effects of amphetamine and methylphenidate, was reviewed, with an emphasis on research conducted in adults diagnosed with attention-deficit/hyperactivity disorder. As first-line treatment for ADHD, stimulant drugs are well-known to improve attention and concentration. Yet, there is increasing evidence that (as with children and adolescents), they do not promote learning and academic achievement in adult college students with ADHD. A review of neuropsychological studies indicates that, although response latencies are reduced, performance of ADHD adults on tests of 'distractibility' and 'planning' is also not consistently improved by stimulants. Studies in non-ADHD adults suggest that stimulants do not promote acquisition of new information, might improve retention of previously acquired information, and facilitate memory consolidation, but may actually impair performance of tasks that require adaptation, flexibility and planning. It is still not clear if improvement only occurs when there is a baseline deficit. Stimulants may influence cognition by their effects on physiological arousal. Regardless, the evidence does not support the conclusion that stimulants are cognitive 'enhancers.'

Randomized controlled trial of dexamphetamine maintenance for the treatment of methamphetamine dependence

AIM

To investigate the safety and efficacy of once-daily supervised oral administration of sustained-release dexamphetamine in people dependent on methamphetamine.

DESIGN

Randomized, double-blind, placebo-controlled trial.

PARTICIPANTS

Forty-nine methamphetamine-dependent drug users from Drug and Alcohol Services South Australia (DASSA) clinics.

INTERVENTION

Participants were assigned randomly to receive up to 110 mg/day sustained-release dexamphetamine (n = 23) or placebo (n = 26) for a maximum of 12 weeks, with gradual reduction of the study medication over an additional 4 weeks. Medication was taken daily under pharmacist supervision.

MEASUREMENTS

Primary outcome measures included treatment retention, measures of methamphetamine consumption (self-report and hair analysis), degree of methamphetamine dependence and severity of methamphetamine withdrawal. Hair samples were analysed for methamphetamine using liquid chromatography-mass spectrometry.

FINDINGS

Treatment retention was significantly different between groups, with those who received dexamphetamine remaining in treatment for an average of 86.3 days compared with 48.6 days for those receiving placebo (P = 0.014). There were significant reductions in self-reported methamphetamine use between baseline and follow-up within each group (P < 0.0001), with a trend to a greater reduction among the dexamphetamine group (P = 0.086). Based on hair analysis, there was a significant decrease in methamphetamine concentration for both groups (P < 0.0001). At follow-up, degree of methamphetamine dependence was significantly lower in the dexamphetamine group (P = 0.042). Dexamphetamine maintenance was not associated with serious adverse events.

CONCLUSIONS

The results of this preliminary study have demonstrated that a maintenance pharmacotherapy programme of daily sustained-release amphetamine dispensing under pharmacist supervision is both feasible and safe. The increased retention in the dexamphetamine group, together with the general decreases in methamphetamine use, degree of dependence and withdrawal symptom severity, provide preliminary evidence that this may be an efficacious treatment option for methamphetamine dependence.

Pharmacotherapy of methamphetamine addiction: an update

Methamphetamine dependence is a serious public health problem worldwide for which there are no approved pharmacological treatments. Psychotherapy is still the mainstay of treatment; however, relapse rates are high. The search for effective pharmacological treatment has intensified in the last decade. This review will highlight progress in pharmacological interventions to treat methamphetamine dependence as well as explore new pharmacological targets. Published data from clinical trials for stimulant addiction were searched using PubMed and summarized, as well as highlights from a recent symposium on methamphetamine pharmacotherapy presented at the ISAM 2006 meeting, including interim analysis data from an ongoing D-amphetamine study in Australia. Early pilot data are encouraging for administering D-amphetamine and methylphenidate as treatment for heavy amphetamine users. Abilify at 15 mg/day dose increased amphetamine use in an outpatient pilot study. Sertraline, ondansetron, baclofen, tyrosine, and imipramine were ineffective in proof-of-concept studies. Development of pharmacotherapy for methamphetamine dependence is still in an early stage. Data suggesting D-amphetamine and methylphenidate as effective pharmacotherapy for methamphetamine addiction will need to be confirmed by larger trials. Preclinical data suggest that use of GVG, CB1 antagonist, and lobeline are also promising therapeutic strategies.

Attention-deficit/hyperactivity disorder in adults: evidence-based recommendations for management

Attention-deficit/hyperactivity disorder (ADHD) is associated with impairments in educational, occupational, neuropsychological, and social functioning in adults. Successful diagnosis and treatment of the disorder in adults can be a challenge because recent and integrative clinical guidelines are lacking and diagnostic criteria are based on making a retrospective diagnosis of childhood-onset ADHD. To develop evidence-based recommendations for the treatment of ADHD in adults, the scientific literature was reviewed, including primary clinical studies, meta-analyses, and available clinical guidelines. Studies show that stimulant therapy is highly effective and safe in the management of ADHD in adults, with similar response rates to those reported in children at doses that are equivalent on a mg/kg basis. Long-acting stimulants, such as OROS methylphenidate (OROS MPH, Concerta), dexmethylphenidate (d-MPH, Focalin), and mixed amphetamine salts extended release (MAS XR, Adderall XR), have durations of action of up to 10 to 12 hours, which permit once-daily dosing. For adults with ADHD who do not respond to stimulant therapy or who have a comorbid condition in which a stimulant is contraindicated, the nonstimulant atomoxetine (Strattera) may be an appropriate alternative. For many adults, cognitive-behavioral therapy in addition to pharmacotherapy may improve treatment response. Attention-deficit/hyperactivity disorder medications may increase blood pressure and heart rate in adults, so patients should be monitored.

ADHD in adults: a review of the literature

OBJECTIVE

ADHD presents significant challenges to adults. The current review's goals are (a) to critically examine the current state of knowledge regarding ADHD in adults and (b) to provide clinicians with practice-friendly information regarding assessment, diagnosis, and treatment.

METHOD

Searches of PsycINFO and Medline were conducted, and reference lists from articles and books were searched for additional relevant references.

RESULTS/CONCLUSION

A valid and reliable assessment should be comprehensive and include the use of symptom rating scales, a clinical interview, neuropsychological testing, and the corroboration of patient reports. Specific diagnostic criteria that are more sensitive and specific to adult functioning are needed. In treatment, pharmacological interventions have the most empirical support, with the stimulants methylphenidate and amphetamine and the antidepressants desipramine and atomoxetine having the highest efficacy rates. Scientific research on psychosocial treatments is lacking, with preliminary evidence supporting the combination of cognitive behavioral therapy and medication.

Comparative benefits and harms of competing medications for adults with attention-deficit hyperactivity disorder: a systematic review and indirect comparison meta-analysis

RATIONALE

Recommended medication prescribing hierarchies for adult attention-deficit hyperactivity disorder (ADHD) vary between different guideline committees. Few trials directly compare competing ADHD medications in adults and provide little insight for clinicians making treatment choices.

OBJECTIVE

The objective of this study was to assess comparative benefits and harms of competing medications for adult ADHD using indirect comparison meta-analysis.

MATERIALS AND METHODS

Eligible studies were English-language publications of randomized controlled trials comparing ADHD drugs to placebo. Data sources were electronic bibliographic databases, Drugs@FDA, manufacturer data, and reference lists. Two reviewers independently abstracted data on design, internal validity, population, and results. Benefits and harms were compared between drug types using indirect comparison meta-regression (ratio of relative risks).

RESULTS

Twenty-two placebo-controlled trials were included (n = 2,203). Relative benefit of clinical response for shorter-acting stimulants, primarily immediate release methylphenidate, was 3.26 times greater than for patients taking longer-acting stimulants (95% CI 2.03, 5.22) and 2.24 times greater than for patients taking longer-acting forms of bupropion (95% CI 1.23, 4.08). Immediate release methylphenidate is also the only drug shown to reduce ADHD symptoms in adults with substance abuse disorders. Neither non-stimulants nor longer-acting stimulants reduced adverse effects compared to shorter-acting stimulants. Key gaps in evidence were academic, occupational, social functioning, cardiovascular toxicity, and longer-term outcomes, influences of ADHD subtype and/or comorbidities, and misuse/diversion of the drugs.

CONCLUSIONS

Current best evidence supports using immediate release methylphenidate as first-line treatment for most adults with ADHD.

Treatment of adult ADHD: is current knowledge useful to clinicians?

Psychostimulant drugs have for decades been considered the cornerstone of ADHD treatment. Non-stimulant drugs have also been reported successful. However, many controlled studies exclude patients with comorbidities typical for patients seen in clinical setting. Many patients are also considered non-responders to medication. Current knowledge might not be directly useful to clinicians. The present article reviews the literature on pharmacological and psychotherapeutic treatment in adult ADHD emphasizing comorbidity and other clinically important factors, as well as ADHD specific outcomes. Thirty-three relevant studies of pharmacotherapy and three studies of psychotherapy were included. Most subjects had little current comorbidity, but some studies included subjects with substance use disorder. Significant effect of treatment on ADHD symptoms was found in most studies using pharmacotherapy and all studies of psychotherapy. Both positive and negative effects on comorbid anxiety and depression measures were reported. Pharmacotherapy did not seem to have effect on substance use disorder. Few pharmacotherapy studies conducted any long-term follow-up; two studies that did, found that most subjects had discontinued medication. A clear-cut dose-respons relationship was not substanciated. In conclusion, clinicians have good support for both pharmacological and psychotherapeutic treatment of ADHD in adults, but should take additional measures to deal with comorbidities as well as treatment adherence.

ADHD prevalence in adult outpatients with nonpsychotic psychiatric illnesses

OBJECTIVE

The prevalence of ADHD in the general adult population has been estimated to be about 4.4%. However, few studies exist in which the prevalence of ADHD in psychiatric adult outpatient samples has been estimated. These studies suggest that the prevalence is higher than in the general population. The objective of this study is to estimate the prevalence of ADHD in a psychiatric nonpsychotic adult outpatient sample and to compare this data with the prevalence of a group of nonclinical participants.

METHOD

The structured clinical interview Mini International Neuropsychiatric Interview (M.I.N.I.-Plus) was applied to 161 consecutive nonpsychotic psychiatric adult outpatients and to 149 healthy participants from the community. In addition, clinical rating scales were applied to measure the severity of general psychopathology such as mania, anxiety, depression, ADHD, and alcohol consumption in both groups.

RESULTS

The prevalence of ADHD in psychiatric nonpsychotic adult outpatients was 16.80% and 5.37% in nonclinical participants. In male psychiatric outpatients the prevalence of ADHD was 8.5% and for females was 21.6%.

CONCLUSION

This study concludes that a higher prevalence of ADHD exists in psychiatric nonpsychotic adult outpatients compared with nonclinical participants. In the psychiatric adult outpatients, females showed a higher prevalence of ADHD than males. Implications and limitations are discussed.

Treatment of cocaine dependent treatment seekers with adult ADHD: double-blind comparison of methylphenidate and placebo

The purpose of this double-blind 14-week trial was to compare the efficacy of sustained-release methylphenidate (MPH) to placebo (PBO) in treating adult attention deficit hyperactivity disorder (ADHD) symptoms in current cocaine dependent (CD) treatment seekers. The randomized sample consisted of 106 participants who were predominately male (83%) and 60% Caucasian, 14% Hispanic, 20% African-American and 6% other. All participants met DSM-IV criteria for ADHD and CD. There were no significant demographic differences between the two treatment groups. All participants received weekly individual cognitive behavioral therapy. There was no difference in retention rate based on treatment group (p=.91). The majority of the PBO group and the MPH group reported >30% improvement in their ADHD symptoms (55% versus 47%), with no significant difference between the two groups (p=.44). Using a combined outcome measure (>30% reduction in ADHD symptoms and CGI <3), the response rates were similar for both groups (28% PBO versus 30% MPH; p=.83). Longitudinal analyses of the urine toxicology data using generalized estimating equations, revealed a decrease in the probability of cocaine positive urine samples during the trial for the MPH group compared to the PBO group (p=.001). Further analysis suggested that for the MPH group, ADHD treatment responders, based on a semi structured clinical interview, were more likely to have a reduction in cocaine use compared to the non-ADHD responders. Although sustained-release MPH did not show superiority over PBO in treating ADHD symptoms, this trial provides some evidence that improvement in ADHD symptoms (clinician rated) among those patients receiving MPH, but not placebo, was associated with a reduction in cocaine use.

Evidence-based guidelines for management of attention-deficit/hyperactivity disorder in adolescents in transition to adult services and in adults: recommendations from the British Association for Psychopharmacology

Attention-deficit/hyperactivity disorder (ADHD) is an established diagnosis in children, associated with a large body of evidence on the benefits of treatment. Adolescents with ADHD are now leaving children's services often with no readily identifiable adult service to support them, which presents problems as local pharmacy regulations often preclude the prescription of stimulant drugs by general practitioners (GPs). In addition, adults with ADHD symptoms are now starting to present to primary care and psychiatry services requesting assessment and treatment. For these reasons, the British Association for Psychopharmacology (BAP) thought it timely to hold a consensus conference to review the body of evidence on childhood ADHD and the growing literature on ADHD in older age groups. Much of this initial guidance on managing ADHD in adolescents in transition and in adults is based on expert opinion derived from childhood evidence. We hope that, by the time these guidelines are updated, much evidence will be available to address the many directions for future research that are detailed here.

Pharmacological treatment of attention-deficit/hyperactivity disorder in adults

With increased awareness that attention-deficit/hyperactivity disorder (ADHD) can persist beyond childhood, pharmacological treatment options for adults have expanded. Short-acting stimulants continue to be the first-line approach, demonstrating clinical efficacy and few adverse events in well-controlled trials, with long-acting stimulants also showing promise. Atomoxetine has also been reported to improve ADHD symptoms and associated dysfunction, although longer-term, head-to-head studies with stimulants are needed. Several antidepressants (e.g., desipramine and buproprion) appear to be effective in the treatment of adult ADHD, but to a lesser extent than stimulants. Data are limited in evaluating the impact of combining pharmacological treatments for ADHD and comorbid conditions. This paper describes the safety and efficacy of medications for treating the core symptoms, psychosocial features and cognitive dysfunctions associated with adult ADHD.

Quantitative EEG analysis in dexamphetamine-responsive adults with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (AD/HD) is recognized as a disorder affecting children and adolescents and has more recently been documented to continue into adulthood in a proportion of patients. One of the common treatments for AD/HD is the use of stimulant medications. Numerous studies have examined the therapeutic effects of stimulant medications in children, adolescents and adults with the disorder, reporting improvements in attention, concentration, and hyperactive and impulsive behaviours. Several studies have also examined the effects of stimulants on the electroencephalograph (EEG) of children and adolescents with the disorder, but to date, there have been no studies examining the effects of stimulant medication on the EEG of adults with AD/HD. In the present study, we aimed to replicate previous EEG findings in adults with AD/HD relative to controls and to examine whether there was any change in this profile following treatment with dexamphetamine. The EEG was recorded at rest in an eyes-open condition from 50 adults diagnosed with AD/HD and assessed as good responders to treatment, both before and after treatment with dexamphetamine, and 50 control subjects. The pre-medication results are similar to those found in previous research that compared the EEGs of adults with AD/HD and control subjects. Following medication, there was a significant reduction in slow wave activity in the AD/HD group to levels similar to those in the control group. These results suggest that changes in brain function of good responders to dexamphetamine, as reflected in the EEG, may underlie the behavioural improvements observed in the clinical setting.

[Long-acting methylphenidate. An alternative medical therapy for adult patients with attention deficit hyperactivity disorder]

We report a 44-year-old female patient with attention deficit hyperactivity disorder (ADHD), combined subtype (DSM-IV: 314.01), who was treated with 0.5 mg of short-acting immediate-release methylphenidate/kg body weight given t.i.d. (total daily MPH IR dosage 45 mg). Under this medication, the patient reported significant reduction of symptoms. However, several times a day she experienced severe rebound phenomena with pronounced concentration disturbances, unrest, and dysphoric mood. After changing the medication to long-acting methylphenidate once daily (total daily OROS MPH dosage 54 mg), the rebound phenomena stopped, with equivalent beneficial clinical effects.

Adult ADHD and substance abuse: diagnostic and treatment issues

Attention deficit hyperactivity disorder (ADHD) is a neurobehavioral, developmental disorder most often diagnosed during childhood, marked by the core symptoms of inattention, hyperactivity, and impulsivity that results in social, academic, and occupational underachievement. Although the disorder has a prevalence of 3-9% in the general childhood population and 1-5% in the general adult population, it affects between 11 and 35% of "substance-abusing" adults, oftentimes complicating treatment response. The present review discusses diagnostic assessment issues, prevalence, comorbidity, pharmacotherapy, and psychological interventions in substance-abusing adults with ADHD.

Agonist-like, replacement pharmacotherapy for stimulant abuse and dependence

Stimulant abuse and dependence are disproportionately problematic due to the combination of legal and social issues added to the serious behavioural and biological features of the disorders. These problems are compounded by adverse consequences for families and society. Illegality and stigma multiply the consequences of use and difficulties in providing treatment. Specific behavioural interventions have been demonstrated as useful in treatment of substance use disorders (SUDs). Medications also have an important role in treatment. Effective agonist and antagonist pharmacotherapies as well as symptomatic treatments exist for opioid and nicotine dependence. Neither agonists nor antagonists have been approved as uniquely effective for treatment of stimulant abuse or dependence. Still, promising results are emerging for an agonist-like or 'replacement' strategy paralleling that for nicotine and opioid dependence. Supporting data have emerged from both preclinical and clinical research environments. There are scientific, clinical, social, and legal impediments to application of an agonist-like approach to stimulant abuse and dependence. Some resemble past and current concerns about opioid replacement. Others are unique to the stimulant agents, effects, and clinical features. Here, the authors consider (1) agonist and antagonist pharmacotherapy strategies; (2) preclinical research, including methodological approaches, opioid and nicotine replacement, and agonists for stimulant dependence; (3) clinical reports with stimulant medications in cocaine dependence, and the amphetamine replacement strategy for amphetamine dependence; (4) application of agonist-like/replacement strategies, including clinical requirements and risks; and (5) directions for research.

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.

Efficacy of Stimulants in Adult ADHD

OBJECTIVE

To review the literature regarding the efficacy of stimulants to treat attention-deficit-hyperactivity disorder (ADHD) in adults.

DATA SOURCES

The relevant pharmaceutical manufacturers were contacted, and searches of MEDLINE (1966-December 2002) and the reference sections of each article obtained were performed using the key search terms: adult ADHD, stimulants, methylphenidate, amphetamines, and pemoline.

STUDY SELECTION AND DATA EXTRACTION

All English-language original studies identified from the data sources were evaluated and all information deemed relevant was included in the review.

DATA SYNTHESIS

Studies involving methylphenidate, amphetamines, and pemoline were identified. There was evidence for the efficacy of amphetamines from 5 studies (4 controlled, 1 open). Methylphenidate data from 6 controlled trials were conflicting. Three studies indicated efficacy; 2 studies failed to show efficacy, possibly due to methodologic reasons; and the results from 1 study were conflicting. The limited data from 1 controlled and 1 open study indicated that pemoline may be less effective than methylphenidate and amphetamines.

CONCLUSIONS

While the current limited data indicate that stimulants may be effective in adult ADHD, more data are required to confirm long-term efficacy.

A cognitive remediation programme for adults with Attention Deficit Hyperactivity Disorder

OBJECTIVE

This is the first systematic examination of the efficacy of a cognitive remediation programme (CRP) for management of adult Attention Deficit Hyperactivity Disorder (ADHD). The CRP was designed to target problems commonly associated with adult ADHD, namely, attention problems, poor motivation, poor organizational skills, impulsivity, reduced anger control and low self-esteem.

METHOD

In a randomized, controlled trial, a representative sample of adults with ADHD (some medicated, some not) were assigned to either a CRP (n = 22) or a waiting list control (n = 21). The CRP was delivered in an intensive format with eight two-hour, weekly sessions with support people who acted as coaches, and participant workbooks with homework exercises.

RESULTS

Participants who completed the CRP reported reduced ADHD symptomatology (effect size (d) = 1.4), improved organizational skills (d = 1.2) and reduced levels of anger (d = 0.5). Clinically significant improvements in ADHD symptomatology (d = 1.4) and organizational skills (d = 1.3) were maintained one year after the intervention.

CONCLUSIONS

These findings suggest that the CRP provides a practical way of enhancing daily functioning for adults with ADHD.

A review of the pharmacotherapy of adults with attention-deficit/hyperactivity disorder

OBJECTIVE

Despite the increasing recognition of attention deficit hyperactivity disorder (ADHD) in adults, the use of pharmacotherapeutics remains less established.

METHODS

A systematic review of the literature identified 15 studies (N = 435 subjects) of stimulants, and 22 studies of non-stimulant medications (N = 421 subjects) including antidepressants, antihypertensives, amino acids, and wake-promoting agents for the treatment of ADHD in adults.

RESULTS

Studies with stimulants and antidepressants demonstrated significant short-term improvement in ADHD symptoms compared to placebo in adults. Methylphenidate (MPH) and amphetamine had an immediate onset of action whereas the ADHD response to pemoline and antidepressants appeared delayed. The response to amphetamine and MPH appears to be dose-dependent. Controlled data on nicotonic and noradrenergic compounds appear promising. There was considerable variability in diagnostic criteria, dosing parameters, and response rates between the various studies.

CONCLUSIONS

Under controlled conditions, the aggregate literature shows that the stimulants and noradrenergic antidepressants had a clinically and statistically significant beneficial effect on treating ADHD in adults.

Attention-deficit/hyperactivity disorder

ADHD continues to be one of the most common psychiatric disorders in children and is recognized increasingly as a common psychiatric disorder in adults. Diagnosis of the disorder requires careful consideration of other psychiatric and medical disorders that may mimic symptoms of ADHD. Comorbid disorders are common in patients with ADHD and require careful attention. A recommended diagnostic evaluation for children and adults includes the completion of a psychiatric interview, rating scales from multiple informants, and often individually tailored psychologic testing. Pharmacologic treatment options include the first-line stimulant agents for adults and children and TCAs and atypical antidepressants as second-line agents. Behavioral interventions may help reduce ADHD symptoms and address comorbid conditions in children. Future research is needed to identify the optimal psychosocial treatment for adults with ADHD.

Present and future pharmacotherapeutic options for adult attention deficit/hyperactivity disorder

Attention deficit/hyperactivity disorder (ADHD) is often a lifelong condition. When untreated or undertreated, it appears to have a deleterious impact upon the daily functioning of the majority of adults that were diagnosed with this condition during childhood. Effective treatment, under the best circumstances, is multi-modal. The recent MTA study staged by the United States government confirmed the primary role of psychostimulants for children with this condition. The findings from this study have been generalised to adults that also have ADHD, particularly in cases where there is a well-defined longitudinal history dating back to early childhood. Psychostimulants remain a viable first-choice strategy for adults with ADHD. There are idiosyncratic differences in response to the various psychostimulants for any given individual with ADHD. Furthermore, the emergence of long-acting, once daily psychostimulant medications is likely to improve the calibre of care for adults with ADHD. A number of alternative pharmacotherapies have been studied, or are being developed, for adults with ADHD. These pharmacotherapies include antidepressant medications that affect dopaminergic and noradrenergic bioavailability, as well as cholinergic agents. In addition, agents that manipulate histaminergic and glutaminergic receptors are being studied as possible non-stimulant alternatives in the management of adult ADHD. More information is needed before any definitive statements can be made concerning the feasibility and utility of these non-stimulant medication approaches.

How high a dose of stimulant medication in adult attention deficit hyperactivity disorder?

OBJECTIVE

This paper examines clinical and neuroscientific evidence to address the question whether high doses of stimulant drugs offer additional advantages in the treatment of adult attention deficit hyperactivity disorder (ADHD) and at what cost. It attempts to arrive at a reasonable upper limit of dosage for clinical purposes.

METHOD

The study involves a selective review of the treatment studies of ADHD in children and adults and an examination of the pharmacokinetic and pharmacodynamic data on psychostimulants in humans and animals.

RESULTS AND CONCLUSIONS

The clinical and experimental data justify the use of chronic low-dose stimulant treatment of ADHD in adults, with the recommended upper limit of dose being 1 mg/kg for methylphenidate and 0.5 mg/kg for dexamphetamine. There is no empirical evidence of greater improvement with higher doses and any beneficial effect is likely to be compromised by the adverse effects, some of which can be very serious. The recommended doses should be exceeded only after careful consideration and objective documentation of beneficial and adverse consequences. Monitoring of drug levels in blood may be of some value for compliance or pharmacokinetic considerations, as there is a direct relationship between blood and brain levels as well as dopamine transporter occupancy. These recommendations are tentative and further clinical research is warranted.