Response inhibition and emotional cognition improved by atomoxetine in children and adolescents with ADHD: The ACTION randomized controlled trial

The effects of chronic administration of stimulant and non-stimulant medications on executive functions in ADHD: A systematic review and meta-analysis

Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with executive function deficits that are improved with medications. However, meta-analyses of stimulant effects on cognition have mostly tested single-dose effects, and there is no meta-analysis of non-stimulant effects. This systematic review and meta-analysis tested the clinically more relevant longer-term effects of Methylphenidate (20 studies; minimum 1 week) and Atomoxetine (8 studies; minimum 3 weeks) on reaction time, attention, inhibition, and working memory, searching papers on PubMed, Embase, Ovid MEDLINE, and PsycINFO. The meta-analysis of 18 studies in 1667 subjects showed that methylphenidate was superior to placebo in all cognitive domains with small to medium effect sizes (Hedges g of 0.34-0.59). The meta-analysis of atomoxetine included 7 studies in 829 subjects and showed no effects in working memory, but superior effects in the other domains with medium to large effect sizes (Hedge's g of 0.36-0.64). Meta-regression analysis showed no drug differences on cognitive effects. The meta-analyses show for the first time that chronic Methylphenidate and Atomoxetine have comparable effects of improving executive functions in people with ADHD.

Treating Executive Function in Youth With Attention Deficit Hyperactivity Disorder: A Review of Pharmacological and Non-Pharmacological Interventions

INTRODUCTION

Executive function (EF) deficits are common in youth with ADHD and pose significant functional impairments. The extent and effect of interventions addressing EF in youth with ADHD remain unclear.

METHODS

We conducted a systematic literature review using PRISMA guidelines. Included studies were randomized controlled trials of interventions to treat EF in youth with ADHD.

RESULTS

Our search returned 136 studies representing 11,443 study participants. We identified six intervention categories: nonstimulant pharmacological (N = 3,576 participants), neurological (N = 1,935), psychological (N = 2,387), digital (N = 2,416), physiological (N = 680), and combination (N = 366). The bulk of the evidence supported pharmacological interventions as most effective in mitigating EF, followed by psychological and digital interventions.

CONCLUSION

A breadth of treatments exists for EF in youth with ADHD. Pharmacological, psychotherapeutic, and digital interventions had the most favorable, replicable outcomes. A lack of outcome standardization across studies limited treatment comparison. More data on the persistence of intervention effects are necessary.

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

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

Brainmarker-I Differentially Predicts Remission to Various Attention-Deficit/Hyperactivity Disorder Treatments: A Discovery, Transfer, and Blinded Validation Study

BACKGROUND

Attention-deficit/hyperactivity disorder is characterized by neurobiological heterogeneity, possibly explaining why not all patients benefit from a given treatment. As a means to select the right treatment (stratification), biomarkers may aid in personalizing treatment prescription, thereby increasing remission rates.

METHODS

The biomarker in this study was developed in a heterogeneous clinical sample (N = 4249) and first applied to two large transfer datasets, a priori stratifying young males (<18 years) with a higher individual alpha peak frequency (iAPF) to methylphenidate (N = 336) and those with a lower iAPF to multimodal neurofeedback complemented with sleep coaching (N = 136). Blinded, out-of-sample validations were conducted in two independent samples. In addition, the association between iAPF and response to guanfacine and atomoxetine was explored.

RESULTS

Retrospective stratification in the transfer datasets resulted in a predicted gain in normalized remission of 17% to 30%. Blinded out-of-sample validations for methylphenidate (n = 41) and multimodal neurofeedback (n = 71) corroborated these findings, yielding a predicted gain in stratified normalized remission of 36% and 29%, respectively.

CONCLUSIONS

This study introduces a clinically interpretable and actionable biomarker based on the iAPF assessed during resting-state electroencephalography. Our findings suggest that acknowledging neurobiological heterogeneity can inform stratification of patients to their individual best treatment and enhance remission rates.

A systematic review of the use of atomoxetine for management of comorbid anxiety disorders in children and adolescents with attention-deficit hyperactivity disorder

BACKGROUND

Anxiety disorders are among the most common comorbid mental disorders in children and adolescents with attention-deficit hyperactivity disorder (ADHD). While the role of atomoxetine, a non-stimulant medication, is well-established in the management of ADHD symptoms since two decades, there is a dearth of evidence regarding its efficacy in the management of anxiety disorders in children and adolescents with ADHD.

AIMS

We aimed to provide insights into (1) the comparative efficacy of atomoxetine in children and adolescents with comorbid ADHD and anxiety disorders, (2) change in severity of anxiety symptoms based on patients', parents', and clinicians' ratings, (3) tolerability and side effects.

METHODS

We searched PubMed, EMBASE, and PsycINFO for clinical trials that addressed the efficacy of atomoxetine for anxiety symptoms in children and adolescents with ADHD. All published literature was systematically reviewed.

RESULTS

We included four studies, out of which two specifically addressed comorbid ADHD and anxiety disorder. The studies suggested that atomoxetine did not exacerbate and in fact reduced anxiety symptoms in young patients with comorbid ADHD.

CONCLUSIONS AND IMPLICATIONS

Overall, atomoxetine demonstrates good efficacy in improving anxiety symptoms in children and adolescents with ADHD. Further studies are needed to shed light on atomoxetine's efficacy for anxiety subtypes in ADHD.

Can Neurocognitive Outcomes Assist Measurement-Based Care for Children with Attention-Deficit/Hyperactivity Disorder? A Systematic Review and Meta-Analyses of the Relationships Among the Changes in Neurocognitive Functions and Clinical Outcomes of Attention-Deficit/Hyperactivity Disorder in Pharmacological and Cognitive Training Interventions

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental conditions among school-age children. Early intervention and ongoing evaluation of treatment effectiveness are essential to minimize the life-long negative impact of ADHD. Neurocognitive functions have been reported to improve with pharmacological and cognitive training interventions for children with ADHD. We evaluated the value of measuring change in neurocognitive functions following ADHD interventions as a treatment outcome. We systematically reviewed randomized control trials of two distinctive types of ADHD interventions-pharmacological treatments and cognitive training-and summarized the changes in neurocognitive and clinical outcomes using a series of meta-analyses. Both pharmacological and cognitive training interventions showed positive effects on some aspects of neurocognitive functions. However, there were no significant correlations between changes in neurocognitive function (e.g., inhibition) and changes in ADHD behavioral symptoms (e.g., impulsive behavior). Although the associations between changes in neurocognitive function and clinical outcomes are not well studied, based on current findings, it is not suitable to use change in neurocognitive outcomes as a proxy for change in ADHD clinical symptom-based outcomes. There is, however, notable value in monitoring changes in neurocognitive function associated with ADHD interventions to achieve the following aims: (1) understanding full treatment effect on children with ADHD, (2) identifying ancillary indicators of subclinical changes, and (3) provision of objective and less biased measures of treatment effects. These findings are important evidence that changes in neurocognitive function could be a co-occurring objective indication that parallels the clinical effects of ADHD treatments.

Atomoxetine and circadian gene expression in human dermal fibroblasts from study participants with a diagnosis of attention-deficit hyperactivity disorder

Atomoxetine (ATO) is a second line medication for attention-deficit hyperactivity disorder (ADHD). We proposed that part of the therapeutic profile of ATO may be through circadian rhythm modulation. Thus, the aim of this study was to investigate the circadian gene expression in primary human-derived dermal fibroblast cultures (HDF) after ATO exposure. We analyzed circadian preference, behavioral circadian and sleep parameters as well as the circadian gene expression in a cohort of healthy controls and participants with a diagnosis of ADHD. Circadian preference was evaluated with German Morningness-Eveningness-Questionnaire (D-MEQ) and rhythms of sleep/wake behavior were assessed via actigraphy. After ex vivo exposure to different ATO concentrations in HDF cultures, the rhythmicity of circadian gene expression was analyzed via qRT-PCR. No statistical significant effect of both groups (healthy controls, ADHD group) for mid-sleep on weekend days, mid-sleep on weekdays, social jetlag, sleep WASO and total number of wake bouts was observed. D-MEQ scores indicated that healthy controls had no evening preference, whereas subjects with ADHD displayed both definitive and moderate evening preferences. ATO induced the rhythmicity of Clock in the ADHD group. This effect, however, was not observed in HDF cultures of healthy controls. Bmal1 and Per2 expression showed a significant ZT × group interaction via mixed ANOVA. Strong positive correlations for chronotype and circadian genes were observed for Bmal1, Cry1 and Per3 among the study participants. Statistical significant different Clock, Bmal1 and Per3 expressions were observed in HDFs exposed to ATO collected from ADHD participants exhibiting neutral and moderate evening preference, as well as healthy participants with morning preferences. The results of the present study illustrate that ATO impacts on circadian function, particularly on Clock, Bmal1 and Per2 gene expression.

Efficacy and Safety of Medication for Attention-Deficit Hyperactivity Disorder in Children and Adolescents with Common Comorbidities: A Systematic Review

Introduction

Comorbid psychiatric conditions in children and adolescents with attention-deficit hyperactivity disorder (ADHD) occur frequently, complicate management, and are associated with substantial burden on patients and caregivers. Very few systematic reviews have assessed the efficacy and safety of medications for ADHD in children and adolescents with comorbidities. Of those that were conducted, most focused on a particular comorbidity or medication. In this systematic literature review, we summarize the efficacy and safety of treatments for children and adolescents with ADHD and comorbid autism spectrum disorders, oppositional defiant disorder, Tourette’s disorder and other tic disorders, generalized anxiety disorder, and major depressive disorder.

Methods

We searched MEDLINE, Embase, and ClinicalTrials.gov (to October 2019) for studies of patients (aged < 18 years) with an ADHD diagnosis and the specified comorbidities treated with amphetamines, methylphenidate and derivatives, atomoxetine (ATX), and guanfacine extended-release (GXR). For efficacy, placebo-controlled randomized controlled trials (RCTs) or meta-analyses of RCTs were eligible for inclusion; for safety, all study types were eligible. The primary efficacy outcome measure was ADHD Rating Scale IV (ADHD-RS-IV) total score.

Results

Of 2177 publications/trials retrieved, 69 were included in this systematic literature review (5 meta-analyses, 37 placebo-controlled RCTs, 16 cohort studies, 11 case reports). A systematic narrative synthesis is provided because insufficient data were retrieved to combine ADHD-RS-IV total scores or effect sizes. Effect sizes for ADHD-RS-IV total scores were available for ten RCTs and ranged from 0.46 to 1.0 for ATX and from 0.92 to 2.0 for GXR across comorbidities. The numbers and types of adverse events in children with comorbidities were consistent with those in children without comorbidities, but treatment should be individualized to ensure children can tolerate the lowest effective dose.

Conclusion

Limited information is available from placebo-controlled RCTs on the efficacy (by ADHD-RS-IV) or safety of medication in children with ADHD and psychiatric comorbidities. Further studies are required to support evidence-based drug selection for these populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00249-0.

The Mechanism, Clinical Efficacy, Safety, and Dosage Regimen of Atomoxetine for ADHD Therapy in Children: A Narrative Review

Atomoxetine, a selective norepinephrine (NE) reuptake inhibitor, was approved for attention deficit/hyperactivity disorder (ADHD) treatment in children, adolescents and adults. We searched the database PubMed/MEDLINE (2000 to October 1, 2021). Only publications in English were considered. Atomoxetine inhibits the presynaptic norepinephrine transporter (NET), preventing the reuptake of NE throughout the brain along with inhibiting the reuptake of dopamine in specific brain regions such as the prefrontal cortex (PFC). The novel mechanism of atomoxetine also includes several new brain imaging studies and animal model studies. It is mainly metabolized by the highly polymorphic drug metabolizing enzyme cytochrome P450 2D6 (CYP2D6). Atomoxetine is effective and generally well tolerated. ADHD is often accompanied by multiple comorbidities. A series of studies have been published suggesting that atomoxetine is effective in the treatment of ADHD symptoms for children with various types of comorbidity. In some cases, it is possible that atomoxetine may have a positive influence on the symptoms of comorbidities. Atomoxetine can be administered either as a single daily dose or split into two evenly divided doses, and has a negligible risk of abuse or misuse. The latest guideline updated that clinical dose selection of atomoxetine was recommended based on both CYP2D6 genotype and the peak concentration. To have a more comprehensive understanding of atomoxetine, this review sets the focus on the mechanism, clinical efficacy and dosage regimen in detail, and also touches on those studies regarding adverse reactions of atomoxetine.

Catecholamines in Alzheimer's Disease: A Systematic Review and Meta-Analysis

Background and Purpose: Previous studies found inconsistent results regarding the relationship between Alzheimer's disease (AD) and catecholamines, such as dopamine (DA), norepinephrine (NE), and epinephrine (EPI). Therefore, the purpose of this study was to perform a systematic review and meta-analysis to evaluate the results of previous studies on this relationship.

Method: Literature retrieval of eligible studies was performed in four databases (Web of Science, PubMed, Embase, and PsycARTICLES). Standardized mean differences (SMDs) were calculated to assess differences in catecholamine concentrations between the AD groups and controls.

Results: Thirteen studies met the eligibility criteria. Compared with the controls, significant lower concentrations of NE (SMD = −1.10, 95% CI: −2.01 to −0.18, p = 0.019) and DA (SMD = −1.12, 95% CI: −1.88 to −0.37, p = 0.003) were observed in patients with AD. No difference was found in the concentrations of EPI between the two groups (SMD = −0.74, 95% CI: −1.85 to 0.37, p = 0.189).

Conclusion: Overall, these findings are in line with the hypothesis that reduced NE and DA may be an important indicator for AD (Registration number CRD42018112816).

Skin Picking Successfully Treated With Atomoxetine in Comorbid Skin Picking and Attention-Deficit/Hyperactivity Disorder: A Case Report

"Skin picking disorder" (SPD: also known as neurotic excoriation, psychogenic excoriation, or dermatillomania) is classified in the "obsessive-compulsive and related disorders" category in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and characterized by unintentional, repetitive skin picking behaviors. Atomoxetine is a selective noradrenaline reuptake inhibitor used in the treatment of attention-deficit/hyperactivity disorder (ADHD). In this case report, we present a 9-year-old girl with the comorbid diagnosis of ADHD and SPD treated successfully with atomoxetine. To our knowledge, this is the first report of skin picking treated with atomoxetine in a patient with ADHD. We discussed possible explanations of mechanisms. Further studies are required on the effectiveness of atomoxetine for the treatment of SPD in the presence and absence of comorbid ADHD.

Atomoxetine Does Not Improve Complex Attention in Idiopathic Parkinson's Disease Patients with Cognitive Deficits: A Meta-Analysis

Objectives

To evaluate the effects of atomoxetine on complex attention and other neurocognitive domains in idiopathic Parkinson's disease (PD).

Methods

Interventional trials reporting changes in complex attention and other neurocognitive functions (Diagnostic and Statistical Manual of Mental Disorders-5) following administration of atomoxetine for at least 8 weeks in adults with idiopathic PD were included. Effect sizes (Cohen's d), the standardized mean difference in the scores of each cognitive domain, were compared using a random-effects model (MetaXL version 5.3).

Results

Three studies were included in the final analysis. For a change in complex attention in PD with mild cognitive impairment (MCI), the estimated effect size was small and nonsignificant (0.16 (95% CI: −0.09, 0.42), n = 42). For changes in executive function, perceptual-motor function, language, social cognition, and learning and memory, the estimated effect sizes were small and medium, but nonsignificant. A deteriorative trend in executive function was observed after atomoxetine treatment in PD with MCI. For a change in global cognitive function in PD without MCI, the estimated effect size was large and significant.

Conclusion

In idiopathic PD with MCI, atomoxetine does not improve complex attention. Also, a deteriorative trend in the executive function was noted.

Methylphenidate Dose-Dependently Affects Aggression and Improves Fear Extinction and Anxiety in BALB/cJ Mice

Overt aggression, increased anxiety, and dysfunctional fear processing are often observed in individuals with conduct disorder (CD) and attention-deficit hyperactivity disorder (ADHD). Methylphenidate (MPH), a psychostimulant increasing dopamine and noradrenaline tone, is effective in reducing aggression in both CD and ADHD individuals. However, it is unclear to which extent these effects of MPH are dose dependent. Here, the effects of acute intraperitoneal MPH (3 and 10 mg/kg) on aggression, anxiety, social behavior, and fear extinction were investigated in BALB/cJ mice. Previous studies in BALB/cJ mice have revealed high levels of aggression and anxiety that are associated with reduced top-down cortical control. Administration of 3 mg/kg MPH prolonged the attack latency and prevented escalation of aggression over time compared to vehicle-treated mice, while 10 mg/kg MPH increased number of bites and attacks. In addition, 3 mg/kg MPH decreased social interaction slightly. A strong anxiolytic effect was found after administration of both the 3 and 10 mg/kg doses in the elevated plus maze and the open-field test. In addition, while vehicle-treated BALB/cJ animals showed intact freezing, both doses of MPH decreased freezing to the unconditioned stimulus in a fear-conditioning paradigm. A long-lasting effect on fear extinction was visible after treatment with the 10 mg/kg dose. The data support a role for MPH in the regulation of anxiety, fear processing, and aggression in BALB/cJ mice, with the latter effect in a dose-dependent manner. The findings provide a further context for examining the effects of MPH in clinical disorders such as ADHD and CD.

Comparative efficacy and tolerability of medications for attention-deficit hyperactivity disorder in children, adolescents, and adults: a systematic review and network meta-analysis

BACKGROUND

The benefits and safety of medications for attention-deficit hyperactivity disorder (ADHD) remain controversial, and guidelines are inconsistent on which medications are preferred across different age groups. We aimed to estimate the comparative efficacy and tolerability of oral medications for ADHD in children, adolescents, and adults.

METHODS

We did a literature search for published and unpublished double-blind randomised controlled trials comparing amphetamines (including lisdexamfetamine), atomoxetine, bupropion, clonidine, guanfacine, methylphenidate, and modafinil with each other or placebo. We systematically contacted study authors and drug manufacturers for additional information. Primary outcomes were efficacy (change in severity of ADHD core symptoms based on teachers' and clinicians' ratings) and tolerability (proportion of patients who dropped out of studies because of side-effects) at timepoints closest to 12 weeks, 26 weeks, and 52 weeks. We estimated summary odds ratios (ORs) and standardised mean differences (SMDs) using pairwise and network meta-analysis with random effects. We assessed the risk of bias of individual studies with the Cochrane risk of bias tool and confidence of estimates with the Grading of Recommendations Assessment, Development, and Evaluation approach for network meta-analyses. This study is registered with PROSPERO, number CRD42014008976.

FINDINGS

133 double-blind randomised controlled trials (81 in children and adolescents, 51 in adults, and one in both) were included. The analysis of efficacy closest to 12 weeks was based on 10 068 children and adolescents and 8131 adults; the analysis of tolerability was based on 11 018 children and adolescents and 5362 adults. The confidence of estimates varied from high or moderate (for some comparisons) to low or very low (for most indirect comparisons). For ADHD core symptoms rated by clinicians in children and adolescents closest to 12 weeks, all included drugs were superior to placebo (eg, SMD -1·02, 95% CI -1·19 to -0·85 for amphetamines, -0·78, -0·93 to -0·62 for methylphenidate, -0·56, -0·66 to -0·45 for atomoxetine). By contrast, for available comparisons based on teachers' ratings, only methylphenidate (SMD -0·82, 95% CI -1·16 to -0·48) and modafinil (-0·76, -1·15 to -0·37) were more efficacious than placebo. In adults (clinicians' ratings), amphetamines (SMD -0·79, 95% CI -0·99 to -0·58), methylphenidate (-0·49, -0·64 to -0·35), bupropion (-0·46, -0·85 to -0·07), and atomoxetine (-0·45, -0·58 to -0·32), but not modafinil (0·16, -0·28 to 0·59), were better than placebo. With respect to tolerability, amphetamines were inferior to placebo in both children and adolescents (odds ratio [OR] 2·30, 95% CI 1·36-3·89) and adults (3·26, 1·54-6·92); guanfacine was inferior to placebo in children and adolescents only (2·64, 1·20-5·81); and atomoxetine (2·33, 1·28-4·25), methylphenidate (2·39, 1·40-4·08), and modafinil (4·01, 1·42-11·33) were less well tolerated than placebo in adults only. In head-to-head comparisons, only differences in efficacy (clinicians' ratings) were found, favouring amphetamines over modafinil, atomoxetine, and methylphenidate in both children and adolescents (SMDs -0·46 to -0·24) and adults (-0·94 to -0·29). We did not find sufficient data for the 26-week and 52-week timepoints.

INTERPRETATION

Our findings represent the most comprehensive available evidence base to inform patients, families, clinicians, guideline developers, and policymakers on the choice of ADHD medications across age groups. Taking into account both efficacy and safety, evidence from this meta-analysis supports methylphenidate in children and adolescents, and amphetamines in adults, as preferred first-choice medications for the short-term treatment of ADHD. New research should be funded urgently to assess long-term effects of these drugs.

FUNDING

Stichting Eunethydis (European Network for Hyperkinetic Disorders), and the UK National Institute for Health Research Oxford Health Biomedical Research Centre.