Differential Treatment Effects of Methylphenidate and Atomoxetine on Executive Functions in Children with Attention-Deficit/Hyperactivity Disorder

Efficacy and Safety of Methylphenidate and Atomoxetine in Medication-Naive Children with Attention-Deficit Hyperactivity Disorder in a Real-World Setting

BACKGROUND AND OBJECTIVE

Methylphenidate (MPH) and atomoxetine (ATX) are the most common medications used to treat attention-deficit hyperactivity disorder (ADHD) in China; however, despite this, there is still a paucity of studies comparing their efficacy and safety, particularly for different characteristics. To address the lack of research, a real-world prospective cohort study was conducted to examine these properties of MPH and ATX, and to analyze correlations associated with age, sex, and different ADHD presentation.

METHODS

Children with ADHD meeting the eligibility criteria were recruited from January 2016 to July 2021. Study participants were treated with either MPH or ATX prescribed in the real-world setting, and were followed up for 26 weeks. Clinical efficacy response and adverse events (AEs) were recorded and measured. Subgroup analysis was performed to examine the efficacy response and AEs associated with age, sex, and different ADHD presentation.

RESULTS

A total of 1050 children were recruited and 29 children were lost to follow-up. Of the 1021 children remaining, 533 were treated with MPH and 488 were treated with ATX. No significant differences were found in intelligence quotient, age, sex, or ADHD presentation between the MPH- and ATX-treated groups (p > 0.05). The response rates were 84.6% in the MPH-treated group and 63.3% in the ATX-treated group. Subgroup analysis of response rate demonstrated that the treatment effect of MPH over ATX was consistent across subgroups except in the girls (odds ratio [OR] 2.09, 95% confidence interval [CI] 0.97-4.7) and the hyperactive/impulsive presentation group (OR 2.88, 95% CI 0.77-12.76). A total of 47.8% of children experienced AEs during MPH treatment, significantly lower than the rate of 56.8% during ATX treatment (p < 0.05). The incidence of AEs in the MPH-treated group was higher in young children (<8 years: 56.8%; 8-10 years: 47.2%) and lower in children over 10 years of age (29.0%).

CONCLUSIONS

Overall, MPH was more effective and better tolerated than ATX. The incidence of AEs in children treated with MPH varied with age, and was higher in young children and lower in children over 10 years of age.

Comparative efficacy of physical activity types on executive functions in children and adolescents: A network meta-analysis of randomized controlled trials

OBJECTIVES

This study investigates the impact of various physical activity (PA) types on executive functions (EFs) in children and adolescents.

DESIGN

A systematic review and network meta-analysis of randomized clinical trials.

METHODS

We searched databases such as PubMed, Embase, Cochrane, and Web of Science up to April 2023, including randomized controlled trials involving 6 distinct PA types for healthy children and adolescents. The Cochrane risk of bias tool was used to assess the risk of bias, and a random-effects model in STATA 17.0 was used to calculate standardized mean differences (SMDs) and 95 % confidence intervals (CI).

RESULTS

Ball Games emerged as the most effective modality for improving updating accuracy, securing a SUCRA score of 94.4 %, and for reducing inhibition reaction time, with a SUCRA score of 94.8 %. Cognitively Engaging Physical Activity led in improving inhibition accuracy with a SUCRA score of 71.7 %. Dance excelled in improving update accuracy and reducing shifting reaction time, with SUCRA scores of 86.6 % and 99.5 %, respectively.

CONCLUSIONS

PA has a significant benefit in EFs in children and adolescents, however the size of the effect varies by type of PA. Ball Games emerged as the most efficacious modality for enhancing updating accuracy and for expediting inhibition reaction time. Cognitively Engaging Physical Activity proved to be the preeminent strategy for improving inhibition accuracy. Dance was distinguished as the optimal approach for improving updating accuracy and reducing shifting reaction time.

Is the deficit in attention-deficit/hyperactivity disorder a concentration deficit?

Attention-deficit/hyperactivity disorder (ADHD) is comprised of two behavioral clusters of symptoms, inattention and hyperactivity/impulsivity. Numerous studies have attempted to address the underlying neuropsychological mechanism of ADHD. However, there is still no uniform mechanism that can fully explain both inattention and hyperactivity/impulsivity symptoms. This review describes the research findings that have shifted the focus from cognitive selective attention to executive function deficits and notes that the prominence of the attention deficit remains unclear. As ADHD is not consistently explained by cognitive selective attention but rather with cognitive sustained attention/vigilance and executive function deficits, this review suggests that concentration deficit is likely the cause of inattention symptoms. Indeed, considering concentration deficit as the cause of inattention symptoms may better describe the underlying difficulties of maintaining and controlling attention in ADHD. In addition, as concentration, impulsivity, and hyperactivity may share a common cognitive deficit, this shift in focus may help in identifying a single mechanism for all ADHD symptoms.

G protein-coupled receptors in neurodegenerative diseases and psychiatric disorders

Neuropsychiatric disorders are multifactorial disorders with diverse aetiological factors. Identifying treatment targets is challenging because the diseases are resulting from heterogeneous biological, genetic, and environmental factors. Nevertheless, the increasing understanding of G protein-coupled receptor (GPCR) opens a new possibility in drug discovery. Harnessing our knowledge of molecular mechanisms and structural information of GPCRs will be advantageous for developing effective drugs. This review provides an overview of the role of GPCRs in various neurodegenerative and psychiatric diseases. Besides, we highlight the emerging opportunities of novel GPCR targets and address recent progress in GPCR drug development.

A Counting Stroop Functional Magnetic Resonance Imaging Study on the Effects of ORADUR-Methylphenidate in Drug-Naive Children with Attention-Deficit/Hyperactivity Disorder

Objective: Methylphenidate is effective in reducing the clinical symptoms of patients with attention-deficit/hyperactivity disorder (ADHD). ORADUR^®-methylphenidate is a new extended-release preparation of methylphenidate. This study aimed at identifying brain regions with activation changes and their correlations with neuropsychological functions after treatment with ORADUR-methylphenidate in children with ADHD. Methods: We recruited drug-naive children with ADHD and age- and sex-matched typically developing (TD) children. They were all scanned with the functional magnetic resonance imaging (fMRI) during the counting Stroop task at baseline, and those with ADHD had the second fMRI assessment after 8-week treatment with ORADUR-methylphenidate. The Rapid Visual Information Processing (RVP) and Conners' Continuous Performance Test (CCPT) were used to assess the attention performance of the ADHD (before and after treatment) and TD groups. Results: ORADUR-methylphenidate significantly decreased inattention (Cohen d = 2.17) and hyperactivity-impulsivity (Cohen d = 0.98) symptoms. We found less activation in the right inferior frontal gyrus (rIFG) in the pre-treatment ADHD children than TD children and greater treatment-induced activation in the dorsal anterior cingulate cortex (dACC) and the right dorsolateral prefrontal cortex (rDLPFC). There was no significant difference between the post-treatment ADHD and TD groups. However, the treatment-related activations in the dACC, rDLPFC, and rIFG were significantly correlated with CCPT and RVP measures. Conclusions: Our findings indicated that ORADUR-methylphenidate increased brain activations in the dACC, rDLPFC, and rIFG in children with ADHD, associated with improved focused attention, reduced impulsivity, and enhanced inhibition control. Activities of these brain regions might be biomarkers for the treatment effectiveness of methylphenidate for ADHD. Clinical Trials Registration: ClinicalTrials.gov number, NCT02450890.

Effectivity of Saffron Extract (Saffr’Activ) on Treatment for Children and Adolescents with Attention Deficit/Hyperactivity Disorder (ADHD): A Clinical Effectivity Study

Attention Deficit/Hyperactivity Disorder is the most prevalent neurodevelopmental disorder worldwide. Choice treatment includes psychostimulants, but parents tend to be reluctant to administer them due to side effects, and alternatives are needed. Saffron extract is a natural stimulant that has been proven safe and effective for treating a variety of mental disorders. This study compares the efficacy of saffron and the usual treatment with methylphenidate, using objective and pen-and-paper tests. We performed a non-randomized clinical trial with two groups, methylphenidate (n = 27) and saffron (n = 36), in children and adolescents aged 7 to 17. Results show that the efficacy of saffron is comparable to that of methylphenidate. Saffron is more effective for treating hyperactivity symptoms, while methylphenidate is more effective for inattention symptoms.

Functional outcomes of extended-release methylphenidate and atomoxetine in children: retrospective chart analysis

Background

Recent guidelines emphasize the importance of functional outcomes in children with attention-deficit/hyperactivity disorder (ADHD). Here, we assess the functional outcomes of the oral delivery system of osmotic-release methylphenidate (OROS-MPH) and atomoxetine (ATX) from the retrospective review of the chart for the last 2 years in the clinic.

Results

Linear mixed-effects models were performed with outcome measures of difference in ADHD symptoms and functional impairment. After 9–12 weeks, OROS-MPH and ATX were statistically equivalent for total Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P) scores (difference in slope is β = 0.004, p = 1.000). However, OROS-MPH was superior to ATX in terms of school domain (difference in slope is β = 0.139, p < 0.001); ATX was superior in the family domain (slope difference in slope is β = 0.103, p < 0.001). The other domains of functioning both were not responsive to pharmacotherapy and were similar between the two medications.

Conclusions

Optimal management should monitor functional progress in ADHD beyond the core symptoms. As expected, ADHD medications provide a distinct pattern of functional improvement. Pharmacotherapy alone offers promising and reliable outcomes to improve school and family functions in ADHD. Some functional improvements did not respond to the medication; therefore, many of the techniques derived from behavioral interventions should be considered.

Executive Functioning in Pediatric Anxiety and Its Relationship to Selective Serotonin Reuptake Inhibitor Treatment Response: A Double-Blind, Placebo-Controlled Trial

Objective: To characterize executive function in adolescents with generalized anxiety disorder (GAD) and its relationship to treatment. Methods: Using data from a double-blind, placebo-controlled trial of escitalopram in adolescents (N = 51) 12-17 years of age with GAD, we used the self-report version of the Behavior Rating Inventory of Executive Function (BRIEF-SR) to assess executive function, at baseline, and examined its relationship to treatment response as measured by the Pediatric Anxiety Rating Scale (PARS). Results: For all baseline subscores of the BRIEF-SR, T-scores were significantly elevated in adolescents with GAD compared to an age- and sex-matched normative healthy sample. In escitalopram-treated patients, baseline BRIEF-SR scores for Emotional Control (β = 0.256, 95% credibility interval [CrI]: 0.367 to 0.146, p < 0.001), Working Memory (β = 0.204, CrI: 0.2952 to 0.1134, p < 0.001), Planning/Organizing (β = -0.223, CrI: -0.1021 to -0.3436, p = 0.004), and Task Completion (β = -0.152, CrI: 0.075 to 0.228, p = 0.002) predicted the trajectory of improvement in PARS score over the 8-week trial. For youth who received placebo, only the Inhibit score was significantly, but weakly, associated with response trajectory (β = -0.081, CrI: -0.0167 to -0.1461, p = 0.015). For adolescents who had clinically significant impairment in Emotional Control, Working Memory, Planning/Organizing, and Task Completion (i.e., T-score >65), the trajectory of improvement significantly differed from patients without scores in the clinically significant range. Conclusions: Taken together, these findings point to the potential value of assessing executive function in youth with anxiety disorders as one strategy for guiding treatment selection. These data suggest that executive function may predict treatment response to psychopharmacologic treatment and point to numerous avenues for further personalizing treatment.

Moderators and Other Predictors of Methylphenidate Response in Children and Adolescents with ADHD

Methylphenidate (MPH) is the treatment of first choice for developmental ADHD. To date, no reliable method to predict how patients will respond to MPH exists and conflicting results are reported on clinical characteristics of responders. The present study aims to give a more precise characterization of the patients who will respond best to MPH to help clinicians in defining the treatment plan. Age, neuropsychological functioning (i.e., attention and working memory), and behavioral/emotional symptoms of 48 drug-naïve children and adolescents with ADHD (42 boys and 6 girls, age-range 6–16 years, mean age 10.5 ± 2.5 years, mean IQ 101.3 ± 11.2) were studied to assess how these different characteristics affected a single-dose MPH response. Four hierarchical linear regression models were used to explore whether age, neuropsychological measures at baseline, and behavioral/emotional symptoms could predict attention and working memory measures after a single-dose MPH administration. We found that improvement in attention and working memory was predicted by age, neuropsychological measures at baseline, and severity of ADHD symptoms. No behavioral and emotional symptoms predicted single-dose MPH response with the exception of conduct symptoms.

The Effects of Drug Treatments for ADHD in Measures of Cognitive Performance

Based on core symptoms of inattention and deficient impulse control, and the identification of effective pharmacotherapies such as amphetamine (AMP; Adderall^®), methylphenidate (MPH; Ritalin^®), and atomoxetine (ATX; Strattera^®), ADHD is a clinical condition which provides opportunity for translational research. Neuropsychological tests such as the 5-Choice and Continuous Performance Tasks, which measure aspects of attention and impulse control in animals and humans, provide scope for both forward (animal to human) and reverse (human to animal) translation. Rodent studies support pro-attentive effects of AMP and MPH and effectiveness in controlling some forms of impulsive behavior. In contrast, any pro-attentive effects of ATX appear to be less consistent, the most reliable effects of ATX are recorded in tests of impulsivity. These differences may account for AMP and MPH being recognized as first-line treatments for ADHD with a higher efficacy relative to ATX. DSM-5 classifies three "presentations" of ADHD: predominantly inattentive type (ADHD-I), predominantly hyperactive/impulsive type (ADHD-HI), or combined (ADHD-C). Presently, it is unclear whether AMP, MPH, or ATX has differential levels of efficacy across these presentation types. Nonetheless, these studies encourage confidence for the forward translation of NCEs in efforts to identify newer pharmacotherapies for ADHD.

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.