Factors affecting treatment adherence to atomoxetine in ADHD: a systematic review

Current nonstimulant medications for adults with attention-deficit/hyperactivity disorder

INTRODUCTION

Stimulants, including methylphenidate and amphetamines, are the first-line pharmacological treatment of ADHD in adults. However, in patients who do not respond or poorly tolerate stimulants, non-stimulant medications are usually recommended.

AREAS COVERED

The authors provide a narrative review of the literature on non-stimulant treatments for adult ADHD, including controlled and observational clinical studies conducted on adult samples. Atomoxetine has been extensively studied and showed significant efficacy in treating adult ADHD. Issues related to dosing, treatment duration, safety, and use in the case of psychiatric comorbidity are summarized. Among other compounds indicated for ADHD in adults, antidepressants sharing at least a noradrenergic or dopaminergic component, including tricyclic compounds, bupropion, and viloxazine, have shown demonstratable efficacy. Evidence is also available for antihypertensives, particularly guanfacine, as well as memantine, metadoxine, and mood stabilizers, while negative findings have emerged for galantamine, antipsychotics, and cannabinoids.

EXPERT OPINION

While according to clinical guidelines, atomoxetine may serve as the only second-line option in adults with ADHD, several other nonstimulant compounds may be effectively used in order to personalize treatment based on comorbid conditions and ADHD features. Nevertheless, further research is needed to identify and test more personalized treatment strategies for adults with ADHD.

Short- and Long-Term Outcomes of Suboptimal Medication Adherence in Adolescents with Attention-Deficit/Hyperactivity Disorder: A Systematic Literature Review

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition with severe and life-long consequences. Adolescents and young adults represent a particularly vulnerable subgroup because of the unique demands of their developmental stage. Despite the well-known efficacy of medication treatment for ADHD, there remains a notable concern regarding poor medication adherence in this population. Objectives: This systematic literature review aimed to synthesize the existing empirical evidence on the outcomes and consequences of medication nonadherence among adolescents and young adults with ADHD. Methods: An extensive database search was conducted on September 26, 2022, with no time limits applied. The databases included Scopus, PubMed, CINAHL, Cochrane, and PsycINFO. Results: Six studies met the inclusion criteria. Each study revealed that medication nonadherence was associated with a range of adverse outcomes, including decreased academic performance, heightened familial, and psychological stress, and an increased likelihood of substance use, pregnancy, obesity, and injury. Conversely, adherence led to improvements in at least one ADHD-related outcome. Conclusions: Research exploring the consequences of suboptimal medication adherence in adolescents and young adults with ADHD is currently limited, and effective strategies to address this issue remain scarce. A thorough understanding of such consequences is critical for developing interventions aimed at improving medication adherence and mitigating the risk of adverse outcomes, especially considering the susceptibility of this population.

Longitudinal Patterns of Community-Based Treatment Utilization Among Ethnically and Racially Diverse Adolescents with Attention-Deficit/Hyperactivity Disorder

Background: Attention-deficit/hyperactivity disorder (ADHD) treatment utilization among adolescents is highly variable. This article describes pharmacological and nonpharmacological treatment utilization in a community sample of primarily Latinx and/or Black adolescents with ADHD (N = 218), followed longitudinally for 4 years, from early adolescence until approximately age 17 (M = 16.80, standard deviation = 1.65). Methods: Electronic surveys administered between 2012 and 2019 queried parent and youth reports of medication initiation, persistence, diversion, and misuse, as well as reasons for desistence. Nonpharmacological treatment utilization (including complementary and alternative treatments) was also measured. Results: Results indicated that: (1) the majority of the sample sought treatment for ADHD in their community, (2) rates of psychosocial treatment utilization were higher than medication utilization, (3) approximately half of the medicated sample discontinued community-administered ADHD medication during the follow-up period, most frequently citing tolerability issues and concerns that they were "tired of taking" medication, and (4) medication misuse consisted of youth diversion and parent utilization of teen medication, but both were reported at low rates. Race/ethnicity did not predict treatment utilization patterns, but lower family adversity and psychiatric comorbidity predicted persistence of medication use over time. Conclusions: ADHD treatment engagement efforts for Latinx and/or Black adolescents might link treatment to goals valued by the youth, address concerns related to medication tolerability, and promote secure monitoring of medication. Nonpharmacological treatments for ADHD may be more palatable to Latinx and Black youth with ADHD, and efforts to engage youth with ADHD in treatment should consider offering medication and psychosocial treatment options.

Inclusion of a computerized test in ADHD diagnosis process can improve trust in the specialists' decision and elevate adherence levels

Attention deficit and hyperactivity disorder (ADHD) affects many life aspects of children and adults. Accurate identification, diagnosis and treatment of ADHD can facilitate better care. However, ADHD diagnosis and treatment methods are subject of controversy. Objective measures can elevate trust in specialist's decision and treatment adherence. In this observational study we asked whether knowing that a computerized test was included in ADHD diagnosis process results in more trust and intention to adhere with treatment recommendations. Questionnaires were administered to 459 people, 196 men, average age = 40.57 (8.90). Questions regarding expected trust and adherence, trust trait, trust in physician and health-care-institutions, and ADHD scales followed a scenario about parents referred to a neurologist for sons' ADHD diagnosis. The scenario presented to the test group (n = 185) mentioned that a computerized test was part of the diagnostic process. The control group scenario didn't mention any computerized test in the diagnostic process. Test group participants expressed more trust in the diagnosis and greater levels of intention for treatment adherence. Group differences in intention for treatment adherence were mediated by trust in decision. Inclusion of a computerized test in ADHD diagnosis process can improve trust in the specialists' decision and elevate adherence levels.

Personalizing atomoxetine dosing in children with ADHD: what can we learn from current supporting evidence

PURPOSE

There is marked heterogeneity in treatment response of atomoxetine in patients with attention deficit/hyperactivity disorder (ADHD), especially for the pediatric population. This review aims to evaluate current evidence to characterize the dose-exposure relationship, establish clinically relevant metrics for systemic exposure to atomoxetine, define a therapeutic exposure range, and to provide a dose-adaptation strategy before implementing personalized dosing for atomoxetine in children with ADHD.

METHODS

A comprehensive search was performed across electronic databases (PubMed and Embase) covering the period of January 1, 1985 to July 10, 2022, to summarize recent advances in the pharmacokinetics, pharmacogenomics/pharmacogenetics (PGx), therapeutic drug monitoring (TDM), physiologically based pharmacokinetics (PBPK), and population pharmacokinetics (PPK) of atomoxetine in children with ADHD.

RESULTS

Some factors affecting the pharmacokinetics of atomoxetine were summarized, including food, CYP2D6 and CYP2C19 phenotypes, and drug‒drug interactions (DDIs). The association between treatment response and genetic polymorphisms of genes encoding pharmacological targets, such as norepinephrine transporter (NET/SLC6A2) and dopamine β hydroxylase (DBH), was also discussed. Based on well-developed and validated assays for monitoring plasma concentrations of atomoxetine, the therapeutic reference range in pediatric patients with ADHD proposed by several studies was summarized. However, supporting evidence on the relationship between systemic atomoxetine exposure levels and clinical response was far from sufficient.

CONCLUSION

Personalizing atomoxetine dosage may be even more complex than anticipated thus far, but elucidating the best way to tailor the non-stimulant to a patient's individual need will be achieved by combining two strategies: detailed research in linking the pharmacokinetics and pharmacodynamics in pediatric patients, and better understanding in nature and causes of ADHD, as well as environmental stressors.

Sociodemographic and Clinical Factors Affecting Treatment Adherence in Adults with Attention Deficit and Hyperactivity Disorder

Background

This study aims to explore sociodemographic and clinical factors affecting medication adherence in adults with attention deficit and hyperactivity disorder and elicit dysfunctional domains and comorbidities with a focus on gender differences.

Methods

Patients were recruited from 2 specialty clinics using chart records in a natural treatment design. Adult attention deficit and hyperactivity disorder self-report scale, Diagnostic Interview for attention deficit and hyperactivity disorder in adults, was applied. Adherence is defined if the patient declared ≥80% adherence to medication throughout the last 8-12 weeks.

Results

From 205 attention deficit and hyperactivity disorder patients (male = 112 female = 93 (age (median) min-max = 29 (18-56)), 29% were non-adherent to attention deficit and hyperactivity disorder medication. In the multivariate analysis, having 2 or more comorbid disorders (P = .009), dysfunctions in academic/work (P = .049), and dysfunctions in family and other relationships (P = .047) increased the likelihood of adherence. Adherence rates did not significantly differ between methylphenidate and atomoxetine (P = .405). Women were more likely to have 2 or more comorbid psychiatric disorders (P = .004) and dysfunctions in social relationships (P = .001), free time activities, hobbies (P < .001), self-confidence, and self-image (P < .001).

Results

Nearly one-third of adult patients with attention deficit and hyperactivity disorder did not adhere to medication treatment. Comorbid psychiatric disorders and dysfunctions in life domains appear to increase the likelihood of adherence to attention deficit and hyperactivity disorder medications, possibly through increasing motivation for treatment. The effect of cognitive-behavioral therapy on compliance with attention deficit and hyperactivity disorder medication should further be explored with prospective controlled studies.

Conclusion

We suggest that future longitudinal studies use objective measures of adherence and confirm the role of dysfunctional life domains and comorbid psychiatric disorders as correlates of medication adherence.

Effects of Combing Group Executive Functioning and Online Parent Training on School-Aged Children With ADHD: A Randomized Controlled Trial

OBJECTIVE

The acceptance of drug treatment for younger children with attention-deficit/hyperactivity disorder (ADHD) in China remains low. Here, we explored the clinical benefits of a non-pharmaceutical intervention method combining a group and executive function training and an online parent training program, termed group executive functioning and online parent training (GEF-OPT), for school-aged students with ADHD through a randomized controlled trial.

METHOD

A total of 145 children (aged 6-8 years) were formally registered and randomized to the intervention group (n = 73) and waitlist group (n = 72). The enrolled children received eight sessions of GEF-OPT treatment, which consists of a hospital-based children executive function (EF) training program and an online parent training program. Treatment outcome was assessed by a parent/teacher report questionnaire and neurophysiological experiment.

RESULTS

After eight sessions of intervention, children in the intervention group showed a significant improvement in inattentive symptom compared to the waitlist group (14.70 ± 4.35 vs. 16.03 ± 2.93; p = 0.024), but an insignificant difference in hyperactive-impulsivity (9.85 ± 5.30 vs. 10.69 ± 5.10; p = 0.913). Comorbid oppositional defiant disorder was significantly reduced in the intervention group (7.03 ± 4.39 vs. 8.53 ± 4.41; p = 0.035). Children in the intervention group had greater reduction in the scores of behavioral regulation index (inhibition, emotional control) and metacognition index (working memory, planning/organization, monitoring) in executive function than those in the waitlist group (p < 0.05). Significant effects were also found in learning problem of Weiss Functional Impairment Scale-Parent form and parental distress between two groups at post-treatment (p < 0.05). In line with this, the result of go/no-go task showed significant improvements in accuracy change (4.45 ± 5.50% vs. 1.76 ± 3.35%; p = 0.001) and reaction time change (47.45 ± 62.25 s vs. 16.19 ± 72.22 s; p = 0.007) in the intervention group compared with the waitlist group.

CONCLUSION

We conclude that participants in the GEF-OPT program improved outcomes for inattentive symptom, executive function, learning problems, and parental distress. GEF-OPT is a promising non-pharmaceutical therapeutic option for younger children.

TRIAL REGISTRATION

ChiCTR2100052803.

The lowest effective plasma concentration of atomoxetine in pediatric patients with attention deficit/hyperactivity disorder: A non-randomized prospective interventional study

BACKGROUND

Atomoxetine (ATX) is used as a first-line, non-stimulant treatment for attention-deficit/hyperactivity disorder (ADHD), although no studies have systematically examined the relationship between plasma concentration and clinical efficacy. We conducted this non-randomized prospective interventional study to examine the relationship between plasma concentration of ATX and clinical efficacy.

METHODS

Forty-three ADHD pediatric patients received ATX, and the steady-state through plasma concentration of the last daily dose that was maintained for at least 4 weeks were determined by high-performance liquid chromatography.

RESULTS

The receiver operating characteristic curve suggested that when plasma concentration exceeded 64.60 ng/mL, scores on the ADHD-Rating Scale improved by 50% or more (P = .14). Although 6 of the 8 final responders were unresponsive at the initial dose (.72 ± .04 mg/kg [mean ± standard deviation]), they responded after increasing the ATX dose to the final dose (1.52 ± .31 mg/kg). Excluding 7 outlier participants, the concentration was 83.3 ± 32.3 ng/mL in 7 responders and was significantly higher than 29.5 ± 23.9 ng/mL (P < .01) for the 29 non-responders.

CONCLUSIONS

These results suggest that a minimum effective plasma concentration of ATX is required to achieve sufficient clinical efficacy. We hypothesized a mechanism that results in the realization of a clinical effect when the plasma concentration exceeds a certain threshold in the potential response group, whereas will not improve even if the plasma concentration is increased in the unqualified non-responder group.

Challenges in ADHD care for ethnic minority children: A review of the current literature

While attention deficit hyperactivity disorder (ADHD) has been extensively studied in the past decades, the role of social and cultural practices in its assessment, diagnosis, and treatment has been often overlooked. This selective review provides an overview of research that explores social and cultural influences on help-seeking behavior in ethnic minority children with ADHD. Studies were selected that address cultural diversity in three areas of ADHD help-seeking: problem recognition, access to mental health services, and treatment. Special attention was given to studies of treatment selection and adherence in minority groups. Findings suggested that cultural disparities in ADHD care among ethnic minority children occur in the early stages of problem recognition, through service selection, and in the quality of treatment. Ethnic minority children were less likely than their nonminority counterparts to be diagnosed with ADHD and its comorbid conditions and less likely to be prescribed and adhere to stimulant drug treatment. These differences reflect cultural diversity in norms and attitudes towards mental health issues (e.g., fear of social stigma) as well as limited access to qualified health care. Paradoxically, cultural, racial, and language bias may also lead to the overidentification of ethnic minority children as disabled and to higher ratings of ADHD symptoms. This review highlights the importance of sociocultural factors in understanding developmental psychopathology and help-seeking behavior. In addition, it further supports calls for increasing cultural competence in communications during clinical assessment, diagnosis, and treatment in minority communities. Clinical, theoretical, and methodological considerations for future research are discussed.

Prediction of drop-out and outcome in integrated cognitive behavioral therapy for ADHD and SUD: Results from a randomized clinical trial

BACKGROUND

Patients with substance use disorder (SUD) or Attention Deficit Hyperactivity Disorder (ADHD) have a high risk of drop out from treatment. Few studies have investigated predictors of therapy drop out and outcome in SUD patients with comorbid ADHD. Recently, integrated cognitive behavioral therapy (CBT/Integrated) was shown to be more effective than standard CBT (CBT/SUD) in the treatment of SUD + ADHD.

OBJECTIVE

To investigate the association of demographic, clinical and neurocognitive variables with drop-out and treatment outcome, and to examine which of these variables are suitable for patient-treatment matching.

METHODS

We performed an RCT in which 119 patients were allocated to CBT/Integrated (n = 60) or CBT/SUD (n = 59). In addition, 55 patients had dropped out before randomization. Demographic variables, clinical characteristics and measures of cognitive functioning (Stroop, Tower of London (ToL) and Balloon Analogue Risk Task (BART)) were included as predictors. Outcome measures were: early treatment drop-out, ADHD symptom severity, and substance use severity at end of treatment and follow up.

RESULTS

Primary substance of abuse (drugs as opposed to alcohol only) and lower accuracy scores on the ToL were significant predictors of early treatment drop-out. Having more depression and anxiety symptoms and using ADHD medication at baseline significantly predicted more ADHD symptoms at end of treatment, and higher accuracy scores on the ToL significantly predicted higher substance use at end of treatment. No significant predictor-by-treatment interactions were found.

CONCLUSION

The results add to the existing realization that also relatively mild cognitive deficits are a risk factor for treatment drop-out in these patients.

A Review of Factors Influencing the Three Phases of Medication Adherence in People with Attention-Deficit/Hyperactivity Disorder

Objectives: Factors affecting adherence to medications in people with attention-deficit/hyperactivity disorder (ADHD) are not well understood in the context of their influence on the different phases of adherence, that is, initiation, implementation, and discontinuation. This review aimed to identify the factors affecting the three phases of medication adherence in people with ADHD. Methods: Six electronic databases, including Medline, PubMed, IPA, CINAHL, Embase, and PsycINFO, were systematically searched from inception through October 2018 with the limitations of English language and human studies. The search strategy was based on three concepts (adherence, ADHD, and factors) and their relevant terminologies. Results: Considerable variability was observed with regards to the criteria used to define adherence in identified studies (n = 48). Most studies focused on the implementation phase of adherence (n = 27), while only a handful focused on the initiation (n = 6) and discontinuation (n = 5) phase of adherence. The remaining studies (n = 10) examined multiple phases of adherence. Conflicting information received about medication, medication frequency, and fears of medication's effect on growth were the unique factors impacting initiation, implementation, and discontinuation, respectively. Moreover, factors within each phase of adherence also differed with different populations such as parents, children, adolescents, and adults. Fear of addiction, medication effectiveness, psychiatric comorbidity, and medication side effects were the most common factors identified in all three phases of adherence. Conclusions: This review found some unique factors in each phase of adherence while some overlap was also noted. Future interventions to improve adherence should be phase- and group specific rather than consider adherence as a single variable.