Safety of Methylphenidate and Atomoxetine in Children with Attention-Deficit/Hyperactivity Disorder (ADHD): Data from the Italian National ADHD Registry

Psychosis with use of amphetamine drugs, methylphenidate and atomoxetine in adolescent and adults

BACKGROUND

Use of psychostimulants and relative drugs has increased worldwide in treatment of attention-deficit hyperactivity disorder (ADHD) in adolescents and adults. Recent studies suggest a potential association between use of psychostimulants and psychotic symptoms. The risk may not be the same between different psychostimulants.

OBJECTIVE

To assess whether amphetamine or atomoxetine use is associated with a higher risk of reporting symptoms of psychosis than methylphenidate use in adolescents and adults, particularly in patients with ADHD.

METHODS

Using VigiBase, the WHO's pharmacovigilance database, disproportionality of psychotic symptoms reporting was assessed among adverse drug reactions related to methylphenidate, atomoxetine and amphetamines, from January 2004 to December 2018, in patients aged 13-25 years. The association between psychotic symptoms and psychostimulants was estimated through the calculation of reporting OR (ROR).

FINDINGS

Among 13 863 reports with at least one drug of interest, we found 221 cases of psychosis with methylphenidate use, 115 with atomoxetine use and 169 with a prescription of an amphetamine drug. Compared with methylphenidate use, amphetamine use was associated with an increased risk of reporting psychotic symptoms (ROR 1.61 (95% CI 1.26 to 2.06)]. When we restricted the analysis to ADHD indication, we found a close estimate (ROR 1.94 (95% CI 1.43 to 2.64)). No association was found for atomoxetine.

CONCLUSION

Our study suggests that amphetamine use is associated with a higher reporting of psychotic symptoms, compared with methylphenidate use.

CLINICAL IMPLICATIONS

The prescription of psychostimulants should consider this potential adverse effect when assessing the benefit-risk balance.

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.

Adverse Events During Dosing of Delayed-release/Extended-release Methylphenidate: Learnings From the Open-label Phase of a Registration Trial and a Real-world Postmarketing Surveillance Program

PURPOSE

Delayed-release/extended-release methylphenidate (DR/ER-MPH) (formerly HLD200) is an evening-dosed agent used for the treatment of attention-deficit/hyperactivity disorder. Postmarketing surveillance data from approximately 74,000 patients exposed to DR/ER-MPH (up to June 17, 2022) were reported and compared with the open-label, treatment-optimization phase of a Phase III clinical trial to derive possible learnings on how to approach adverse events (AEs) that emerge during dose titration.

METHODS

An analysis of AEs spontaneously reported to Ironshore in postmarketing surveillance included, where available, age, dose, timing, and discontinuations. Data were summarized using descriptive statistics.

FINDINGS

A total of 395 children, adolescents, and adults reported 601 AEs in postmarketing surveillance. Five AEs were classified as serious. AEs preceded drug use discontinuation in 172 patients. Many AEs occurred early (52% were reported within 30 days) and at lower doses (54% were reported at 20 to 40 mg), similar to the trial data. Reported AEs included those similar in type but orders of magnitude lower in number than those from the clinical trial.

IMPLICATIONS

No new safety concerns were revealed in this real-world setting compared with the safety profile identified in DR/ER-MPH trial data. In real-world practices, clinicians tended to discontinue DR/ER-MPH treatment after AE onset, whereas trial investigators continued to optimize treatment and found that AEs were generally tolerable, suggesting that health care practitioners may consider developing strategies to manage tolerability issues with DR/ER-MPH treatment on AE emergence rather than immediately discontinuing use of the drug to provide optimal therapeutic benefit.

CLINICALTRIALS

gov identifier: NCT02493777.

Revisiting stimulant use for emotional dysregulation in attention-deficit/hyperactivity disorder (ADHD)

INTRODUCTION

Emotional dysregulation (ED) symptoms are present in a considerable portion of patients with attention-deficit/hyperactivity disorder (ADHD). In recent years, an increasing number of studies investigated the effects of stimulant medications on ED in patients with ADHD.

AREAS COVERED

A narrative review of the literature on stimulant treatment for ED is provided, including controlled and observational clinical studies conducted on pediatric and adult samples and neurobiological investigations. Positive effects of stimulants on irritability have been demonstrated in children. Comorbidity with disruptive behavior disorders (DBD) and disruptive mood dysregulation disorder does not prevent stimulant effectiveness. Methylphenidate has also been found to reduce temper problems, affective instability, and emotional over-reactivity in adults with ADHD, although with variable effect sizes. A variety of adverse emotional effects have been reported, especially at high doses and in special populations. However, several possible confounders of treatment-emergent ED have been highlighted. Finally, according to neuroimaging studies, stimulants may mitigate emotional processing anomalies associated with ADHD.

EXPERT OPINION

The findings are consistent with models including ED within the core features of ADHD. Stimulant treatment should be prioritized over antipsychotics in ADHD-DBD. It remains to be elucidated whether other medications may be more effective in specific populations with ADHD and/or ED.

An updated safety review of the current drugs for managing ADHD in children

INTRODUCTION

Attention-Deficit/Hyperactivity Disorder (ADHD) is a highly prevalent condition that causes persistent problems with attention and/or hyperactivity-impulsivity and often results in significant impairment when left untreated. Medications for this disorder continue to evolve and provide new treatment options. Ongoing review of related medication safety and tolerability remains an important task for prescribers.

AREAS COVERED

This manuscript provides an updated safety review of medications used to treat ADHD in children and adolescents. PubMed and OneSearch online databases were utilized to search for literature relevant to the topic of ADHD medications and safety. Clinical trials of medications used to treat ADHD, systematic reviews and meta-analyses, and articles covering specific safety issues (adverse or unfavorable events) such as cardiovascular effects, seizures, impact on growth, depression, suicidal ideation, substance use disorders, psychosis, and tics are described.

EXPERT OPINION

Available pharmacologic treatments for ADHD have favorable efficacy, safety and tolerability and allow many patients to achieve significant improvement of their symptoms. Despite the availability of multiple stimulant and non-stimulant formulations, some individuals with ADHD may not tolerate available medications or attain satisfactory improvement. To satisfy unmet clinical needs, ADHD pharmaceutical research with stimulant and nonstimulant formulations targeting dopamine, norepinephrine, and novel receptors is ongoing.

Epilepsy and attention-deficit/hyperactivity disorder in children and adolescents: An overview of etiology, prevalence, and treatment

Epilepsy and attention-deficit/hyperactivity disorder (ADHD) are closely connected and commonly seen in both children and adults. Each of the disorders has major psychosocial and quality of life (QOL) effects, and their co-occurrence makes coping even more challenging for both the patients and their families. Moreover, an adverse effect of some anti-seizure medications can potentially induce or exacerbate symptoms of ADHD on the one hand, while some ADHD medications may increase seizure risk on the other. The combination of proper diagnosis and appropriate treatment may improve or even prevent many of the complications associated with these conditions. The objectives of this review are to present the complex relationship between epilepsy and ADHD, looking into the pathophysiological, anatomical, and functional perspectives along with the psychosocial and QOL influences and the recommended treatment approaches in accordance with the latest literature.

Long-term safety of methylphenidate in children and adolescents with ADHD: 2-year outcomes of the Attention Deficit Hyperactivity Disorder Drugs Use Chronic Effects (ADDUCE) study

BACKGROUND

Methylphenidate is the most frequently prescribed medication for the treatment of ADHD in children and adolescents in many countries. Although many randomised controlled trials support short-term efficacy, tolerability, and safety, data on long-term safety and tolerability are scarce. The aim of this study was to investigate the safety of methylphenidate over a 2-year period in relation to growth and development, psychiatric health, neurological health, and cardiovascular function in children and adolescents.

METHODS

We conducted a naturalistic, longitudinal, controlled study as part of the ADDUCE research programme in 27 European child and adolescent mental health centres in the UK, Germany, Switzerland, Italy, and Hungary. Participants aged 6-17 years were recruited into three cohorts: medication-naive ADHD patients who intended to start methylphenidate treatment (methylphenidate group), medication-naive ADHD patients who did not intend to start any ADHD medication (no-methylphenidate group), and a control group without ADHD. Children with ADHD diagnosed by a qualified clinician according to the DSM-IV criteria and, in the control group, children who scored less than 1·5 on average on the Swanson, Nolan, and Pelham IV rating scale for ADHD items, and whose hyperactivity score on the parent-rated Strengths and Difficulties Questionnaire was within the normal range (<6) were eligible for inclusion. Participants were excluded if they had previously taken any ADHD medications but remained eligible if they had previously taken or were currently taking other psychotropic drugs. The primary outcome was height velocity (height velocity SD score; estimated from at least two consecutive height measurements, and normalised with reference to the mean and SD of a population of the same age and sex).

FINDINGS

Between Feb 01, 2012, and Jan 31, 2016, 1410 participants were enrolled (756 in methylphenidate group, 391 in no-methylphenidate group, and 263 in control group). 1070 (76·3%) participants were male, 332 (23·7%) were female, and for eight gender was unknown. The average age for the cohort was 9·28 years (SD 2·78; IQR 7-11). 1312 (93·0%) of 1410 participants were White. The methylphenidate and no-methylphenidate groups differed in ADHD symptom severity and other characteristics. After controlling for the effects of these variables using propensity scores, there was little evidence of an effect on growth (24 months height velocity SD score difference -0·07 (95% CI -0·18 to 0·04; p=0·20) or increased risk of psychiatric or neurological adverse events in the methylphenidate group compared with the no-methylphenidate group. Pulse rate and systolic and diastolic blood pressure were higher in the methylphenidate group compared with the no-methylphenidate group after 24 months of treatment. No serious adverse events were reported during the study.

INTERPRETATION

Our results suggest that long-term treatment with methylphenidate for 2 years is safe. There was no evidence to support the hypothesis that methylphenidate treatment leads to reductions in growth. Methylphenidate-related pulse and blood pressure changes, although relatively small, require regular monitoring.

FUNDING

EU Seventh Framework Programme.

Prescription Stimulants in College and Medical Students: A Narrative Review of Misuse, Cognitive Impact, and Adverse Effects

Stimulants are effective in treating attention-deficit/hyperactivity disorder (ADHD). Psychiatrist Charles Bradley first made this discovery in 1937 when he found that children treated with amphetamines showed improvements in school performance and behavior. Between 1995 and 2008, stimulants to treat ADHD increased six-fold among American adults and adolescents at an annual rate of 6.5%. Stimulants without a prescription, known as nonmedical use or misuse, have also increased. The highest rates of nonmedical prescription drug misuse in the United States are seen most notably in young adults between 18 and 25 years, based on data from the Substance Abuse and Mental Health Services Administration in 2021. Aside from undergraduate students, nonmedical prescription stimulant use is prevalent among medical students worldwide. A recent literature review reported the utilization of stimulants without a prescription in 970 out of 11,029 medical students. The percentages of medical students across the country misusing stimulants varied from 5.2% to 47.4%. Academic enhancement, reported in 50% to 89% of college students with stimulant misuse, is the most common reason for nonmedical stimulant use. With the increasing use of stimulants among adolescents and adults, it is unclear what long-term outcomes will be since little data are available that describe differences in how side effects are experienced for prescribed and non-prescribed users. The present narrative review focuses on these adverse effects in this population and the reasonings behind misuse and nonmedical use.

Attention Deficit Hyperactivity Disorder Medications and Sleep

Sleep problems are common and often increase when initiating pharmacotherapy for ADHD. Stimulants are commonly associated with delayed sleep onset/insomnia although nonstimulants can be associated with daytime sleepiness. There is a wide variability in severity and duration of sleep effects, but most effects are mild and improve over time. Although sleep problems occur in all age groups, preschoolers and adolescents appear to be more vulnerable to adverse effects on sleep than adults and children. Interventions to improve sleep include behavioral therapy, changing dose schedules or formulations, and adding a sleep-promoting agent such as melatonin.

Evidence of methylphenidate effect on mitochondria, redox homeostasis, and inflammatory aspects: Insights from animal studies

Methylphenidate (MPH) is a central nervous system (CNS) stimulant known for its effectiveness in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), a neuropsychiatric condition that has a high incidence in childhood and affects behavior and cognition. However, the increase in its use among individuals who do not present all the diagnostic criteria for ADHD has become a serious public health problem since the neurological and psychiatric consequences of this unrestricted use are not widely known. In addition, since childhood is a critical period for the maturation of the CNS, the high prescription of MPH for preschool children also raises several concerns. This review brings new perspectives on how MPH (in different doses, routes of administration and ages) affects the CNS, focusing on animal studies that evaluated changes in mitochondrial (bioenergetics), redox balance and apoptosis, as well as inflammatory parameters. MPH alters brain energy homeostasis, increasing glucose consumption and impairing the activity of enzymes in the Krebs cycle and electron transport chain, as well as ATP levels and Na⁺,K⁺-ATPase activity. MPH induces oxidative stress, increasing the levels of reactive oxygen and nitrogen species and altering enzymatic and non-enzymatic antioxidant defenses, which, consequently, is related to damage to proteins, lipids, and DNA. Among the harmful effects of MPH, studies also demonstrate its ability to induce inflammation as well as alter the apoptosis pathway. It is important to highlight that age, treatment time, administration route, and dose are factors that can influence MPH effects. However, young animals seem to be more susceptible to damage caused by MPH. It is possible that changes in mitochondrial function and markers of status oxidative, apoptosis and inflammation may be exerting important mechanisms associated with MPH toxicity and, therefore, the unrestricted use of this drug can cause brain damage.

Personalization of pharmacological treatments for ADHD: Why it is advisable and possible options to achieve it

Abstract:

Attention-deficit hyperactivity disorder is a neurodevelopmental disorder diagnosed primarily in children, although it is also present in adults. Patients present inattention, impulsivity, and hyperactivity symptoms that create difficulties in their daily lives. Pharmacological treatment with stimulants or non-stimulants is used most commonly to reduce ADHD symptoms. Although generally effective and safe, pharmacological treatments have different effects among patients, including lack of response and adverse reactions. The reasons for these differences are not fully understood, but they may derive from the highly diverse etiology of ADHD. Strategies to guide optimal pharmacological treatment selection on the basis of individual patients’ physiological markers are being developed. In this review, we describe the main pharmacological ADHD treatments used and their main drawbacks. We present alternatives under study that would allow the customization of pharmacological treatments to overcome these drawbacks and achieve more reliable improvement of ADHD symptoms.

Prescription Stimulants and the Risk of Psychosis: A Systematic Review of Observational Studies

PURPOSE/BACKGROUND

Stimulants can cause psychotic symptoms at high doses and with parenteral use, but it remains uncertain whether the clinical use of prescription stimulants (PS) at therapeutic doses precipitates psychosis or influences long-term psychosis risk. Although serious, psychosis is a relatively uncommon event that is difficult to detect in brief randomized controlled trials. There have been several large-scale observational studies of PS and psychosis risk, which have not been reviewed; therefore, we conducted a systematic review of observational studies of PS and psychosis risk in adults and children.

METHODS/PROCEDURE

We conducted a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol was registered with International Prospective Register of Systematic Reviews (CRD42021243484). Eligible studies were longitudinal observational studies, either cohort or case-control, published in English that reported on PS exposure and risk of psychotic events or disorders. Risk of bias assessments were performed with the ROBINS-I instrument.

FINDINGS/RESULTS

There were 10,736 reports screened, and 8 were ultimately included (n = 232,567 patients): 4 retrospective cohort studies, 1 nested case-control study, 2 self-controlled case series, and 1 prospective cohort study. Exposure to methylphenidate (MPH) was more commonly studied than amphetamine (AMPH). In the 3 studies with lowest risk of bias, there was no effect of MPH exposure on psychosis risk, but there was evidence for increased risk with AMPH in 1 study.

IMPLICATIONS/CONCLUSIONS

We conclude that observational studies do not support a clear-cut effect of prescribed MPH on psychosis risk but that AMPH has been less well studied and may increase psychosis risk.

The effects of stimulant dose and dosing strategy on treatment outcomes in attention-deficit/hyperactivity disorder in children and adolescents: a meta-analysis

Clinical guidelines currently recommend practitioners titrate stimulant medications, i.e., methylphenidate (MPH) and amphetamines (AMP), to the dose that maximizes symptom control without eliciting intolerable adverse events (AEs) when treating attention-deficit/hyperactivity disorder (ADHD) in school-aged children/adolescents. However, robust evidence-base regarding the effects of doses and dosing strategies of stimulants on clinical outcomes in the treatment of children/adolescents with ADHD is currently lacking and stimulants are often underdosed in clinical practice. To address this gap and provide rigorous evidence-base in relation to the dose and dosing strategy of stimulants, we conducted the largest systematic review and dose-response meta-analysis examining change in ADHD symptoms (efficacy), and treatment discontinuations due to AEs (tolerability) and any reason (acceptability). We conducted one-stage random-effects dose-response meta-analyses examining MPH and AMP separately, stratifying trials based on fixed-dose and flexible-dose design. Daily doses of stimulants were converted to MPH- and AMP-equivalent doses by adjusting for different pharmacokinetics across formulations. We also conducted pairwise meta-analyses to provide indirect comparisons between flexible-dose versus fixed-dose trials. Our study included 65 RCTs involving 7 877 children/adolescents. Meta-analyses of fixed-dose trials for both MPH and AMP demonstrated increased efficacy and increased likelihood of discontinuation due to AEs with increasing doses of stimulants. The incremental benefits of stimulants in terms of efficacy decreased beyond 30 mg of MPH or 20 mg of AMP in fixed-dosed trials. In contrast, meta-analyses of flexible-dose trials for both MPH and AMP demonstrated increased efficacy and reduced likelihood of discontinuations for any reason with increasing stimulant doses. The incremental benefits of stimulants in terms of efficacy remained constant across the FDA-licensed dose range for MPH and AMP in flexible-dose trials. Our results suggest that flexible titration as needed, i.e., considering the presence of ADHD symptoms, and tolerated, i.e., considering the presence of dose-limiting AEs, to higher doses of stimulants is associated with both improved efficacy and acceptability because practitioners can increase/reduce doses based on control of ADHD symptoms/dose-limiting AEs. Although fixed-dose trials that are required by the FDA are valuable to characterize dose-dependency, they may underestimate the true potential benefit of trialing dose-increases of stimulants in clinical practice by not allowing dose adjustment based on response and tolerability. Additional research is required to investigate potential long-term effects of using high doses of stimulants in clinical practice.

Acute Tolerability of Methylphenidate in Treatment-Naïve Children with ADHD: An Analysis of Naturalistically Collected Data from Clinical Practice

OBJECTIVES

The acute tolerability of methylphenidate (MPH) in children with attention-deficit/hyperactivity disorder (ADHD) has been studied mainly in research samples. Taking advantage of the mandatory test-dose procedure required for starting MPH in Italy, this study aimed to assess the incidence of intolerable adverse events after initial exposure to MPH in routine clinical practice.

METHODS

The medical records of 480 consecutively treated, previously drug-naïve children and adolescents with ADHD (90% male, mean age 10.6 ± 3.0 years) were retrospectively analyzed. All children received an initial single dose of MPH immediate release (5 or 10 mg) followed by a 4-hour direct medical observation. Heart rate and blood pressure were measured at dosing and 1, 2, and 3 hours afterwards. If the first dose was well tolerated, the child continued treatment with MPH 5-20 mg daily, and was reassessed a week later.

RESULTS

Eleven patients (2.3%, 95% CI 1.1-4.1) interrupted treatment within a week of initiation because of the following adverse events: irritability (n = 3), tics worsening (n = 3), reduced appetite (n = 1), enuresis (n = 1), hallucinations (n = 1), hyperfocus (n = 1), and 'rebound' behavioral worsening (n = 1). The most common adverse events were reduced appetite (20%), irritability (14.2%), headache (10.6%), sleep problems (9.4%), stomachache (9.4%), and tics (5%). Intellectual disability increased the risk of any adverse event in general and of irritability in particular. No cardiovascular symptom was clinically reported. However, routine assessments of vital signs during the first 3 hours after the first dose of MPH showed that 9% of the children had a 20% increase in heart rate, 8.8% had a 20% increase in diastolic blood pressure and 4.5% had a 20% increase in systolic blood pressure. Of these, 25.2% still had an elevated heart rate 1 week later.

CONCLUSIONS

Among stimulant-naïve children in clinical practice, the incidence of acute MPH intolerance can be estimated to be between 1.2 and 4.1%. An asymptomatic elevation in cardiovascular parameters can be observed in about 1 out of 10 children and warrants monitoring during ongoing treatment.

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.

ADHD: Reviewing the Causes and Evaluating Solutions

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder in which patients present inattention, hyperactivity, and impulsivity. The etiology of this condition is diverse, including environmental factors and the presence of variants of some genes. However, a great diversity exists among patients regarding the presence of these ADHD-associated factors. Moreover, there are variations in the reported neurophysiological correlates of ADHD. ADHD is often treated pharmacologically, producing an improvement in symptomatology, albeit there are patients who are refractory to the main pharmacological treatments or present side effects to these drugs, highlighting the importance of developing other therapeutic options. Different non-pharmacological treatments are in this review addressed, finding diverse results regarding efficacy. Altogether, ADHD is associated with different etiologies, all of them producing changes in brain development, leading to the characteristic symptomatology of this condition. Given the heterogeneous etiology of ADHD, discussion is presented about the convenience of personalizing ADHD treatment, whether pharmacological or non-pharmacological, to reach an optimum effect in the majority of patients. Approaches to personalizing both pharmacological therapy and neurofeedback are presented.

Suicidal and non-suicidal self-injurious behaviour in patients with bipolar disorder and comorbid attention deficit hyperactivity disorder after initiation of central stimulant treatment: a mirror-image study based on the LiSIE retrospective cohort

BACKGROUND

Currently, our understanding regarding treatment of adult attention deficit hyperactivity disorder (ADHD) co-occurring with bipolar disorder (BD) remains limited. The aim of this study was to evaluate the impact of central stimulant (CS) treatment on suicidal and non-suicidal self-injurious behaviour in patients with a pre-existing diagnosis of BD or schizoaffective disorder (SZD). Specifically, we tested the hypothesis that CS treatment significantly decreased the number of suicide attempts and non-suicidal self-injury events.

METHODS

A mirror-image study in patients with a dual diagnosis of BD or SZD and ADHD, comparing suicide attempts and non-suicidal self-injury events within 6 months and 2 years before and after CS initiation. This study was part of a retrospective cohort study (LiSIE) into effects and side-effects of lithium for maintenance treatment of BD as compared with other mood stabilisers.

RESULTS

Of 1564 eligible patients, 206 patients met the inclusion criteria. Within the 6 months after CS initiation, suicide attempts and non-suicidal self-injury events decreased significantly, both in terms of numbers of patients having such events (p = 0.013) and numbers of events experienced (p = 0.004). These effects were preserved 2 years after CS initiation.

CONCLUSIONS

CS treatment may reduce the risk of suicide attempts and non-suicidal self-injury events in patients with a dual diagnosis of BD or SZD and ADHD. Based on our findings, clinicians should not withhold CS treatment from patients with concomitant ADHD for fear of deterioration of the underlying BD. However, to minimise the risk of manic episodes concomitant mood stabiliser treatment and close monitoring remains warranted.

Neurological and psychiatric adverse effects of long-term methylphenidate treatment in ADHD: A map of the current evidence

Methylphenidate (MPH), the most common medication for children with Attention Deficit/Hyperactivity Disorder (ADHD) in many countries, is often prescribed for long periods of time. Any long-term psychotropic treatment in childhood raises concerns about possible adverse neurological and psychiatric outcomes. We aimed to map current evidence regarding neurological and psychiatric outcomes, adverse or beneficial, of long-term MPH (> 1 year) treatment in ADHD. We coded studies using a "traffic light" system: Green: safe/favours MPH; Amber: warrants caution; Red: not safe/not well-tolerated. Un-categorisable study findings were coded as "Unclear". Although some evidence suggests an elevated risk of psychosis and tics, case reports describe remission on discontinuation. Several studies suggest that long-term MPH may reduce depression and suicide in ADHD. Evidence suggests caution in specific groups including pre-school children, those with tics, and adolescents at risk for substance misuse. We identified a need for more studies that make use of large longitudinal databases, focus on specific neuropsychiatric outcomes, and compare outcomes from long-term MPH treatment with outcomes following shorter or no pharmacological intervention.

Evaluation of dietary intake in children and college students with and without attention-deficit/hyperactivity disorder

Objectives: To evaluate dietary intake among individuals with and without attention-deficit hyperactivity disorder (ADHD), to evaluate the likelihood that those with ADHD have inadequate intakes. Methods: Children, 7-12 years old, with (n = 23) and without (n = 22) ADHD, and college students, 18-25 years old, with (n = 21) and without (n = 30) ADHD comprised the samples. Children's dietary intake was assessed by a registered dietitian using 24-hour recalls over 3 days. College students kept a detailed food record over three days. Dietary information for both groups was entered into the Nutrition Data Systems for Research database, and output was analyzed using SAS 9.4. Nutrient analyses included the Healthy Eating Index-2010, Micronutrient Index (as a measure of overall micronutrient intake), and individual amino acids necessary for neurotransmission. Logistic regression was used to model the association of nutrient intake with ADHD. Models were adjusted for age, sex, IQ (or GPA), and energy intake (or total protein intake) as appropriate. Significance was evaluated at P = 0.05, and using the Benjamini-Hochberg corrected P-value for multiple comparisons. Results: No evidence existed for reduced nutrient intake among those with ADHD compared to controls in either age group. Across both groups, inadequate intakes of vitamin D and potassium were reported in 95% of participants. Children largely met nutrient intake guidelines, while college students failed to meet these guidelines for nine nutrients. In regards to amino acid intake in children, an increased likelihood of having ADHD was associated with higher consumption of aspartate, OR = 12.61 (P = 0.01) and glycine OR = 11.60 (P = 0.05); and a reduced likelihood of ADHD with higher intakes of glutamate, OR = 0.34 (P = 0.03). Among young adults, none of the amino acids were significantly associated with ADHD, though glycine and tryptophan approached significance. Discussion: Results fail to support the hypothesis that ADHD is driven solely by dietary micronutrient inadequacy. However, amino acids associated with neurotransmission, specifically those affecting glutamatergic neurotransmission, differed by ADHD status in children. Amino acids did not reliably vary among college students. Future larger scale studies are needed to further examine whether or not dietary intake of amino acids may be a modulating factor in ADHD.

NURR1 deficiency is associated to ADHD-like phenotypes in mice

The transcription factor NURR1 regulates the dopamine (DA) signaling pathway and exerts a critical role in the development of midbrain dopaminergic neurons (mDA). NURR1 alterations have been linked to DA-associated brain disorders, such as Parkinson's disease and schizophrenia. However, the association between NURR1 defects and the attention-deficit hyperactivity disorder (ADHD), a DA-associated brain disease characterized by hyperactivity, impulsivity and inattention, has never been demonstrated. To date, a comprehensive murine model of ADHD truly reflecting the whole complex human psychiatric disorder still does not exist. NURR1-knockout (NURR1-KO) mice have been reported to exhibit increased spontaneous locomotor activity, but their complete characterization is still lacking. In the present study a wide-ranging test battery was used to perform a comprehensive analysis of the behavioral phenotype of the male NURR1-KO mice. As a result, their hyperactive phenotype was confirmed, while their impulsive behavior was reported for the first time. On the other hand, no anxiety and alterations in motor coordination, sociability and memory were observed. Also, the number of mDA expressing tyrosine hydroxylase, a rate-limiting enzyme of catecholamines biosynthesis, and DA level in brain were not impaired in NURR1-KO mice. Finally, hyperactivity has been shown to be recovered by treatment with methylphenidate, the first line psychostimulant drug used for ADHD. Overall, our study suggests that the NURR1 deficient male mouse may be a satisfactory model to study some ADHD behavioral phenotypes and to test the clinical efficacy of potential therapeutic agents.

The Effect of Methylphenidate and Atomoxetine on Heart Rate and Systolic Blood Pressure in Young People and Adults with Attention-Deficit Hyperactivity Disorder (ADHD): Systematic Review, Meta-Analysis, and Meta-Regression

Objectives: This meta-analysis aims to study the effects of atomoxetine and methylphenidate on heart rate (HR), systolic blood pressure (SBP), and a number of adverse cardiac events on patients receiving treatment for attention-deficit hyperactive disorder (ADHD) in comparison to placebo and between atomoxetine and methylphenidate. Methods: We searched the following databases: PubMed, EMBASE, and ScienceDirect. Meta-analysis was performed on studies that examined the relationships between methylphenidate or atomoxetine and HR, SBP, as well as a number of adverse cardiac events. These studies were either placebo-controlled or comparison studies between methylphenidate and atomoxetine. Meta-regression identified patient- and treatment-related factors that may contribute to heterogeneity. Results: Twenty-two studies were included and the total number of participants was 46,107. Children/adolescents and adults treated with methylphenidate had more significant increases in post- vs. pre-treatment HR (p < 0.001) and SBP (p < 0.001) than those treated by placebo. Children and adolescents treated with atomoxetine had more significant increases post- vs. pre-treatment HR (p = 0.025) and SBP (p < 0.001) than those treated with methylphenidate. Meta-regression revealed mean age of participants, mean dose, and duration of atomoxetine and methylphenidate as significant moderators that explained heterogeneity. There were no differences in the number of adverse cardiac events between participants with methylphenidate treatment and placebo or atomoxetine. Conclusions: Children/adolescents and adults treated with methylphenidate resulted in significant increases in post- vs. pre-treatment HR and SBP as compared to placebo. Similarly, children and adolescents treated with atomoxetine had significant increases in post- vs. pre-treatment HR and SBP than those treated with methylphenidate. These findings have potential implications for continuous monitoring of HR and SBP throughout the course of treatment although the risk for adverse cardiac events were insignificant.

Hallucinations and other psychotic symptoms in response to methylphenidate in children and adolescents with attention-deficit/hyperactivity disorder: a Cochrane systematic review with meta-analysis and trial sequential analysis. Scand J Child Adolesc Psychiatr Psychol 2018;6:52-71. [PMID: 33520751 PMCID: PMC7750702 DOI: 10.21307/sjcapp-2018-003]

BACKGROUND

There is little evidence in the literature on the association between methylphenidate treatment and psychotic symptoms in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

OBJECTIVE

We examine the occurrence of psychotic symptoms during methylphenidate treatment of children and adolescents with ADHD. The data arise from our two Cochrane systematic reviews on methylphenidate, reported elsewhere.

METHODS

Electronic databases were searched up to January 2016 (for observational studies) and March 2017 (for randomized trials). We summarized data as risk ratios and pooled prevalences. Trial Sequential Analysis was used to control for random errors. We assessed the risk of bias and the quality of evidence according to Cochrane guidelines.

RESULTS

Ten randomized trials (1103 participants), 17 non-randomized studies (76,237 participants) and 12 patient reports or series (18 patients) were identified. In the randomized trials, there was no significant difference in the risk of developing psychotic symptoms [10 of 654 (pooled prevalence, 2.5%) methylphenidate versus 1 of 508 (pooled prevalence, 1.7%) placebo patients; risk ratio, 2.07; 95% confidence interval, 0.58 to 7.35]. Nine of 10 trials had a high risk of bias, and according to the Trial Sequential Analysis, the required information size was not achieved, that is, the meta-analysis was considerably underpowered. There were 873 instances of psychotic symptoms in the non-randomized studies among 55,603 participants (pooled prevalence, 1.2%; 95% confidence interval, 0.7 to 2.4). In the comparative cohort study, methylphenidate significantly increased the risk for any psychotic disorder by 36% (risk ratio, 1.36; 95% confidence interval, 1.17 to 1.57). The overall risk of bias was rated as critical for this study.

CONCLUSIONS

Because of sparse data and low quality of evidence, we cannot confirm or refute whether methylphenidate increases the risk of psychotic symptoms in children and adolescents with ADHD. This possible adverse event may affect 1.1% to 2.5%, and physicians, patients and caregivers should be aware of this to ensure proper treatment in case of occurrence during methylphenidate treatment.

Methylphenidate for attention deficit hyperactivity disorder (ADHD) in children and adolescents - assessment of adverse events in non-randomised studies

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in childhood. The psychostimulant methylphenidate is the most frequently used medication to treat it. Several studies have investigated the benefits of methylphenidate, showing possible favourable effects on ADHD symptoms, but the true magnitude of the effect is unknown. Concerning adverse events associated with the treatment, our systematic review of randomised clinical trials (RCTs) demonstrated no increase in serious adverse events, but a high proportion of participants suffered a range of non-serious adverse events.

OBJECTIVES

To assess the adverse events associated with methylphenidate treatment for children and adolescents with ADHD in non-randomised studies.

SEARCH METHODS

In January 2016, we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 12 other databases and two trials registers. We also checked reference lists and contacted authors and pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included non-randomised study designs. These comprised comparative and non-comparative cohort studies, patient-control studies, patient reports/series and cross-sectional studies of methylphenidate administered at any dosage or formulation. We also included methylphenidate groups from RCTs assessing methylphenidate versus other interventions for ADHD as well as data from follow-up periods in RCTs. Participants had to have an ADHD diagnosis (from the 3rd to the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders or the 9th or 10th edition of theInternational Classification of Diseases, with or without comorbid diagnoses. We required that at least 75% of participants had a normal intellectual capacity (intelligence quotient of more than 70 points) and were aged below 20 years. We excluded studies that used another ADHD drug as a co-intervention.

DATA COLLECTION AND ANALYSIS

Fourteen review authors selected studies independently. Two review authors assessed risk of bias independently using the ROBINS-I tool for assessing risk of bias in non-randomised studies of interventions. All review authors extracted data. We defined serious adverse events according to the International Committee of Harmonization as any lethal, life-threatening or life-changing event. We considered all other adverse events to be non-serious adverse events and conducted meta-analyses of data from comparative studies. We calculated meta-analytic estimates of prevalence from non-comparative cohorts studies and synthesised data from patient reports/series qualitatively. We investigated heterogeneity by conducting subgroup analyses, and we also conducted sensitivity analyses.

MAIN RESULTS

We included a total of 260 studies: 7 comparative cohort studies, 6 of which compared 968 patients who were exposed to methylphenidate to 166 controls, and 1 which assessed 1224 patients that were exposed or not exposed to methylphenidate during different time periods; 4 patient-control studies (53,192 exposed to methylphenidate and 19,906 controls); 177 non-comparative cohort studies (2,207,751 participants); 2 cross-sectional studies (96 participants) and 70 patient reports/series (206 participants). Participants' ages ranged from 3 years to 20 years. Risk of bias in the included comparative studies ranged from moderate to critical, with most studies showing critical risk of bias. We evaluated all non-comparative studies at critical risk of bias. The GRADE quality rating of the evidence was very low.Primary outcomesIn the comparative studies, methylphenidate increased the risk ratio (RR) of serious adverse events (RR 1.36, 95% confidence interval (CI) 1.17 to 1.57; 2 studies, 72,005 participants); any psychotic disorder (RR 1.36, 95% CI 1.17 to 1.57; 1 study, 71,771 participants); and arrhythmia (RR 1.61, 95% CI 1.48 to 1.74; 1 study, 1224 participants) compared to no intervention.In the non-comparative cohort studies, the proportion of participants on methylphenidate experiencing any serious adverse event was 1.20% (95% CI 0.70% to 2.00%; 50 studies, 162,422 participants). Withdrawal from methylphenidate due to any serious adverse events occurred in 1.20% (95% CI 0.60% to 2.30%; 7 studies, 1173 participants) and adverse events of unknown severity led to withdrawal in 7.30% of participants (95% CI 5.30% to 10.0%; 22 studies, 3708 participants).Secondary outcomesIn the comparative studies, methylphenidate, compared to no intervention, increased the RR of insomnia and sleep problems (RR 2.58, 95% CI 1.24 to 5.34; 3 studies, 425 participants) and decreased appetite (RR 15.06, 95% CI 2.12 to 106.83; 1 study, 335 participants).With non-comparative cohort studies, the proportion of participants on methylphenidate with any non-serious adverse events was 51.2% (95% CI 41.2% to 61.1%; 49 studies, 13,978 participants). These included difficulty falling asleep, 17.9% (95% CI 14.7% to 21.6%; 82 studies, 11,507 participants); headache, 14.4% (95% CI 11.3% to 18.3%; 90 studies, 13,469 participants); abdominal pain, 10.7% (95% CI 8.60% to 13.3%; 79 studies, 11,750 participants); and decreased appetite, 31.1% (95% CI 26.5% to 36.2%; 84 studies, 11,594 participants). Withdrawal of methylphenidate due to non-serious adverse events occurred in 6.20% (95% CI 4.80% to 7.90%; 37 studies, 7142 participants), and 16.2% were withdrawn for unknown reasons (95% CI 13.0% to 19.9%; 57 studies, 8340 participants).

AUTHORS' CONCLUSIONS

Our findings suggest that methylphenidate may be associated with a number of serious adverse events as well as a large number of non-serious adverse events in children and adolescents, which often lead to withdrawal of methylphenidate. Our certainty in the evidence is very low, and accordingly, it is not possible to accurately estimate the actual risk of adverse events. It might be higher than reported here.Given the possible association between methylphenidate and the adverse events identified, it may be important to identify people who are most susceptible to adverse events. To do this we must undertake large-scale, high-quality RCTs, along with studies aimed at identifying responders and non-responders.

Methylphenidate dose optimization for ADHD treatment: review of safety, efficacy, and clinical necessity

Attention-deficit/hyperactivity disorder (ADHD) is a chronic psychiatric disorder characterized by hyperactivity and/or inattention and is often associated with a substantial impact on psychosocial functioning. Methylphenidate (MPH), a central nervous system stimulant, is commonly used for pharmacological treatment of adults and children with ADHD. Current practice guidelines recommend optimizing MPH dosage to individual patient needs; however, the clinical benefits of individual dose optimization compared with fixed-dose regimens remain unclear. Here we review the available literature on MPH dose optimization from clinical trials and real-world experience on ADHD management. In addition, we report safety and efficacy data from the largest MPH modified-release long-acting Phase III clinical trial conducted to examine benefits of dose optimization in adults with ADHD. Overall, MPH is an effective ADHD treatment with a good safety profile; data suggest that dose optimization may enhance the safety and efficacy of treatment. Further research is required to establish the extent to which short-term clinical benefits of MPH dose optimization translate into improved long-term outcomes for patients with ADHD.

Sleep Problems in Children with Attention Deficit/Hyperactivity Disorder: Current Status of Knowledge and Appropriate Management

Attention deficit hyperactivity disorder (ADHD) affects approximately 5 % of children and adolescents, and sleep problems are common in these patients. There is growing evidence informing the significant importance of sleep problems in youth with ADHD. The sleep problems in children with ADHD include specific sleep disorders and sleep disturbances due to comorbid psychiatric disorders or ADHD medications. The specific sleep disorders of ADHD children include behaviorally based insomnia, sleep-disordered breathing, and restless legs syndrome/periodic limb movement disorder. Current practices on the management of sleep problems for ADHD children are based mostly on expert consensus, whereas more evidence-based literature can be found only recently. Assessment of the sleep conditions in ADHD children before initiation of pharmacotherapy is the currently recommended guideline, and good sleep hygiene can be considered as the first-line treatment option. In addition to modifying the dose regimens, formulation, or alternative stimulants when sleep problems are encountered in ADHD children, atomoxetine, once daily guanfacine extended release, and melatonin are potential choices for ADHD children with more severe sleep problems. In this review, we aimed to provide the most updated information, preferably based on meta-analyses, systemic review, and randomized controlled trials published in the latest 3 years, in order to be clinically useful for practitioners and clinicians.