Amfetamine and methylphenidate medications for attention-deficit/hyperactivity disorder: complementary treatment options

Stimulant medication and symptom interrelations in children, adolescents and adults with attention-deficit/hyperactivity disorder

Stimulant medication is effective in alleviating overall symptom severity of attention-deficit/hyperactivity disorder (ADHD), yet interindividual variability in treatment response and tolerability still exists. While network analysis has identified differences in ADHD symptom relations, the impact of stimulant medication remains unexplored. Increased understanding of this association could provide valuable insights for optimizing treatment approaches for individuals with ADHD. In this study, we compared and characterized ADHD symptom networks (including 18 ADHD symptoms) between stimulant-treated (n = 348) and untreated (n = 70) individuals with ADHD and non-ADHD controls (NACs; n = 444). Moreover, we compared symptom networks between subgroups defined by their stimulant treatment trajectory (early-and-intense use, late-and-moderate use). Stimulant-treated individuals with ADHD showed stronger associations between symptoms, compared with untreated individuals with ADHD and NACs. We found no differences in symptom networks between the stimulant treatment trajectory subgroups. Prospective longitudinal studies are needed to disentangle whether the identified differences stem from treatment or pre-existing factors.

Association Between Single-Dose and Longer Term Clinical Response to Stimulants in Attention-Deficit/Hyperactivity Disorder: A Systematic Review of Randomized Controlled Trials

Objectives: Stimulants, such as methylphenidate (MPH) and amphetamines, represent the first-line pharmacological option for attention-deficit/hyperactivity disorder (ADHD). Randomized controlled trials (RCTs) have demonstrated beneficial effects at a group level but could not identify characteristics consistently associated with varying individual response. Thus, more individualized approaches are needed. Experimental studies have suggested that the neurobiological response to a single dose is indicative of longer term response. It is unclear whether this also applies to clinical measures. Methods: We carried out a systematic review of RCTs testing the association between the clinical response to a single dose of stimulants and longer term improvement. Potentially suitable single-dose RCTs were identified from the MED-ADHD data set, the European ADHD Guidelines Group RCT Data set (https://med-adhd.org/), as updated on February 1, 2024. Quality assessment was carried out using the Cochrane Risk of Bias (RoB) 2.0 tool. Results: A total of 63 single-dose RCTs (94% testing MPH, 85% in children) were identified. Among these, only a secondary analysis of an RCT tested the association between acute and longer term clinical response. This showed that the clinical improvement after a single dose of MPH was significantly associated with symptom improvement after a 4-week MPH treatment in 46 children (89% males) with ADHD. The risk of bias was rated as moderate. A further RCT used near-infrared spectroscopy, thus did not meet the inclusion criteria, and reported an association between brain changes under a single-dose and longer term clinical response in 22 children (82% males) with ADHD. The remaining RCTs only reported single-dose effects on neuropsychological, neuroimaging, or neurophysiological measures. Conclusion: This systematic review highlighted an important gap in the current knowledge. Investigating how acute and long-term response may be related can foster our understanding of stimulant mechanism of action and help develop stratification approaches for more tailored treatment strategies. Future studies need to investigate potential age- and sex-related differences.

The effect of a single dose of methylphenidate on attention in children and adolescents with ADHD and comorbid Oppositional Defiant Disorder

The co-occurrence Oppositional Defiant Disorder (ODD) in children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) has been associated to difficulties in regulating adverse states, elevated functional impairment, deficits in Executive Functions and high risk for psychopathology. Recent studies have shown that ODD is a negative predictor of a positive response to methylphenidate (MPH) treatment for ADHD symptoms in children and adolescents and that patients with a diagnosis of comorbid ADHD and ODD are less likely to respond favorably to pharmacological treatment with MPH. We conducted a naturalistic study to understand the clinical characteristics of drug-naïve children and adolescents with ADHD that influence the response to MPH by measuring the effect on attention. Specifically, we investigated whether a single dose of MPH differently affects the performance of 53 children and adolescents with ADHD with or without ODD comorbidity. In addition, participant characteristics such as symptom severity, functional impairment, and associated behavioral and emotional symptoms at baseline were examined to better understand what aspects affect the response to MPH. We found that a single dose of MPH improved the attention of children and adolescents with ADHD without ODD more than those with comorbid ADHD and ODD, resulting in reduced reaction times. Our findings indicated that children and adolescents with comorbid ADHD and ODD and those with ADHD alone did not exhibit differences in measures of attention prior to taking MPH, nor in demographic variables (age, intelligence quotient, gender), clinical characteristics related to symptom severity, and adaptive behaviors. However, we observed differences between the two groups in certain behavioral aspects, including the Dysregulation Profile and disruptive behaviors. Assessing symptoms in combination with the presence of ADHD can be beneficial in determining which individuals would derive the greatest benefits from treatment.

Psychostimulants prescribed to children for ADHD following distal radius fractures significantly reduce bone density as a function of duration

Methylphenidate and mixed amphetamine salts (MAS) are psychostimulant medications widely prescribed for various psychiatric disorders. Although these medications are known to adversely impact bone mineral content and density, as well as biomechanical integrity during skeletal development in rats, their effect on bone density in children remains largely unknown. The primary aim of this work was to investigate the effects of methylphenidate and MAS on bone density following distal radius fractures in pediatric populations, and secondarily assess any impact on healing. The retrospective case-control study was designed to assess fracture healing in patients treated with stimulant drugs and matched controls. For the primary outcome, X-rays ( n  = 188) were evaluated using an optical density image analysis technique to compare bone density throughout the bone healing process. Results showed that methylphenidate and MAS significantly reduced bone healing by approximately 20% following distal radius fractures in these children. The data also suggested that duration of psychostimulant use played a role in bone healing; the longer the treatment (1-5 years), the lower the bone density was observed (by approximately 52%) as compared to controls (no medication). However, subjects taking these drugs for longer than 5 years did not show a significant difference. Our results suggested that children taking psychostimulants for up to 5 years had slower bone healing following distal radius fractures. Orthopedic surgeons planning elective surgeries should be cognizant of this as a potential issue in recovery after any elective bone procedures and preoperatively optimize bone health as well as counsel patients and their families.

Differential Roles of Key Brain Regions: Ventral Tegmental Area, Locus Coeruleus, Dorsal Raphe, Nucleus Accumbens, Caudate Nucleus, and Prefrontal Cortex in Regulating Response to Methylphenidate: Insights from Neuronal and Behavioral Studies in Freely Behaving Rats

A total of 3102 neurons were recorded before and following acute and chronic methylphenidate (MPD) administration. Acute MPD exposure elicits mainly increases in neuronal and behavioral activity in dose-response characteristics. The response to chronic MPD exposure, as compared to acute 0.6, 2.5, or 10.0 mg/kg MPD administration, elicits electrophysiological and behavioral sensitization in some animals and electrophysiological and behavioral tolerance in others when the neuronal recording evaluations were performed based on the animals' behavioral responses, or amount of locomotor activity, to chronic MPD exposure. The majority of neurons recorded from those expressing behavioral sensitization responded to chronic MPD with further increases in firing rate as compared to the initial MPD responses. The majority of neurons recorded from animals expressing behavioral tolerance responded to chronic MPD with decreases in their firing rate as compared to the initial MPD exposures. Each of the six brain areas studied-the ventral tegmental area, locus coeruleus, dorsal raphe, nucleus accumbens, prefrontal cortex, and caudate nucleus (VTA, LC, DR, NAc, PFC, and CN)-responds significantly (p < 0.001) differently to MPD, suggesting that each one of the above brain areas exhibits different roles in the response to MPD. Moreover, this study demonstrates that it is essential to evaluate neuronal activity responses to psychostimulants based on the animals' behavioral responses to acute and chronic effects of the drug from several brain areas simultaneously to obtain accurate information on each area's role in response to the drug.

Improving Methylphenidate Titration in Children with Attention-Deficit/Hyperactivity Disorder (ADHD): A Randomized Controlled Trial Using Placebo-Controlled Titration Implemented in Clinical Practice

BACKGROUND AND OBJECTIVES

Concerns exist regarding the rising use of methylphenidate. A double-blind, placebo-controlled methylphenidate titration (PCT) for children with attention-deficit/hyperactivity disorder (ADHD) has shown potential to improve titration (i.e., detection of placebo responders and larger ADHD symptom improvement) in experimental settings. This study aims to determine if these advantages can be transferred to clinical settings.

METHOD

Children (aged 5-13 years) with an ADHD diagnosis and an indication to start methylphenidate (MPH) treatment were recruited. Participants were randomized to PCT or care as usual (CAU) in a 1:1 ratio followed by a 7-week randomized controlled trial (T1) and 6-month, naturalistic, open-label follow-up (T2). Parents, teachers, and physicians rated ADHD symptoms, ADHD medication use, MPH dosing, and treatment satisfaction using questionnaires.

RESULTS

A total of 100 children were enrolled and randomized to PCT (n = 49) or CAU (n = 51). In the PCT group, we found 8.2% placebo responders, 16.3% non-responders, and 65.3% responders to MPH. With PCT compared with CAU, a significantly larger number of children discontinued MPH (T1: 24.5 vs 5.9%, p = 0.009; T2: 41.7 vs 10.4%, p < 0.001) and refrained from using other pharmacological treatment (T1: 20.4 vs 3.9%, p = 0.013; T2: 20.83 vs 6.25%, p = 0.002). At both timepoints, there were no significant differences between the groups in the average dose of MPH, ADHD symptoms, or treatment satisfaction.

CONCLUSIONS

PCT can be used to improve detection of children who do not benefit from MPH, and may therefore potentially reduce overtreatment of ADHD with MPH.

Viloxazine extended-release capsules as an emerging treatment for attention-deficit/hyperactivity disorder in children and adolescents

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention and/or hyperactivity and impulsivity. Viloxazine extended-release (ER) capsules (Qelbree®) is a US Food and Drug Administration-approved nonstimulant treatment option for children, adolescents, and adults with ADHD.

AREAS COVERED

This review manuscript summarizes the neurobiology of ADHD and currently available treatment options before discussing viloxazine pharmacology, efficacy, safety, and tolerability data from phase II and III trials in children and adolescents (6-17 years old). Viloxazine clinical efficacy has also been further demonstrated by post hoc analyses of pediatric clinical trial results.

EXPERT OPINION

Current stimulant and nonstimulant treatments for ADHD may be suboptimal given low response rates and that tolerability issues are frequently experienced. Preclinical and clinical evidence has implicated both the role of catecholamine and serotonin signaling in the pathophysiology of ADHD and the pharmacologic effect of viloxazine on these critical neurotransmitter systems. With a relatively rapid onset of action, sustained symptom improvement, and clinical benefit in ADHD-associated impairments (functional and social), viloxazine ER represents a novel and emerging ADHD treatment option.

Switch to Lisdexamfetamine in the Treatment of Attention-Deficit Disorder at a Psychiatric Outpatient Clinic for School-Aged Children: A Danish Cohort Study

Objectives: This study aimed to examine switch from first-line methylphenidate (MPH) to lisdexamfetamine (LDX) in school-aged children with attention-deficit/hyperactivity disorder (ADHD). Methods: This is a retrospective observational study based on systematic review of patient records of all children (7-13 years) diagnosed with ADHD and referred to a Danish specialized outpatient clinic. The study included 394 children switching from MPH to LDX as either second-line or third-line treatment (atomoxetine [ATX] as second-line treatment) during the study period from April 1, 2013, to November 5, 2019. Results: One in five children switched from MPH to LDX at some point during the study period. The most frequent reasons for switching to LDX were adverse effects (AEs; 70.0% for MPH, 68.3% for ATX) and lack of efficiency (52.0% for MPH, 72.7% for ATX). Top five AEs of LDX were decreased appetite (62.4%), insomnia (28.7%), irritability/aggression (26.1%), weight decrease (21.1%), and mood swings (13.9%). MPH and LDX had similar AE profiles, yet most AEs were less frequent after switching to LDX. At the end of the study period, the majority were prescribed LDX as second-line rather than third-line treatment (86.1% in 2019). However, the likelihood of LDX as second-line treatment decreased with the number of psychiatric comorbidities, ADHD symptom severity as assessed by parents, and if AEs were a reason for MPH discontinuation. Among children observed for at least 1 year after initiation of LDX, 41.3% continued LDX treatment for a year or longer. LDX continuation was less likely if AEs were a reason for MPH discontinuation. Similarly to MPH and ATX, the most frequent reasons for LDX discontinuation were AEs (74.4%) and lack of efficiency (34.7%). Implications: The findings support LDX as an important option in the personalized treatment of children with ADHD and may support prescribers in the clinical decision-making on switching medication.

Inflammatory biotype of ADHD is linked to chronic stress: a data-driven analysis of the inflammatory proteome

The association between Attention Deficit Hyperactivity Disorder (ADHD) and low-grade inflammation has been explored in children but rarely in adults. Inflammation is characteristic of some, but not all, patients with ADHD and might be influenced by ADHD medication but also lifestyle factors including nutrition, smoking, and stress. It is also still unclear if any specific symptoms are related to inflammation. Therefore, we assessed 96 inflammatory proteins in a deeply phenotyped cohort of 126 adult ADHD participants with a stable medication status using OLINK technology. A data-based, unsupervised hierarchical clustering method could identify two distinct biotypes within the 126 ADHD participants based on their inflammatory profile: a higher inflammatory potential (HIP) and a lower inflammatory protein potential (LIP) group. Biological processes that differed strongest between groups were related to the NF-κB pathway, chemokine signaling, IL-17 signaling, metabolic alterations, and chemokine attraction. A comparison of sample characteristics revealed that the HIP group was more likely to have higher levels of chronic stress (p < 0.001), a higher clinical global impression scale score (p = 0.030), and a higher risk for suicide (p = 0.032). Medication status did not influence protein levels significantly (p ≥ 0.074), but psychotropic co-medication (p ≤ 0.009) did. In conclusion, our data suggest the presence of two distinct biotypes in adults with ADHD. Higher levels of inflammatory proteins in ADHD are linked to higher levels of chronic perceived stress in a linear fashion. Further research on inflammation in adults with ADHD should take stress levels into account.

Methylphenidate induces a different response in the dorsal raphe as compared to ventral tegmental area and locus coeruleus: behavioral and concomitant neuronal recordings in adult rats

Methylphenidate (MPD) is a psychostimulant used to treat attention deficit hyperactivity disorder. MPD exerts its neurocognitive effects through increasing concentrations of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in the neuronal synapse. This study recorded from adult freely behaving rats a total of 1170 neurons, 403 from the ventral tegmental area (VTA), 409 from locus coeruleus (LC), and 356 from dorsal raphe (DR) nucleus, which are the main sources of DA, NE, and 5-HT to the mesocorticolimbic circuitry, respectively. Electrophysiological and behavioral activities were recorded simultaneously following acute and repetitive (chronic) saline or 0.6, 2.5, or 10.0 mg/kg MPD. The uniqueness of this study is the evaluation of neuronal activity based on the behavioral response to chronic MPD. Animals received daily saline or MPD administration on experimental days 1-6 (ED1-6), followed by a 3-day wash-out period, and then MPD rechallenge on ED10. Each chronic MPD dose elicits behavioral sensitization in some animals, while in others, behavioral tolerance. Neuronal excitation following chronic MPD was observed in brains areas of animals exhibiting behavioral sensitization, while neuronal attenuation following chronic MPD was observed in those animals expressing behavioral tolerance. DR neuronal activity was most affected in response to acute and chronic MPD administration and responded differently compared to the neurons recorded from VTA and LC neurons at all doses. This suggests that although not directly related, DR and 5-HT are involved in the acute and chronic effects of MPD in adult rats, but exhibit a different role in response to MPD.

Dopamine, Norepinephrine and Serotonin Participate Differently in Methylphenidate Action in Concomitant Behavioral and Ventral Tegmental Area, Locus Coeruleus and Dorsal Raphe Neuronal Study in Young Rats

Methylphenidate (MPD), known as Ritalin, is a psychostimulant used to treat children, adults, and the elderly. MPD exerts its effects through increasing concentrations of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in the synaptic cleft. Concomitant behavioral and neuronal recording from the ventral tegmental area (VTA), locus coeruleus (LC), and from the dorsal raphe (DR) nucleus, which are the sources of DA, NE, and 5-HT to the mesocorticolimbic circuit, were investigated following acute and repetitive (chronic) saline, 0.6, 2.5, or 10.0 mg/kg MPD. Animals received daily saline or MPD administration on experimental days 1 to 6 (ED1-6), followed by a 3-day washout period and MPD rechallenge on ED10. Each chronic MPD dose elicits behavioral sensitization in some animals while inducing behavioral tolerance in others. The uniqueness of this study is in the evaluation of neuronal activity based on the behavioral response to chronic MPD. Neuronal excitation was observed mainly in brain areas of animals exhibiting behavioral sensitization, while neuronal attenuation following chronic MPD was observed in animals expressing behavioral tolerance. Different ratios of excitatory/inhibitory neuronal responses were obtained from the VTA, LC, or DR following chronic MPD. Thus, each brain area responds differently to each MPD dose used, suggesting that DA, NE, and 5-HT in the VTA, LC, and DR exert different effects.

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.

The combination of atomoxetine and dronabinol for the treatment of obstructive sleep apnea: a dose-escalating, open-label trial

STUDY OBJECTIVES

The potential sedative effect of dronabinol and the high expression of cannabinoid receptors on the hypoglossal motor nuclei makes this agent a good candidate for obstructive sleep apnea (OSA) pharmacotherapy to be tested with atomoxetine, a noradrenergic reuptake inhibitor that reduced OSA severity in combination with oxybutynin. Here we tested the effect of atomoxetine 80 mg plus dronabinol (Ato-Dro) at 2 different doses (5 and 10 mg) vs. baseline and atomoxetine alone in a 2-center, open-label, dose-escalating trial. The primary outcome was the effect of Ato-Dro vs. baseline on OSA severity (apnea-hypopnea index, hypopneas associated with 4% oxygen desaturation). Safety of the combination and self-reported outcomes were also assessed.

METHODS

Fifteen patients with OSA received progressively increasing Ato-Dro doses (dose escalation was performed every week, starting from Ato-Dro 40-2.5 mg, then 80-5 mg and finally 80-10 mg). A clinical, in-lab polysomnography was performed at baseline, on Ato-Dro 80-5 and Ato-Dro 80-10 mg.

RESULTS

Ato-Dro 80-10 mg did not significantly reduce apnea-hypopnea index, hypopneas associated with 4% oxygen desaturation, and hypoxic burden and yielded limited clinical benefit vs. baseline and atomoxetine alone. However, Ato-Dro 80-5 mg did improve OSA severity (Δapnea-hypopnea index = 8.3[0.3, 16.3] events/h; mean [confidence interval]; Δhypoxic burden = 37.7[12.5, 62.7] %min/h) and multiple self-reported outcomes vs. baseline and/or atomoxetine alone. Ato-Dro administration was characterized by several potentially harmful side effects and treatment discontinuation in 1/3 of cases.

CONCLUSIONS

Ato-Dro 80-5 mg might be useful to reduce OSA severity and lead to self-reported improvement in those who could tolerate the combination. However, given the numerous side effects and the exploratory nature of this open-label study, our results warrant further validation in larger trials.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Study for Efficacy and Dose Escalation of AD313 + Atomoxetine (SEED) (SEED); URL: https://clinicaltrials.gov/ct2/show/NCT05101122; Identifier: NCT05101122.

CITATION

Messineo L, Norman D, Ojile J. The combination of atomoxetine and dronabinol for the treatment of obstructive sleep apnea: a dose-escalating, open-label trial. J Clin Sleep Med. 2023;19(7):1183-1190.

Machine learning in attention-deficit/hyperactivity disorder: new approaches toward understanding the neural mechanisms

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent and heterogeneous neurodevelopmental disorder in children and has a high chance of persisting in adulthood. The development of individualized, efficient, and reliable treatment strategies is limited by the lack of understanding of the underlying neural mechanisms. Diverging and inconsistent findings from existing studies suggest that ADHD may be simultaneously associated with multivariate factors across cognitive, genetic, and biological domains. Machine learning algorithms are more capable of detecting complex interactions between multiple variables than conventional statistical methods. Here we present a narrative review of the existing machine learning studies that have contributed to understanding mechanisms underlying ADHD with a focus on behavioral and neurocognitive problems, neurobiological measures including genetic data, structural magnetic resonance imaging (MRI), task-based and resting-state functional MRI (fMRI), electroencephalogram, and functional near-infrared spectroscopy, and prevention and treatment strategies. Implications of machine learning models in ADHD research are discussed. Although increasing evidence suggests that machine learning has potential in studying ADHD, extra precautions are still required when designing machine learning strategies considering the limitations of interpretability and generalization.

Trends in amphetamine prescriptions given at discharge in emergency departments: A national analysis (2012-2019)

OBJECTIVES

In parallel with the opioid epidemic, there has been a resurgence in abuse, medical complications, and deaths related to amphetamines. The opioid epidemic began with increasing rates of prescription products that evolved overtime to include heroin and more recently, fentanyl analogues. Current trends in amphetamine prescriptions are less well described. We sought to determine if there has been a change in amphetamine prescriptions given at discharge in U.S. emergency departments (EDs) in recent years.

METHODS

We conducted a retrospective review of data provided by the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2012 to 2019. We computed total number of visits that were given amphetamine prescriptions (amphetamine salts, methylphenidate derivatives, and dexmethylphenidate) at discharge for each year. We computed the total number and rate of visits (of all ED visits) that had both amphetamines and opioids prescribed at discharge over the years. We computed data normality using Shapiro Wilke's test and used descriptive statistics such as mean to describe the data distribution as applicable. We used spearman's rho (SR) or pearson's correlation (PC) as applicable to describe trends in data. All p-values were one-tailed and were reported at a 0.05 significance level. All analyses were conducted in IBM SPSS version 28.

RESULTS/FINDINGS

From 2012 to 2019, there were an estimated 817,895 ED visits where an amphetamine prescription was given at discharge, with an overall strong increase in rate over time (SR = 0.71, p = 0.02). At the beginning of the study period (2012) there were 83,503 (0.06%) visits and in 2019 there were 186,539 (0.12%) visits (123% absolute increase). On average, there were 102,237 (SD: 52,725) visits with discharge amphetamine prescriptions per year. There was a strong, linear increase in number of visits that involved a discharge amphetamine salt prescription (PC = 0.92, p = 0.001). In 2012, there were a total of 23,676 visits and in 2019, a total of 124,773 visits (427% increase). There was no trend in visits where both an amphetamine and opioid were prescribed (PC: 0.61, p = 0.06).

CONCLUSION

There have been increases in discharge prescriptions for amphetamines in the ED over time. This was largely driven by prescriptions for amphetamine salts. Future research initiatives should continue to monitor this trend and in prescriptions and associated abuse in the setting of rising amphetamine abuse.

Links between excessive daytime sleepiness and EEG power and activation in two subtypes of ADHD

OBJECTIVES

This study aimed to replicate previously reported EEG characteristics between typically developing (TD) children and two subtypes of Attention Deficit Hyperactivity Disorder (ADHD) using a frontal, single-channel, dry-sensor portable EEG device, and explore whether differences are moderated by excessive daytime sleepiness (EDS).

METHODS

Children with ADHD Inattentive (ADHD-I) and ADHD Combined presentation (ADHD-C) and typically-developing (TD) children (N = 34 in each group) had frontal EEG recorded during eyes-closed resting, eyes-open resting, and focus tasks. Participants also completed the Children's Self-Report Sleep Patterns - Sleepiness Scale as a measure of EDS.

RESULTS

Consistent with previous literature, there were increases in frontal delta and theta power in the ADHD-C compared to ADHD-I and TD groups, in all conditions. Novel power and activation effects in ADHD subtypes, as well as significant group and EDS interactions for alpha and beta power were also found.

CONCLUSIONS

These findings highlight the importance of considering ADHD subtypes and EDS when exploring EEG characteristics, and have important implications for the diagnosis and treatment of children with ADHD.

Common practical questions - and answers - at the British Association for Psychopharmacology child and adolescent psychopharmacology course

The British Association for Psychopharmacology course on child and adolescent psychopharmacology has been run for more than 20 years and is currently a very popular course, attracting around 140 delegates/year from across the United Kingdom and abroad. As Faculty of recent sessions of the course, we have selected the most common questions we have been asked in recent years and provided evidence-based and/or expert-informed answers. We have included 27 questions and answers related to attention-deficit/hyperactivity disorder, anxiety and depressive disorders, autism spectrum disorder, bipolar disorder, eating disorders, epilepsy (in differential diagnosis or comorbid with mental health conditions), obsessive-compulsive disorder, personality disorders, psychotic spectrum disorders, and tics/Tourette syndrome in children and young people. We hope that this article will be helpful for prescribers in their daily clinical practice and we look forward to further, high-level evidence informing the answers to these and other questions in child and adolescent psychopharmacology.

Evidence-based prescribing of medications for ADHD: where are we in 2023?

INTRODUCTION

A large number of randomized controlled trials (RCTs) and observational studies on the pharmacotherapy of ADHD are available.

AREAS COVERED

Based on a search in PubMed and PsycInfo (up to 15 September 2022), this review addresses to which extent this body of research is currently able to inform routine prescribing practice, in terms of the choice of medication, titration strategy, augmentation treatments, and use of alternative, non-approved treatments.

EXPERT OPINION

A growing body of evidence is informing prescribers on some, but certainly not all, aspects related to the pharmacological treatment of ADHD in the daily clinical practice, with important weaknesses/gaps that need to be addressed. First, evidence synthesis of RCTs is not able to inform decision-making at the individual patient level. Second, the maximum safe and effective doses, possibly beyond those currently recommended, are not well understood. Third, evidence from RCTs on augmenting strategies is still limited. Fourth, no novel agents with the same or higher effect size of stimulants, in terms of efficacy, but with better tolerability and lower abuse potential, have been found. Implementation of precision psychiatry approaches and stratification of patients in future RCTs will be key to, respectively, individualize the treatment strategies and test etiopathophysiology-based agents.

Translational cognitive systems: focus on attention

Cognitive dysfunction, particularly attentional impairment, is a core feature of many psychiatric disorders, yet is inadequately addressed by current treatments. Development of targeted therapeutics for the remediation of attentional deficits requires knowledge of underlying neurocircuit, cellular, and molecular mechanisms that cannot be directly assayed in the clinic. This level of detail can only be acquired by testing animals in cross-species translatable attentional paradigms, in combination with preclinical neuroscience techniques. The 5-choice continuous performance test (5C-CPT) and rodent continuous performance test (rCPT) represent the current state of the art of preclinical assessment of the most commonly studied subtype of attention: sustained attention, or vigilance. These tasks present animals with continuous streams of target stimuli to which they must respond (attention), in addition to non-target stimuli from which they must withhold responses (behavioral inhibition). The 5C-CPT and rCPT utilize the same measures as gold-standard clinical continuous performance tests and predict clinical efficacy of known pro-attentional drugs. They also engage common brain regions across species, although efforts to definitively establish neurophysiological construct validity are ongoing. The validity of these tasks as translational vigilance assessments enables their use in characterizing the neuropathology underlying attentional deficits of animal models of psychiatric disease, and in determining therapeutic potential of drugs ahead of clinical testing. Here, we briefly review the development and validation of such tests of attentional functioning, as well as the data they have generated pertaining to inattention, disinhibition, and impulsivity in psychiatric disorders.

Biological Predictors of Treatment Response in Adult Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review

Background: Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent condition with onset in childhood and in many cases persisting into adulthood. Even though an increasing number of studies have investigated the efficacy of pharmacotherapy in the management of adult ADHD, few authors have tried to identify the biological predictors of treatment response. Objectives: To summarize the available data about the biological markers of treatment response in adults affected by ADHD. Methods: A search on the main biomedical and psychological archives (PubMed, Embase, Scopus, and PsycINFO) was performed. Manuscripts in English, published up to May 2022 and having the biological predictors of treatment response in adults with ADHD as their main topic, were included. Results: A total of 3855 articles was screened. Twenty-two articles were finally included. Most of the manuscripts studied neuroimaging and electrophysiological factors as potential predictors of treatment response in adult ADHD patients. No reliable markers were identified until now. Promising findings on this topic regard genetic polymorphisms in snap receptor (SNARE) proteins and default mode network-striatum connectivity. Conclusions: Even though some biological markers seem promising for the prediction of treatment response in adults affected by ADHD, further studies are needed to confirm the available data in the context of precision medicine.

Sleep-Related Breathing Disorders in Children—Red Flags in Pediatric Care

Objectives: In recent years, we have witnessed a growing interest in pediatric sleep-related breathing disorders (SRBD). Although a Pediatric Sleep Questionnaire (PSQ) exists and was found reliable in screening SRBD in children, many of the children remain underdiagnosed. The aim of the present study was to define anamnestic and clinical findings that can serve as red flags indicating the presence of SRBD in children. Methods: 227 children aged 4–12 years old were evaluated with regard to the following parameters: (i) anamnestic variables (e.g., general state of health, oral habits, bruxism, esophageal reflux, sleep continuity, snoring); (ii) clinical parameters (e.g., oral mucosa, palate, tonsils, tongue, floor of the mouth, angle classification, gingival health, caries risk) and (iii) presence of SRBD (through the PSQ). Results: Significant differences between children with and without SRBD were observed regarding continuous sleep, developmental delay, mouth breathing, and snoring. Taking medications for ADHD increased the odds of SRBD in children by over seven times, non-continuous sleep increased the odds of SRBD by six times, mouth breathing increased the odds by almost five times, and snoring increased the odds by over three times. Conclusions: Child caregivers from various fields (dentists, orthodontists, pediatric physicians, school nurses) should actively inquire about disturbed sleep, medications for ADHD, snoring, and mouth breathing among their young patients. Initial screening through a few simple questions may help raise red flags that can assist in the early detection of SRBD in children and lead to proper diagnosis and treatment.

Attention-deficit/hyperactive disorder updates

Background

Attention-deficit/hyperactive disorder (ADHD) is a neurodevelopmental disorder that commonly occurs in children with a prevalence ranging from 3.4 to 7.2%. It profoundly affects academic achievement, well-being, and social interactions. As a result, this disorder is of high cost to both individuals and society. Despite the availability of knowledge regarding the mechanisms of ADHD, the pathogenesis is not clear, hence, the existence of many challenges especially in making correct early diagnosis and provision of accurate management.

Objectives

We aimed to review the pathogenic pathways of ADHD in children. The major focus was to provide an update on the reported etiologies in humans, animal models, modulators, therapies, mechanisms, epigenetic changes, and the interaction between genetic and environmental factors.

Methods

References for this review were identified through a systematic search in PubMed by using special keywords for all years until January 2022.

Results

Several genes have been reported to associate with ADHD: DRD1, DRD2, DRD4, DAT1, TPH2, HTR1A, HTR1B, SLC6A4, HTR2A, DBH, NET1, ADRA2A, ADRA2C, CHRNA4, CHRNA7, GAD1, GRM1, GRM5, GRM7, GRM8, TARBP1, ADGRL3, FGF1, MAOA, BDNF, SNAP25, STX1A, ATXN7, and SORCS2. Some of these genes have evidence both from human beings and animal models, while others have evidence in either humans or animal models only. Notably, most of these animal models are knockout and do not generate the genetic alteration of the patients. Besides, some of the gene polymorphisms reported differ according to the ethnic groups. The majority of the available animal models are related to the dopaminergic pathway. Epigenetic changes including SUMOylation, methylation, and acetylation have been reported in genes related to the dopaminergic pathway.

Conclusion

The dopaminergic pathway remains to be crucial in the pathogenesis of ADHD. It can be affected by environmental factors and other pathways. Nevertheless, it is still unclear how environmental factors relate to all neurotransmitter pathways; thus, more studies are needed. Although several genes have been related to ADHD, there are few animal model studies on the majority of the genes, and they do not generate the genetic alteration of the patients. More animal models and epigenetic studies are required.

Toward Precision Medicine in ADHD

Attention-Deficit Hyperactivity Disorder (ADHD) is a complex and heterogeneous neurodevelopmental condition for which curative treatments are lacking. Whilst pharmacological treatments are generally effective and safe, there is considerable inter-individual variability among patients regarding treatment response, required dose, and tolerability. Many of the non-pharmacological treatments, which are preferred to drug-treatment by some patients, either lack efficacy for core symptoms or are associated with small effect sizes. No evidence-based decision tools are currently available to allocate pharmacological or psychosocial treatments based on the patient's clinical, environmental, cognitive, genetic, or biological characteristics. We systematically reviewed potential biomarkers that may help in diagnosing ADHD and/or stratifying ADHD into more homogeneous subgroups and/or predict clinical course, treatment response, and long-term outcome across the lifespan. Most work involved exploratory studies with cognitive, actigraphic and EEG diagnostic markers to predict ADHD, along with relatively few studies exploring markers to subtype ADHD and predict response to treatment. There is a critical need for multisite prospective carefully designed experimentally controlled or observational studies to identify biomarkers that index inter-individual variability and/or predict treatment response.

Evaluating the pharmacokinetics of extended release viloxazine in the treatment of children with attention-deficit/hyperactivity disorder

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood and impacts function negatively in multiple settings. Current treatments include stimulants, which inhibit the reuptake of dopamine and norepinephrine, a nonstimulant norepinephrine reuptake inhibitor (NRI) atomoxetine, and alpha-2 agonists clonidine extended release (ER) and guanfacine ER. Despite the effectiveness of these medications some patients do not respond to available drugs or may experience tolerability issues that hinder their use.

AREAS COVERED

Viloxazine, a serotonin norepinephrine modulating agent, was used outside of the United States (U.S.) as an effective antidepressant for several decades, but its use fell out of favor due to the need for multiple daily dosing. An ER viloxazine formulation was recently approved by the U. S. Food and Drug Administration (FDA) for the treatment of ADHD. The efficacy, pharmacokinetics and metabolism of viloxazine and viloxazine ER are reviewed.

EXPERT OPINION

Viloxazine ER is the first nonstimulant approved to treat ADHD in more than a decade. Although they have not been directly compared, the effect size of viloxazine ER is less than has been observed for stimulants. However, its pharmacokinetic properties and tolerability make viloxazine ER a useful addition to the collection of FDA approved ADHD treatments.

Trace amine-associated receptor 1 modulates motor hyperactivity, cognition, and anxiety-like behavior in an animal model of ADHD

Trace amine-associated receptor 1 (TAAR1) is a G protein-coupled receptor that has recently been implicated in several psychiatric conditions related to monoaminergic dysfunction, such as schizophrenia, substance use disorders, and mood disorders. Although attention-deficit/hyperactivity disorder (ADHD) is also related to changes in monoaminergic neurotransmission, studies that assess whether TAAR1 participates in the neurobiology of ADHD are lacking. We hypothesized that TAAR1 plays an important role in ADHD and might represent a potential therapeutic target. Here, we investigate if TAAR1 modulates behavioral phenotypes in Spontaneously Hypertensive Rats (SHR), the most validated animal model of ADHD, and Wistar Kyoto rats (WKY, used as a control strain). Our results showed that TAAR1 is downregulated in ADHD-related brain regions in SHR compared with WKY. While intracerebroventricular (i.c.v.) administration of the selective TAAR1 antagonist EPPTB impaired cognitive performance in SHR, i.c.v. administration of highly selective TAAR1 full agonist RO5256390 decreased motor hyperactivity, novelty-induced locomotion, and induced an anxiolytic-like behavior. Overall, our findings show that changes in TAAR1 levels/activity underlie behavior in SHR, suggesting that TAAR1 plays a role in the neurobiology of ADHD. Although additional confirmatory studies are required, TAAR1 might be a potential pharmacological target for individuals with this disorder.

Multimodal treatment efficacy differs in dependence of core symptom profiles in adult Attention-Deficit/Hyperactivity Disorder: An analysis of the randomized controlled COMPAS trial

There is broad consensus that to improve the treatment of adult Attention-Deficit/Hyperactivity Disorder (ADHD), the various therapy options need to be tailored more precisely to the individual patient's needs and specific symptoms. This post-hoc analysis evaluates the multimodal effects of first-line medication (methylphenidate [MPH] vs placebo [PLB]) and psychotherapeutic (group psychotherapy [GPT] vs clinical management [CM]) treatments on the ADHD core symptoms inattention, hyperactivity and impulsivity. For the two-by-two factorial, observer-blinded, multicenter, randomized controlled Comparison of Methylphenidate and Psychotherapy in Adult ADHD Study (COMPAS; ISRCTN54096201), 419 outpatients with ADHD were considered for analysis. ADHD symptoms were assessed by blind observer-rated and patient-rated Conners Adult ADHD Rating Scales before treatment (T1), 13 weeks (T2) and 26 weeks (T3) after T1, at treatment completion after 52 weeks (T4), and at follow-up (130 weeks, T5). MPH was superior to PLB in improving symptoms of inattention at almost all endpoints (observer-rated T2, T3, T4, T5; patient-rated T2, T3, T4), while a significant decrease in hyperactivity and impulsivity was at first found after 6 months of treatment. CM compared to GPT decreased inattention and impulsivity in the early treatment phase only (observer-rated T2, patient-rated T2, T3). In conclusion, while MPH seems to have a direct and sustained effect on inattention, premature medication discontinuation should particularly be avoided in patients with hyperactive-impulsive symptoms. Also, especially in high inattention and/or impulsivity presentations, initial individual patient management might be beneficial. Consequently, considering individual core symptom profiles may enhance the efficacy of treatments in adult ADHD.

Stimulants

Stimulants have been available for the treatment of attention-deficit/hyperactivity disorder (ADHD) for more than 70 years and are the most effective medications available. During the past 2 decades, several new immediate-release (IR) and extended-release methylphenidate (MPH) and amphetamine (AMPH) formulations have become available. These products differ by dose form (capsules, tablets, oral suspensions, oral disintegrating tablets, and patch), by onset and duration of effect, and by bioavailability. The side effect profile is generally similar for all compounds. Although the products are similar, individual patients may have a better response or tolerability to a particular class (MPH or AMPH) or formulation.

The Pharmacokinetics and Pharmacogenomics of Psychostimulants

The psychostimulants-amphetamine and methylphenidate-have been in clinical use for well more than 60 years. In general, both stimulants are rapidly absorbed with relatively poor bioavailability and short half-lives. The pharmacokinetics of both stimulants are generally linear and dose proportional although substantial interindividual variability in pharmacokinetics is in evidence. Amphetamine (AMP) is highly metabolized by several oxidative enzymes forming multiple metabolites while methylphenidate (MPH) is primarily metabolized by hydrolysis to the inactive metabolite ritalinic acid. At present, pharmacogenomic testing as an aid to guide dosing and personalized treatment cannot be recommended for either agent. Few pharmacokinetically based drug-drug interactions (DDIs) have been documented for either stimulant.

Dorsal-to-ventral imbalance in the superior longitudinal fasciculus mediates methylphenidate's effect on beta oscillations in ADHD

While pharmacological treatment with methylphenidate (MPH) is a first line intervention for ADHD, its mechanisms of action have yet to be elucidated. We here seek to identify the white matter tracts that mediate MPH's effect on beta oscillations. We implemented a double-blind placebo-controlled crossover design, where boys diagnosed with ADHD underwent behavioral and MEG measurements during a spatial attention task while on and off MPH. The results were compared with an age/IQ-matched control group. Estimates of white matter tracts were obtained using diffusion tensor imaging (DTI). Via a stepwise model selection strategy, we identified the fiber tracts (regressors) significantly predicting values of the dependent variables of interest (i.e., oscillatory power, behavioral performance, and clinical symptoms): the anterior thalamic radiation (ATR), the superior longitudinal fasciculus ("parietal endings") (SLFp), and superior longitudinal fasciculus ("temporal endings") (SLFt). ADHD symptoms severity was associated with lower fractional anisotropy (FA) within the ATR. In addition, individuals with relatively higher FA in SLFp compared to SLFt, led to stronger behavioral effects of MPH in the form of faster and more accurate responses. Furthermore, the same parietotemporal FA gradient explained the effects of MPH on beta modulation: subjects with ADHD exhibiting higher FA in SLFp compared to SLFt also displayed greater effects of MPH on beta power during response preparation. Our data suggest that the behavioral deficits and aberrant oscillatory modulations observed in ADHD depend on a possibly detrimental structural connectivity imbalance within the SLF, caused by a diffusivity gradient in favor of parietal rather than temporal, fiber tracts.

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.

Current Pharmacological Treatments for ADHD

Attention-Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental condition associated with impaired function and increased risk of poor outcomes in children, young people and adults with the condition. Currently approved pharmacological treatments for ADHD include a range of stimulant (methylphenidate, amphetamine) and nonstimulant (atomoxetine, guanfacine, clonidine) medications. All have been shown to be effective in treating the symptoms of ADHD and improving other functional outcomes including quality of life, academic performance, rates of accidents and injuries, and do not appear to be associated with significant adverse outcomes or side effects. In this chapter, we review medications for ADHD by summarising the mechanisms of action of each of the two main classes of compounds (stimulants and nonstimulants), the formulations of the most commonly prescribed medications within each class, their efficacy in treating ADHD symptoms and other outcomes, and other factors that influence treatment decisions including side effects and tolerability, comorbidities and medical history. We conclude with a summary of the treatment decisions made by clinicians and suggest some next steps for research. Further research is needed to understand the mechanisms of action of these medications and how exactly they improve symptoms, and to examine their effects on commonly occurring comorbidities.

New Drugs to Treat ADHD: Opportunities and Challenges in Research and Development

Since the landmark MTA (Multimodal Treatment of ADHD) trial unequivocally demonstrated the efficacy of methylphenidate, catecholaminergic drugs, especially stimulants, have been the therapeutic mainstay in treatment of Attention-Deficit Hyperactivity Disorder (ADHD). We review the new drugs which have entered the ADHD formulary. The lessons learned from drug-candidates that have succeeded in clinical trials together with those that have not have also been considered. What emerges confirms and consolidates the hypothesis that clinically effective ADHD drugs indirectly or directly increase catecholaminergic neurotransmission in the prefrontal cortex (PFC). Attempts to enhance catecholaminergic signalling through modulatory neurotransmitter systems or cognitive-enhancing drugs have all failed. New drugs approved for ADHD are catecholaminergic reuptake inhibitors and releasing agents, or selective noradrenaline reuptake inhibitors. Triple reuptake inhibitors with preferential effects on dopamine have not been successful. The substantial number of failures probably accounts for a continued focus on developing novel catecholaminergic and noradrenergic drugs, and a dearth of drug-candidates with novel mechanisms entering clinical development. However, substantial improvements in ADHD pharmacotherapy have been achieved by the almost exclusive use of once-daily medications and prodrugs, e.g. lisdexamfetamine and Azstarys^®, which improve compliance, deliver greater efficacy and reduce risks for diversion and abuse.

A Practical, Evidence-informed Approach to Managing Stimulant-Refractory Attention Deficit Hyperactivity Disorder (ADHD)

Stimulants (methylphenidate or amphetamines) are the recommended first-line option for the pharmacological treatment of individuals with attention deficit hyperactivity disorder (ADHD). However, some patients with ADHD will not respond optimally to stimulants. Here, we discuss strategies to manage stimulant-refractory ADHD, based on the recommendations advanced in clinical guidelines, knowledge of expert practice in the field, and our own clinical recommendations, informed by a comprehensive literature search in PubMed, PsycInfo, EMBASE + EMBASE classic, OVID Medline, and Web of Science (up to 30 March 2021). We first highlight the importance of stimulant optimization as an effective strategy to increase response. We then discuss a series of factors that should be considered before using alternative pharmacological strategies for ADHD, including poor adherence, time action properties of stimulants (and wearing-off of effects), poor tolerability (that prevents the use of higher, more effective doses), excessive focus on or confounding from presence of comorbid non-ADHD symptoms, and tolerance. Finally, we consider the role of non-stimulants and combined pharmacological approaches. While the choice of medication for ADHD is still to a large extent based on a trial-and-error process, there are reasonably accepted data and guidelines to aid in clinical decision-making. It is hoped that advances in precision psychiatry in the years ahead will further guide prescribers to tailor medication choice to the specific characteristics of the patient.

Methylphenidate for attention-deficit/hyperactivity disorder in adults: a narrative review

RATIONALE

Psychostimulants, including methylphenidate (MPH), are the mainstay of pharmacotherapy for attention-deficit/hyperactivity disorder (ADHD) in adults. Even though MPH is the most commonly used medication for ADHD these days, there are relatively few resources available that provide comprehensive insight into the pharmacological and clinical features of the compound.

OBJECTIVE

The aim of this paper is to provide an up-to-date outline of the pharmacology and clinical utility of MPH for ADHD in adult patients.

METHODS

While conducting the narrative review, we applied structured search strategies covering the two major online databases (MEDLINE and Cochrane Central Register of Controlled Trials). In addition, we performed handsearching of reference lists of relevant papers.

RESULTS

Methylphenidate exhibits multimodal mechanism of action, working primarily as a dopamine and noradrenaline reuptake inhibitor. It also protects the dopaminergic system against the ongoing 'wearing off' (by securing a substantial reserve pool of the neurotransmitter, stored in the presynaptic vesicles). In placebo-controlled trials, MPH was shown to be moderately effective both against the core ADHD symptoms (standardized mean difference [SMD], 0.49; 95% confidence interval [CI], 0.35-0.64), and the accompanying emotion regulation deficits (SMD, 0.34; 95% CI, 0.23-0.45). The most common adverse events related to long-term treatment with MPH are decreased appetite (~ 20%), dry mouth (15%), heart palpitations (13%), gastrointestinal infections (~ 10%), and agitation/feeling restless (~ 10%).

CONCLUSIONS

There is substantial body of evidence to suggest that MPH is an effective and safe treatment option for adults with ADHD.

Effects of methylphenidate on height, weight and blood biochemistry parameters in prepubertal boys with attention deficit hyperactivity disorder: an open label prospective study

Background: Adverse effects of stimulants on growth in children have long been studied, but the results remain to be clarified, because metabolic changes or predictors accompanying the growth deviations were not sufficiently studied. Objective: This open label-prospective study investigated the effects of methylphenidate (MPH) on weight, height, blood biochemistry in children with attention deficit hyperactivity disorder (ADHD). Method: Prepubertal boys treated with MPH in Child and Adolescent Psychiatry Clinic at Antalya Training and Research Hospital in Health Sciences University, Turkey were recruited. Height and weight z-scores and fasting blood samples were taken at baseline and 6^th month. Changes were compared by paired-samples t-test or Wilcoxon signed-rank test. Any association between the changes in growth and biochemical values was analyzed by Spearman's Rank-Order Correlation. The statistical significance threshold was p<0.01. Results: 31 boys aged 74 to 104 months were enrolled in the study sample (mean=87.6, Standard Deviation (SD)=9.2). Osmotic release oral system-MPH (18 mg/day) was used in 77.4% (N=24) and immediate release-MPH (5 mg three times a day) in 22.5% (N=7). Average daily drug dose was 0.66 mg/kg (SD=0.12). Baseline weight z-score was 0.63 (SD=1.12), decreased significantly at 6 months (0.24 [SD=1.04]) (Z=-4.44, p=0.000, r=0.5) (median z-score was 0.53 at baseline, -0.11 at 6 months). Baseline height z-score (0.23[SD=0.87]) was not suppressed significantly at 6 months (0.28[SD=0.85])(t(30) = ‒1.50, p=0.14). Glucose (t(30) = -4.33, p=0.000, r=0.6), creatinine (t(30)=-3.28, p=0.003, r=0.5) and 25OH-VitD (N=29, Z=-3.98, p=0.000, r=0.5) increased but alkaline phosphatase (ALP) decreased (t(28)=3.63, p=0.001, r=0.5). The differences in W-SDS and ALP were positively correlated (r=0.47, p=0.009). Conclusions: Our results indicate the importance of monitoring blood variables that may accompany growth changes early in MPH treatment and should be further assessed in larger samples.

Evidence-based pharmacological treatment options for ADHD in children and adolescents

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity, causing functional impairment. Its prevalence lies at approximately 5% in children and adolescents and at approximately 2.5% in adults. The disorder follows a multifactorial etiology and shows a high heritability. Patients show a high interindividual and intraindividual variability of symptoms, with executive deficits in several cognitive domains. Overall, ADHD is associated with high rates of psychiatric comorbidities, and insufficient treatment is linked to adverse long-term outcomes. Current clinical guidelines recommend an individualized multimodal treatment approach including psychoeducation, pharmacological interventions, and non-pharmacological interventions. Available medications include stimulants (methylphenidate, amphetamines) and non-stimulants (atomoxetine, guanfacine, clonidine). While available pharmacological treatment options for ADHD show relatively large effect sizes (in short-term trials) and overall good tolerability, there is still a need for improvement of current pharmacotherapeutic strategies and for the development of novel medications. This review summarizes available pharmacological treatment options for ADHD in children and adolescents, identifies current issues in research and evidence gaps, and provides an overview of ongoing efforts to develop new medications for the treatment of ADHD in children and adolescents by means of a systematic cross-sectional analysis of the clinical trials registry www.clinicaltrials.gov.

Lifetime evolution of ADHD treatment

Attention-deficit hyperactivity disorder (ADHD), has been traditionally considered a neurodevelopmental disorder affecting children and adolescents characterized by inattention, hyperactivity, disruptive behavior, and impulsivity. Although still debated, it is evident that ADHD is also present in adulthood, but this diagnosis is rarely carried out, mainly for the frequent comorbidity with other psychiatric and/or substance abuse disorders. Given the need to shed more light on the pharmacological treatment of ADHD, we performed a naturalistic review to review and comment on the available literature of ADHD treatment across the lifespan. Indeed, stimulants are endowed of a prompt efficacy and safety, whilst non-stimulants, although requiring some weeks to be fully effective, are useful when a substance abuse history is detected. In any case, the pharmacological management of ADHD appears to be still largely influenced by the individual experience of the clinicians. Further longitudinal studies with a careful and detailed characterization of participants across different phases of the lifespan are also required to provide relevant confirmations (or denials) regarding pharmacological treatments amongst the different age groups.

Effectiveness and safety of dexamphetamine sulfate (Attentin®) in the routine treatment of children and adolescents with ADHD: results from a 12-month non-interventional study

Background

Randomized controlled trials have shown that dexamphetamine sulfate (DEX) is efficacious in the treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents; however, data on the effectiveness and safety of DEX in routine practice are scarce.

Objective

This study investigated the long-term effectiveness and safety of Attentin^® (immediate-release DEX) in children and adolescents with ADHD in routine practice.

Methods

ATTENTION was a multicenter, prospective, observational, non-interventional study that enrolled pediatric patients with ADHD (aged 6-17 years) with a clinically inadequate response to previous methylphenidate (MPH) treatment. Patients were assessed at baseline and two follow-up visits after approx. 6 and 12 months of DEX treatment. The primary endpoint was the investigator-rated ADHD rating scale IV (ADHD-RS-IV) total score change from baseline to the first follow-up visit.

Results

The study enrolled 140 patients (mean age: 11.2 years). Significant reductions in ADHD-RS-IV total scores were observed in the titration phase and were maintained up to the second follow-up visit. The mean ADHD-RS-IV total score change from baseline to the first follow-up visit was -11.9 (27.1 vs. 13.4, p < .001). Beneficial effects of DEX were observed on both ADHD-RS-IV subscales ('hyperactivity/impulsivity' and 'inattention') and in both children and adolescents. Clinical response, defined as a reduction in the ADHD-RS-IV total score of at least 30% at the first follow-up visit, was observed in 78.1% of patients. Patients reported an average onset of action of 36.2 minutes and an average duration of action of 6.5 hours after intake of the first dose of DEX in the morning. DEX was well tolerated. Small significant increases in mean systolic and diastolic blood pressure compared to baseline were observed.

Conclusions

Attentin^® is an effective and well-tolerated long-term treatment for pediatric ADHD patients with a clinically inadequate response to previous MPH treatment.

Evaluation of the abuse potential of pitolisant, a selective H3-receptor antagonist/inverse agonist, for the treatment of adult patients with narcolepsy with or without cataplexy

Objectives

To evaluate the human abuse potential of pitolisant, a selective histamine 3 (H₃)-receptor antagonist/inverse agonist recently approved by the US Food and Drug Administration for the treatment of excessive daytime sleepiness in adult patients with narcolepsy.

Methods

Nondependent, recreational stimulant users able to distinguish phentermine HCl 60 mg from placebo in a drug discrimination test were randomized in a four-period, double-blind, crossover design to receive single doses of pitolisant 35.6 mg (therapeutic dose), pitolisant 213.6 mg (supratherapeutic dose), phentermine HCl 60 mg, and placebo. The primary endpoint was maximum effect (E_max) on the 100-point Drug Liking (“at this moment”) visual analog scale.

Results

In 38 study completers (73.7% male; 65.8% white; mean age, 33.3 years), mean Drug Liking E_max was significantly greater for phentermine versus pitolisant 35.6 mg (mean difference, 21.4; p < 0.0001) and pitolisant 213.6 mg (mean difference, 19.7; p < 0.0001). Drug Liking E_max was similar for pitolisant (both doses) and placebo. Similarly, for key secondary measures of Overall Drug Liking and willingness to Take Drug Again, mean E_max scores were significantly greater for phentermine versus pitolisant (both doses) and similar for pitolisant (both doses) versus placebo. The incidence of adverse events was 82.1% after phentermine HCl 60 mg, 72.5% after pitolisant 213.6 mg, 47.5% after pitolisant 35.6 mg, and 48.8% after placebo administration.

Conclusions

In this study, pitolisant demonstrated significantly lower potential for abuse compared with phentermine and an overall profile similar to placebo; this suggests a low risk of abuse for pitolisant.

Clinical Trial Registration

ClinicalTrials.gov NCT03152123. Determination of the abuse potential of pitolisant in healthy, nondependent recreational stimulant users. https://clinicaltrials.gov/ct2/show/NCT03152123.

Novel Formulations of ADHD Medications: Stimulant Selection and Management

Attention-deficit hyperactivity disorder (ADHD) is the most commonly diagnosed psychiatric disorder in children and adolescents in the United States. In 2016, approximately 3.8 million U.S. children ages 2 to 17 years with ADHD were being treated with medication. There are approximately 30 different amphetamine (AMPH) and methylphenidate (MPH) formulations on the market. These include immediate-release and extended-release compounds. The extended-release formulations contain various ratios of immediate-release and extended-release components, which determine the pharmacokinetic (PK) profile. For stimulants, the PK and pharmacodynamic (PD) profiles are tightly linked, and the immediate-release and extended-release percentages influence onset and duration of drug effects. Choosing the right stimulant medication for a patient depends on an understanding of the PK/PD profile, the time of day that symptoms are most impairing, the need for morning and evening symptom control and individual patient preferences.

Sleep Variables as Predictors of Treatment Effectiveness and Side Effects of Stimulant Medication in Newly Diagnosed Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

There is a growing body of research on the impact of stimulant medication on sleep in children with attention-deficit/hyperactivity disorder (ADHD). Negative sleep side effects are a common reason for nonadherence or for discontinuing a course of treatment. However, there is no published evidence as to whether pretreatment sleep can predict responses to treatment and the emergence of side effects.

METHOD

In this study, baseline sleep variables were used to predict therapeutic effect (i.e., reduction of ADHD symptoms) and side effects (both sleep and global side effects) in a sample of newly diagnosed, medication-naive children (n = 50).

RESULTS

The results of hierarchical regression analysis showed that parent-reported shorter sleep duration before medication treatment significantly predicted better response to treatment, independent of pretreatment ADHD symptoms. Baseline sleep features did not significantly predict global (nonsleep) side effects but did predict increased sleep side effects during treatment.

CONCLUSION

These results indicate that baseline sleep variables may be helpful in predicting therapeutic response to medication and sleep disturbance as a side effect of stimulant medication.

Reviewing the role of emerging therapies in the ADHD armamentarium

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder that can be treated with both pharmacologic and nonpharmacologic modalities. Effective drug treatments for ADHD have been available for more than six decades. However, initial treatments had limitations in duration of effect, need for multiple daily doses, requirement for patients to swallow intact tablets, adverse effects and risk for abuse and diversion. During the past 20 years, more than two dozen stimulant and nonstimulant drugs have been developed. Nonetheless, there remain unmet needs in the treatment of ADHD.Areas covered: New stimulant and nonstimulant formulations in development are reviewed with emphasis on drugs in phase II and III trials. Efficacy, mechanism of action and adverse effect data are described where available. Abuse liability studies are described for abuse-deterrent formulations in development.Expert opinion: The review found a robust pipeline of stimulants and nonstimulants. Medications in development are formulated to optimize onset and duration of effect, alter the time of administration, obviate the need to swallow whole capsules or tablets and to deter abuse. While each of these formulations may fill a unique niche, these incremental improvements based on new drug delivery technologies may lead to very significant clinical effects.

Amphetamine Use in the Elderly: A Systematic Review of the Literature

Objective:

To systematically review the literature on the therapeutic use of amphetamine, lisdexamfetamine and methylphenidate in elderly population with and without dementia.

Methods:

We conducted two researches on the PubMed, Scopus and Embase using the keywords (“elderly”) AND (“amphetamine” OR “methylphenidate” OR “lisdexamfetamine”) and then (“Alzheimer” OR “dementia”) AND (“amphetamine” OR “methylphenidate” OR “lisdexamfetamine”).

Results:

Twenty-nine papers met all the eligibility criteria. The results are encouraging as 81.5% of the studies showed clinical improvement of the investigated condition.

Conclusion:

Amphetamines and methylphenidate are probably effective strategies for different conditions in the elderly population. However, further studies are needed to provide more robust evidence on efficacy, dosage and safety for this population.

Attention Networks in ADHD Adults after Working Memory Training with a Dual n-Back Task

Patients affected by Attention-Deficit/Hyperactivity Disorder (ADHD) are characterized by impaired executive functioning and/or attention deficits. Our study aim is to determine whether the outcomes measured by the Attention Network Task (ANT), i.e., the reaction times (RTs) to specific target and cue conditions and alerting, orienting, and conflict (or executive control) effects are affected by cognitive training with a Dual n-back task. We considered three groups of young adult participants: ADHD patients without medication (ADHD), ADHD with medication (MADHD), and age/education-matched controls. Working memory training consisted of a daily practice of 20 blocks of Dual n-back task (approximately 30 min per day) for 20 days within one month. Participants of each group were randomly assigned into two subgroups, the first one with an adaptive mode of difficulty (adaptive training), while the second was blocked at the level 1 during the whole training phase (1-back task, baseline training). Alerting and orienting effects were not modified by working memory training. The dimensional analysis showed that after baseline training, the lesser the severity of the hyperactive-impulsive symptoms, the larger the improvement of reaction times on trials with high executive control/conflict demand (i.e., what is called Conflict Effect), irrespective of the participants’ group. In the categorical analysis, we observed the improvement in such Conflict Effect after the adaptive training in adult ADHD patients irrespective of their medication, but not in controls. The ex-Gaussian analysis of RT and RT variability showed that the improvement in the Conflict Effect correlated with a decrease in the proportion of extreme slow responses. The Dual n-back task in the adaptive mode offers as a promising candidate for a cognitive remediation of adult ADHD patients without pharmaceutical medication.

The female side of pharmacotherapy for ADHD-A systematic literature review

OBJECTIVE

This comprehensive review examined sex differences in prescription rates and efficacy or effectiveness of pharmacotherapy treatment in girls and women with attention deficit hyperactivity disorder (ADHD), while identifying gaps in the scientific knowledge on this topic.

METHOD

A rigorous electronic database search was carried out in order to identify all published studies on female-specific effects of stimulants and non-stimulants in the treatment of ADHD. In total, 2672 studies were screened of which 21 studies (seven on prescription rates, 14 on effects of pharmacotherapy) met the inclusion criteria and were included for analysis.

RESULTS

In all seven studies on ADHD prescription rates, girls received significantly less prescriptions than boys, a difference however no longer seen in adults with the exception of one study. Each of the 14 studies on effectiveness / efficacy found at least one sex-difference in the effects of ADHD pharmacotherapy.

CONCLUSION

Several sex-differences are demonstrated in the prescription, usage and efficacy /effectiveness of both stimulant and non-stimulant ADHD pharmacotherapy. A single daily use of MPH may possibly not be optimal for girls with ADHD and ATX may be a promising medication for girls and women with ADHD. The robustness of this result requires further investigation.

Methylphenidate challenge test in adults with attention deficit/hyperactivity disorder (ADHD): Clinical effects and their predictors

OBJECTIVE

Adult and children attention deficit/hyperactivity disorder (ADHD) share similar symptoms and responses to drugs such as methylphenidate (MPH). Yet, in Europe, these drugs remain unlicensed for adults. We aimed to assess the effects of an acute MPH challenge on the four dimensions concentration, impulsivity, tension, and general well-being in ADHD adults, and identify predictors of improvement.

METHODS

Therapeutic Drug Monitoring was performed to measure MPH plasma levels. A Visual Analogue Scale was administered to patients before and after the acute MPH challenge to measure self-reported changes in the four dimensions.

RESULTS

After the acute MPH challenge, our 71 patients showed significant improvement in concentration and tension. The MPH challenge dose correlated with lower patients' age, greater side effects, increased concentration (p = .008) and decreased tension (p = .001). At multiple linear regression MPH plasma levels and absence of postdose side effects predicted concentration improvement, MPH plasma levels predicted tension improvement. MPH plasma levels were significantly higher in patients who reported an improvement in concentration, tension, and impulsivity compared to nonimprovers (p's from .001 to .004).

CONCLUSIONS

These findings point to the efficacy of MPH challenge in improving concentration and tension in adult ADHD, thus emphasizing the need for a broader treatment access for these patients.

Patterns of long-term ADHD medication use in Australian children

OBJECTIVE

Adherence to attention-deficit/hyperactivity disorder (ADHD) medication treatment is often suboptimal. This can compromise patient outcomes. We aimed to describe the patterns of ADHD medication use in Australian children, and characteristics associated with patterns of use.

DESIGN

Dispensing data were analysed for all redeemed prescriptions of methylphenidate, dexamphetamine and atomoxetine between May 2002 and March 2015 from waves 1 to 6 of the Longitudinal Study of Australian Children (n=4634, age 4-5 years at wave 1). Medication coverage was defined as the proportion of time between the first and the last redeemed prescriptions in which the child was taking medication. Associations between predictor variables (child sex, ADHD symptom severity, age at first prescription, family socioeconomic status (SES), single parent status, parent education and parent mental health) and medication coverage were examined using regression analyses.

RESULTS

166 (3.6%) children had ever redeemed a prescription for an ADHD medication. Boys had higher odds of having taken ADHD medication than girls (OR=3.9; 95% CI 2.7 to 5.7). The mean medication coverage was 59.8%. Medication coverage was lower in children from families of lower SES (β=4.0; 95% CI 0.2 to 7.8, p=0.04). Medication coverage was relatively high in the first year of prescription, then decreased progressively, only increasing again after 5 or 6 years of treatment.

CONCLUSIONS

Children with ADHD from socially disadvantaged families were less likely to receive medication consistently. Prescribers need to continue to support families over many years to ensure medication is used consistently for children with ADHD.

ADHD with Comorbid Bipolar Disorders: A Systematic Review of Neurobiological, Clinical and Pharmacological Aspects Across the Lifespan

BACKGROUND

Attention deficit hyperactivity (ADHD) disorder is a neurodevelopmental disorder characterized by inattention, hyperactivity, disruptive behaviour, and impulsivity. Despite considered typical of children for a long time, the persistence of ADHD symptoms in adulthood gained increasing interest during the last decades. Indeed, its diagnosis, albeit controversial, is rarely carried out even because ADHD is often comorbid with several other psychiatric diosrders, in particular with bipolar disorders (BDs), a condition that complicates the clinical picture, assessment and treatment.

AIMS

The aim of this paper was to systematically review the scientific literature on the neurobiological, clinical features and current pharmacological management of ADHD comorbid with BDs across the entire lifespan, with a major focus on the adulthood.

DISCUSSION

The pharmacology of ADHD-BD in adults is still empirical and influenced by the individual experience of the clinicians. Stimulants are endowed of a prompt efficacy and safety, whilst non-stimulants are useful when a substance abuse history is detected, although they require some weeks in order to be fully effective. In any case, an in-depth diagnostic and clinical evaluation of the single individual is mandatory.

CONCLUSION

The comorbidity of ADHD with BD is still a controversial matter, as it is the notion of adult ADHD as a distinct nosological category. Indeed, some findings highlighted the presence of common neurobiological mechanisms and overlapping clinical features, although disagreement does exist. In any case, while expecting to disentangle this crucial question, a correct management of this comorbidity is essential, which requires the co-administration of mood stabilizers. Further controlled clinical studies in large samples of adult ADHD-BD patients appear extremely urgent in order to better define possible therapeutic guidelines, as well as alternative approaches for this potentially invalidating condition.

Serum Levels of Vitamin A and Vitamin D and Their Association With Symptoms in Children With Attention Deficit Hyperactivity Disorder

Objective: To measure levels of vitamin A (VA) and vitamin D (VD) and the symptomatic association of their co-deficiencies on attention deficit hyperactivity disorder (ADHD) in Chinese children (6-9 years). Methods: Eighty-two children (69 boys and 13 girls; mean age = 7.1 ± 0.9 years at the time of the diagnosis) with ADHD were recruited as ADHD group. A total of 106 healthy children were recruited as the healthy control (HC) group. Serum levels of retinol and 25-hydroxyvitamin D (25(OH)D) of all children were evaluated using high-performance liquid chromatography (HPLC) and HPLC-tandem mass spectrometry. The Swanson, Nolan, and Pelham IV Rating Scale (SNAP-IV) was employed to assess the clinical symptoms of ADHD. Results: Children suffering from ADHD had significantly reduced serum levels of retinol and 25(OH)D compared with those of HCs, and the prevalence of VA deficiency and VD deficiency were higher in children suffering from ADHD. Serum concentrations of 25(OH)D and retinol were linked closely with the presence or absence of ADHD after adjustment for age, body mass index, season of blood sampling, and sun exposure. Serum concentrations of 25(OH)D and retinol showed a negative correlation with the total scores of SNAP-IV. Children with ADHD as well as VA and VD co-deficiency had increased SNAP-IV total scores and ADHD inattention subscale scores. Conclusion: VA deficiency and VD deficiency in children with ADHD were increased in comparison with that in HCs. VA and VD co-deficiency associated with ADHD symptom severity. Attention should be paid to regular testing of VA levels and VD levels. However, the mechanism of VA and VD in ADHD needs to be further studied. Interventional studies on VA and VD supplementation are recommended to further verify the relationship between VA and VD co-deficiency and ADHD.