Editorial: Attention-Deficit/Hyperactivity Disorder, Stimulant Medication, and Criminality: Commentary and Caution

Pioneering longitudinal studies of boys with hyperactivity by Satterfield et al.1 indicated that one of the most deleterious outcomes associated with attention-deficit/hyperactivity disorder (ADHD) is later antisocial behaviors. This risk grows when ADHD is accompanied by severe behavior problems.2 Though most children with ADHD will not go on to engage in criminal behavior, dimensional measures of externalizing behavior problems as well as categorical diagnoses of oppositional defiant disorder and conduct disorder have strong associations with ADHD. Moreover, cross-sectional studies of incarcerated adults indicate that 20% to 30% meet diagnostic criteria for ADHD.3 These associations between childhood ADHD, oppositional defiant disorder, and conduct disorder and later criminal behavior beg the question of whether treatment of ADHD can reduce the severity of, or in some cases prevent, criminal behavior.

Effects of Stimulant Treatment on Changes in Brain Activation During Reward Notifications in Drug Naïve Youth With ADHD

BACKGROUND

Research examining the potential effects of stimulant exposure in childhood on subsequent development of substance use disorder (SUD) have focused on differences in the brain reward system as a function of risk.

METHODS

18 drug naïve children ages 7 to 12 years (11 High Risk [ADHD + ODD/CD]; 7 Low Risk [ADHD only]), underwent fMRI scans before and after treatment with mixed amphetamine salts, extended release (MAS-XR). We examined correlations between clinical ratings and fMRI activation at baseline and following treatment as a function of risk status.

RESULTS

High Risk children had higher activation than Low Risk children at baseline during both the Reward and Surprising Non-Reward conditions. Treatment produced strong differential effects on brain activation pertinent to group and reward outcome.

CONCLUSIONS

Findings support the hypothesized role of reward mechanisms in SUD risk, and suggest that stimulant treatment may have differential effects on reward processing in relation to SUD risk.

In Memoriam: Professor Joseph Biederman's Contributions to Child and Adolescent Psychiatry

OBJECTIVE

To provide an overview of Joe Biederman's contributions to child and adolescent psychiatry.

METHOD

Nine colleagues described his contributions to: psychopharmacology, comorbidity and genetics, pediatric bipolar disorder, autism spectrum disorders, Tourette's and tic disorders, clinical and neuro biomarkers for pediatric mood disorders, executive functioning, and adult ADHD.

RESULTS

Joe Biederman left us with many concrete indicators of his contributions to child and adolescent psychiatry. He set up the world's first pediatric psychopharmacology clinic and clinical research program in child adolescent psychiatry. As a young faculty member he began a research program that led to many awards and eventual promotion to full professor at Harvard Medical School. He was for many years the most highly cited researcher in ADHD. He achieved this while maintaining a full clinical load and was widely respected for his clinical acumen.

CONCLUSION

The world is a better place because Joe Biederman was here.

Sleep Disordered Breathing and Risk for ADHD: Review of Supportive Evidence and Proposed Underlying Mechanisms

BACKGROUND

Accumulating evidence suggests that sleep disordered breathing (SDB) is under-recognized in youth and adults with ADHD. SDB may contribute to exacerbating pre-existing ADHD symptoms and may play a role in the development of cognitive deficits that may mimic ADHD symptoms.

METHOD

We conducted a focused review of publications on cross-prevalence, overlapping clinical and neurobiological characteristics and possible mechanisms linking SDB and ADHD.

RESULTS

Exiting studies suggest that co-occurrence of SDB and ADHD is as high as 50%, with frequent overlap of clinical symptoms such as distractibility and inattention. Mechanisms linking these conditions may include hypoxia during sleep, sleep fragmentation and activation of inflammation, all of which may affect brain structure and physiology to produce disturbances in attention.

CONCLUSIONS

The relationship between SDB and ADHD symptoms appear well-supported and suggests that more research is needed to better optimize procedures for SDB assessment in youth being evaluated and/or treated for ADHD.

Increased Rate of Familial Mediterranean Fever in Children With ADHD: A Population-Based Case-Control Study

OBJECTIVE

There is growing evidence of involvement of inflammatory mechanisms in ADHD. Previous studies found significantly higher rates of ADHD among children with FMF. The present study examined the rate of exposure to FMF in children with a later (within a 5-year period) diagnosis of ADHD compared to non-ADHD children.

METHODS

A population-based case-control study of all children (<18 years) registered in Leumit Health Services during 01.01.2006 to 06.30.2021. All cases met ICD-9/10 criteria for ADHD. They were matched by age, sex, and socioeconomic status on a 1:2 rate to randomly selected non-ADHD controls.

RESULTS

Fifty-six (0.30%) children with ADHD (N = 18,756) were previously diagnosed with FMF compared to 65 of 37,512 controls (0.17%). A significant, independent association existed between a preceding FMF diagnosis and a later ADHD diagnosis [OR = 1.72 (95% CI 1.18-2.51); p = .003].

CONCLUSIONS

The mechanisms underlying the association w between FMF and later ADHD diagnosis merit further elucidation.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD; also known as hyperkinetic disorder) is a common neurodevelopmental condition that affects children and adults worldwide. ADHD has a predominantly genetic aetiology that involves common and rare genetic variants. Some environmental correlates of the disorder have been discovered but causation has been difficult to establish. The heterogeneity of the condition is evident in the diverse presentation of symptoms and levels of impairment, the numerous co-occurring mental and physical conditions, the various domains of neurocognitive impairment, and extensive minor structural and functional brain differences. The diagnosis of ADHD is reliable and valid when evaluated with standard diagnostic criteria. Curative treatments for ADHD do not exist but evidence-based treatments substantially reduce symptoms and/or functional impairment. Medications are effective for core symptoms and are usually well tolerated. Some non-pharmacological treatments are valuable, especially for improving adaptive functioning. Clinical and neurobiological research is ongoing and could lead to the creation of personalized diagnostic and therapeutic approaches for this disorder.

Neurobiological basis of reinforcement-based decision making in adults with ADHD treated with lisdexamfetamine dimesylate: Preliminary findings and implications for mechanisms influencing clinical improvement

BACKGROUND

ADHD is often described as a disorder of altered reward sensitivity, yet few studies have examined the extent to which: (i) treatments for ADHD impact reward-related mechanisms; and (ii) changes in the reward system are associated with clinical improvement. This study addresses these issues - examining the extent to which clinical improvement following lisdexamfetamine (LDX) treatment is associated with changes in brain reward system activation.

METHODS

Twenty adults (M = 11, 55%, F = 9, 45%), ages 19-52 (M = 33.9, SD = 10.0) with ADHD participated in a randomized cross-over study with lisdexamfetamine (LDX) and placebo (PB). Changes in brain activation were assessed during functional magnetic resonance (fMRI) scans: after receiving 3-5 weeks of treatment with LDX and 3-5 weeks of no drug/PB. fMRI contrasts were derived from the passive-avoidance (PA) learning task, which assessed reward-related learning using computational variables. We analyzed the following conditions: the Choice-Phase, modulated by the expected value (EV; i.e., object-choose and object-reject), and the Feedback-Phase, modulated by the prediction error (PE; i.e., reward and punish). Clinical symptom severity was assessed via interview with the ADHD-Rating Scale (ADHD-RS-IV). To address the primary objective, we performed group-level mass-univariate regression analyses between LDX and PB of percent change of the ADHD-RS total scores and the four contrast images under the Choice- and Feedback-conditions. Significance was set at a whole-brain voxel-wise threshold of p < 0.05 with family-wise error (FWE) correction and an extent (cluster) threshold of 50 contiguous voxels.

RESULTS

Improvement in ADHD symptoms with LDX was accompanied by significantly increased activation in a series of brain regions previously implicated in reinforcement processing in the choice and feedback conditions (e.g., left caudate and putamen, right orbitofrontal cortex, left middle frontal, superior frontal, and precentral gyri).

CONCLUSIONS

These findings, while preliminary, are the first to show that ADHD symptom improvement with stimulant treatment is associated with increased responsiveness of brain systems engaged in reward processing. Results support the hypothesis that LDX treatment may restore balance to dysfunction (e.g., hypoactivation) within the brain reward circuitry in adults with ADHD. Trial RegistrationClinicaltrials.gov Identifier: NCT01924429.

Response to uncertainty in developmental origins of health and disease research: commentary on Nomura et al. (2022)

We appreciate the comments of Gilman et al. (2023) on our paper and their acknowledgement of its importance in highlighting the significance of this area of research. Further, their acknowledgment that the primary results of our study are in a range that is similar to those from other published studies of children exposed to highly stressful environmental events emphasizes the validity of our findings and the important extension of our results to children experiencing these events in utero. They, however, raised concerns about some of the results regarding specific types of psychiatric disorders and sex-specific results related to the prenatal Superstorm Sandy hurricane exposure. We comment on the various issues related to the paper below but will not respond to comments regarding the press coverage of this article, which we think are beyond the scope of this commentary.

Interaction of genetic liability for attention deficit hyperactivity disorder (ADHD) and perinatal inflammation contributes to ADHD symptoms in children

Objective

Genetic and environmental factors contribute to the development of Attention Deficit/Hyperactivity Disorder (ADHD). Perinatal inflammation is one of the promising environmental risk factors for ADHD, but the relationship between the genetic risk for ADHD and perinatal inflammation requires further examination.

Methods

A possible gene-environmental interaction between perinatal inflammation and ADHD polygenic risk score (ADHD-PRS) on ADHD symptoms was investigated in children aged 8-9 from the Hamamatsu Birth Cohort for Mothers and Children (N = 531). Perinatal inflammation was evaluated by the level of concentration of three cytokines assayed in umbilical cord blood. The genetic risk for ADHD was assessed by calculating ADHD-PRS for each individual using a previously collected genome-wide association study of ADHD.

Results

Perinatal inflammation (β [SE], 0.263 [0.017]; P < 0.001), ADHD-PRS (β [SE], 0.116[0.042]; P = 0.006), and an interaction between the two (β [SE], 0.031[0.011]; P = 0.010) were associated with ADHD symptoms. The association between perinatal inflammation and ADHD symptoms measured by ADHD-PRS was evident only in the two higher genetic risk groups (β [SE], 0.623[0.122]; P < 0.001 for the medium-high risk group; β [SE], 0.664[0.152]; P < 0.001 for the high-risk group).

Conclusion

Inflammation in the perinatal period both directly elevated ADHD symptoms and magnified the impact of genetic vulnerability on ADHD risk particularly among children aged 8-9 with genetically higher risk for ADHD.

Common and distinct fronto-striatal volumetric changes in heroin and cocaine use disorders

Different drugs of abuse impact the morphology of fronto-striatal dopaminergic targets in both common and unique ways. While dorsal striatal volume tracks with addiction severity across drug classes, opiates impact ventromedial prefrontal cortex (vmPFC) and nucleus accumbens (NAcc) neuroplasticity in preclinical models, and psychostimulants alter inhibitory control, rooted in cortical regions such as the inferior frontal gyrus (IFG). We hypothesized parallel grey matter volume changes associated with human heroin or cocaine use disorder: lower grey matter volume of vmPFC/NAcc in heroin use disorder and IFG in cocaine use disorder, and putamen grey matter volume to be associated with addiction severity measures (including craving) across both. In this cross-sectional study, we quantified grey matter volume (P < 0.05-corrected) in age/sex/IQ-matched individuals with heroin use disorder (n = 32, seven females), cocaine use disorder (n = 32, six females) and healthy controls (n = 32, six females) and compared fronto-striatal volume between groups using voxel-wise general linear models and non-parametric permutation-based tests. Overall, individuals with heroin use disorder had smaller vmPFC and NAcc/putamen volumes than healthy controls. Bilateral lower IFG grey matter volume patterns were specifically evident in cocaine versus heroin use disorders. Correlations between addiction severity measures and putamen grey matter volume did not reach nominal significance level in this sample. These results indicate alterations in dopamine-innervated regions (in the vmPFC and NAcc) in heroin addiction. For the first time we demonstrate lower IFG grey matter volume specifically in cocaine compared with heroin use disorder, suggesting a signature of reduced inhibitory control, which remains to be tested directly using select behavioural measures. Overall, results suggest substance-specific volumetric changes in human psychostimulant or opiate addiction, with implications for fine-tuning biomarker and treatment identification by primary drug of abuse.

In utero exposure to ADHD medication and long-term offspring outcomes

Attention Deficit Hyperactivity Disorder (ADHD) medication is increasingly being used during pregnancy. Concerns have been raised as to whether ADHD medication has long-term adverse effects on the offspring. The authors investigated whether in utero exposure to ADHD medication was associated with adverse long-term neurodevelopmental and growth outcomes in offspring. The population-based cohort study in the Danish national registers included 1,068,073 liveborn singletons from 1998 to 2015 followed until any developmental diagnosis, death, emigration, or December 31, 2018. Children of mothers who continued ADHD medication (methylphenidate, amphetamine, dexamphetamine, lisdexamphetamine, modafinil, atomoxetine, clonidine) during pregnancy and children of mothers who discontinued ADHD medication before pregnancy were compared using Cox regression. Main outcomes were neurodevelopmental psychiatric disorders, impairments in vision or hearing, epilepsy, seizures, or growth impairment during childhood or adolescence. In total, 898 children were exposed to ADHD medication during pregnancy compared to 1270 children whose mothers discontinued ADHD medication before pregnancy. After adjustment for demographic and psychiatric characteristics of the mother, no increased risk of any offspring developmental disorders was found combined (aHR 0.97, 95% CI 0.81 to 1.17) or for separate subcategories. Similarly, no increased risk was found for any sub-categories of outcomes in the negative control or sibling controlled analyses. Neurodevelopment and growth in offspring do not differ based on antenatal exposure to ADHD medication. These findings provide reassurance for women with ADHD who depend on ADHD medication for daily functioning and who consider continuing medication in pregnancy.

Prenatal exposure to a natural disaster and early development of psychiatric disorders during the preschool years: stress in pregnancy study

BACKGROUND

Growing evidence shows an association between in utero exposure to natural disasters and child behavioral problems, but we still know little about the development of specific psychopathology in preschool-aged children.

METHODS

Preschool children (n = 163, mean age = 3.19, 85.5% racial and ethnic minorities) and their parents (n = 151) were evaluated annually at ages 2-5 to assess the emergence of psychopathology using the Preschool Age Psychopathological Assessment (PAPA), a parent-report structured diagnostic interview developed for preschool-age children. Sixty-six (40.5%) children were exposed to Sandy Storm (SS) in utero and 97 (59.5%) were not. Survival analysis evaluated patterns of onset and estimated cumulative risks of psychopathology among exposed and unexposed children, in total and by sex. Analyses were controlled for the severity of objective and subjective SS-related stress, concurrent family stress, and demographic and psychosocial confounders, such as maternal age, race, SES, maternal substance use, and normative prenatal stress.

RESULTS

Exposure to SS in utero was associated with a substantial increase in depressive disorders (Hazard Ratio (HR) = 16.9, p = .030), anxiety disorders (HR = 5.1, p < .0001), and attention-deficit/disruptive behavioral disorders (HR = 3.4, p = .02). Diagnostic rates were elevated for generalized anxiety disorder (GAD; HR = 8.5, p = .004), attention-deficit/hyperactivity disorder (ADHD; HR = 5.5, p = .01), oppositional-defiant disorder (ODD; HR = 3.8, p = .05), and separation-anxiety disorder (SAD; HR = 3.5, p = .001). Males had distinctively elevated risks for attention-deficit/disruptive behavioral disorders (HR = 7.8, p = .02), including ADHD, CD, and ODD, whereas females had elevated risks for anxiety disorders (HR = 10.0, p < .0001), phobia (HR = 2.8, p = .02) and depressive disorders (HR = 30.0, p = .03), including SAD, GAD, and dysthymia.

CONCLUSIONS

The findings demonstrate that in utero exposure to a major weather-related disaster (SS) was associated with increased risk for psychopathology in children and provided evidence of distinct psychopathological outcomes as a function of sex. More attention is needed to understand specific parent, child, and environmental factors which account for this increased risk, and to develop mitigation strategies.

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.

Characterisation of seven medications approved for attention-deficit/hyperactivity disorder using in vitro models of hepatic metabolism

The metabolism of most medications approved for the treatment of attention deficit/hyperactivity disorder (ADHD) is not fully understood.In vitro studies using cryopreserved, plated human hepatocytes (cPHHs) and pooled human liver microsomes (HLMs) were performed to more thoroughly characterise the metabolism of several ADHD medications.The use of enzyme-specific chemical inhibitors indicated a role for CYP2D6 in atomoxetine (ATX) metabolism, and roles for CYP3A4/5 in guanfacine (GUA) metabolism.The 4-hydroxy-atomoxetine and N-desmethyl-atomoxetine pathways represented 98.4% and 1.5% of ATX metabolism in cPHHs, respectively. The 3-OH-guanfacine pathway represented at least 2.6% of GUA metabolism in cPHHs, and 71% in HLMs.The major metabolising enzyme for methylphenidate (MPH) and dexmethylphenidate (dMPH) could not be identified using these methods because these compounds were too unstable. Hydrolysis of these medications was spontaneous and did not require the presence of protein to occur.Clonidine (CLD), amphetamine (AMPH), and dextroamphetamine (dAMPH) did not deplete substantially in cPHHs nor HLMs, suggesting that these compounds may not undergo considerable hepatic metabolism. The major circulating metabolites of AMPH and dAMPH (benzoic acid and hippuric acid) were not observed in either system, and therefore could not be characterised. Additionally, inhibition experiments suggested a very minimal role for CYP2D6 in CLD and AMPH metabolism.

Clinically Meaningful Improvements in Early Morning and Late Afternoon/Evening Functional Impairment in Children with ADHD Treated with Delayed-Release and Extended-Release Methylphenidate

OBJECTIVE

The Before School Functioning Questionnaire and Parent Rating of Evening and Morning Behavior-Revised assess early morning (BSFQ, PREMB-R AM subscale) and late afternoon/evening (PREMB-R PM subscale) functional impairment in children with ADHD. Clinically meaningful improvements were identified and applied to a trial of delayed-release and extended-release methylphenidate (DR/ER-MPH) in children with ADHD (NCT02520388) to determine if the statistically-determined improvements in functional impairment were also clinically meaningful.

METHOD

Clinically meaningful improvements in BSFQ/PREMB-R were established post hoc by receiver operating characteristics curves, using anchors of Clinical Global Impression-Improvement (CGI-I) = 1 and CGI-I ≤ 2. Percentages of participants achieving these thresholds were calculated.

RESULTS

Thresholds for CGI-I = 1/CGI-I ≤ 2, respectively, were 27/20 (BSFQ), 5/3 (PREMB-R AM), and 9/5 (PREMB-R PM)-point decreases. More children achieved clinically meaningful improvements with DR/ER-MPH versus placebo (all p < .05).

CONCLUSION

DR/ER-MPH increased proportions of children achieving clinically meaningful improvements in BSFQ and PREMB-R.

Variable Patterns of Remission From ADHD in the Multimodal Treatment Study of ADHD

OBJECTIVE

It is estimated that childhood attention deficit hyperactivity disorder (ADHD) remits by adulthood in approximately 50% of cases; however, this conclusion is typically based on single endpoints, failing to consider longitudinal patterns of ADHD expression. The authors investigated the extent to which children with ADHD experience recovery and variable patterns of remission by adulthood.

METHODS

Children with ADHD (N=558) in the Multimodal Treatment Study of ADHD (MTA) underwent eight assessments over follow-ups ranging from 2 years (mean age, 10.44 years) to 16 years (mean age, 25.12 years) after baseline. The authors identified participants with fully remitted, partially remitted, and persistent ADHD at each time point on the basis of parent, teacher, and self-reports of ADHD symptoms and impairment, treatment utilization, and substance use and mental disorders. Longitudinal patterns of remission and persistence were identified that considered context and timing.

RESULTS

Approximately 30% of children with ADHD experienced full remission at some point during the follow-up period; however, a majority of them (60%) experienced recurrence of ADHD after the initial period of remission. Only 9.1% of the sample demonstrated recovery (sustained remission) by study endpoint, and only 10.8% demonstrated stable ADHD persistence across study time points. Most participants with ADHD (63.8%) had fluctuating periods of remission and recurrence over time.

CONCLUSIONS

The MTA findings challenge the notion that approximately 50% of children with ADHD outgrow the disorder by adulthood. Most cases demonstrated fluctuating symptoms between childhood and young adulthood. Although intermittent periods of remission can be expected in most cases, 90% of children with ADHD in MTA continued to experience residual symptoms into young adulthood.

Long-Term Treatment With Extended-Release Methylphenidate Treatment in Children Aged 4 to <6 Years

OBJECTIVE

To investigate long-term (12-month) safety and symptom control of extended-release methylphenidate (MPH-MLR) in children aged 4 to <6 years after treatment optimization.

METHOD

A total of 90 children aged 4 to <6 years with attention-deficit/hyperactivity disorder (ADHD) were enrolled from 2 MPH-MLR studies. Treatment-emergent adverse events (TEAEs) and ADHD symptom control were assessed in the safety population (n = 89) and modeled with mixed model analyses.

RESULTS

Most TEAEs (89.9%) were rated by investigators as of mild or moderate severity. One serious AE was reported (unrelated to study drug). Ten children discontinued because of TEAEs. Two discontinued because of weight loss; no significant increase in the rate of underweight children from baseline to endpoint was observed. Overall, 18% lost weight and 18% reported decreased appetite. Weight and height z scores and obesity rates decreased significantly from baseline to endpoint. Insomnia was reported (9%); none of these children discontinued. Sleep quality did not change significantly. Hypertension was reported (6.7%); none of these children dropped out. Diastolic, but not systolic, blood pressure increased significantly during the follow-up. Control of ADHD symptoms was maintained throughout follow-up.

CONCLUSION

These data contribute to the understanding of the long-term safety of an extended-release stimulant in children 4 to <6 years of age. The observed risk of a TEAE-related discontinuation was ∼11%. TEAEs were not dose related, and most were of mild to moderate severity. Symptom control was maintained through the year-long study.

CLINICAL TRIAL REGISTRATION INFORMATION

A 12-Month Open Label Safety Study of Aptensio XR® in Children Ages 4-5 Years Diagnosed With ADHD (EF004); https://clinicaltrials.gov; NCT02677519.

Prescription Stimulant Nonmedical Use Among Adolescents Evaluated for Substance Use Disorder Treatment (CHAT™)

Objective: The purpose of the present study was to characterize prescription stimulant non-medical use (NMU) in adolescents between the ages of 13 and 18 years seeking treatment for substance use disorder (SUD) with the Comprehensive Health Assessment Tool for Teens (CHAT™). Method: Adolescents being evaluated for SUD treatment between Q1 2010 and Q3 2017 (n = 20,189) completed the CHAT™. Results: About 4.3% of the sample (N = 867) of adolescents in SUD treatment reported past 30-day prescription stimulant NMU. Compared to those without past 30-day prescription stimulant NMU, more reported a lifetime diagnosis of learning disorder or ADHD, more took medication for emotional, behavioral, or learning disorders, received past-month inpatient treatment, or were currently not enrolled in school. Prescription stimulants were most often taken orally for NMU, however, approximately half reported using alternate routes of administration, the most prominent of which was intranasal use. Conclusion: About 4.3% of adolescents in SUD treatment evaluation reported past 30-day prescription stimulant NMU. Greater percentages of lifetime learning disorder, medication use, past-month inpatient treatment, school unenrollment, and overall substance misuse were associated with prescription stimulant NMU, as were alternate routes of administration. These data reveal an ongoing, persistent level of past-30-day NMU of prescription stimulants among adolescents being evaluated for SUD treatment.

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.

The World Federation of ADHD International Consensus Statement: 208 Evidence-based conclusions about the disorder

BACKGROUND

Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base.

METHODS

We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder.

RESULTS

We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents.

CONCLUSIONS

Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.

Neurobiological Basis of Reinforcement-Based Decision-Making in Adults With ADHD Treated With Lisdexamfetamine Dimesylate

Background: The objective of this study was to examine changes in the activation of the brain reward system following treatment with lisdexamfetamine (LDX) vs. placebo (PL) as a function of clinical improvement in attention deficit/hyperactivity disorder (ADHD) symptoms. Methods: Twenty adults with ADHD were included in a randomized cross-over study. Participants underwent two functional magnetic resonance imaging (fMRI) scans, after receiving 3 to 5 weeks of treatment with both LDX and PL. During scanning, participants performed the passive-avoidance learning task to assess reward-related learning using computational variables (e.g., estimated value and prediction error). Pre-treatment to post-treatment symptom change was assessed via the ADHD Rating Scale (ADHD-RS). The imaging contrasts were Object Choose or Object Refuse during the object choice component of the task, modulated by expected value (reward vs. nonreward cue), and Reward vs. Punishment during feedback, modulated by prediction error (expected vs. actual outcome). To address the primary objective, we performed group-level mass univariate analyses between pre-treatment to post-treatment percent change of the ADHD-RS total scores and the four contrast images under the choice and feedback conditions, with significance set at a whole-brain voxel-wise threshold of p < .05 with family-wise error (FWE) correction and an extent (cluster) threshold of 50 contiguous voxels. Results: Improvement in ADHD symptoms was accompanied by significant increases of brain activation during the Object Refuse, Reward and Punishment contrasts in a widespread network including left caudate and putamen, and right orbitofrontal cortex (i.e., reward-related signaling) and left middle frontal, superior frontal, and precentral gyri (i.e., executive control). Conclusions: These findings are the first to show that the increase in responsiveness of systems engaged in reward processing with LDX treatment is positively related to symptom improvement. Results support the hypothesis that LDX treatment may restore balance to dysfunction (e.g., hypoactivation) within the brain reward circuitry in adults with ADHD.

A Placebo-Controlled Trial of Lisdexamfetamine in the Treatment of Comorbid Sluggish Cognitive Tempo and Adult ADHD

Objective: To examine the efficacy of lisdexamfetamine (LDX) versus placebo on behavioral attributes of sluggish cognitive tempo (SCT) in adults with attention-deficit/hyperactivity disorder (ADHD) and SCT. Methods: In a randomized crossover trial conducted January 2016-April 2018, 38 adults with DSM-5 ADHD (via the Adult ADHD Clinical Diagnostic Scale v1.2) and SCT were recruited at 2 academic medical centers and assessed for symptoms of ADHD, SCT, executive function deficits, and functional impairment at baseline and weekly during treatment. Participants received 4 weeks of treatment with either LDX (30-70 mg/d; mean = 59.1 ± 14.8 mg/d) or matching placebo (mean = 66.6 ± 9.1 mg/d) with a 2-week washout before switching to the other arm. The ADHD Rating Scale and Barkley Adult ADHD Rating Scale-IV SCT subscale were coprimary outcome measures. Results: There were moderately large treatment effects of LDX vs placebo on SCT ratings in both treatment periods (block 1 effect size = 0.68; block 2 effect size = 0.61), which reached significance only in block 1 owing to carryover effects of the first treatment epoch into the second. Significant effects were also seen for LDX over placebo in ADHD, executive function deficit, and functional impairment ratings, without order effects; no site differences were seen except on the Global Executive Complex score of the Behavior Rating Inventory of Executive Function-Adult Version. No moderating effects of sex, age, race, and ethnicity were seen. Conclusions: Adults with ADHD and comorbid SCT had significant improvement after LDX vs placebo in ratings of SCT, ADHD, executive function deficits, and functional impairment. This is the first study to show improvement in SCT after stimulant therapy in adults with ADHD. Trial Registration: ClinicalTrials.gov identifier: NCT02635035.

Viloxazine in the Management of CNS Disorders: A Historical Overview and Current Status

Viloxazine has a long history of clinical use in Europe as an antidepressant, and has recently been repurposed into an extended-release form for the treatment of attention-deficit/hyperactivity disorder in the USA. An immediate-release formulation was approved for the treatment of depression in the UK in 1974, and was subsequently marketed there and in several European countries for 30 years with no major safety concerns. In contrast to first-generation antidepressants (e.g., tricyclic antidepressants, monoamine oxidase inhibitors), viloxazine was associated with a relatively low risk for cardiotoxicity. Gastrointestinal symptoms were the most commonly reported side effects. The therapeutic effects of viloxazine are thought to be primarily the result of its action as a norepinephrine reuptake inhibitor, although in vitro and preclinical in vivo animal data suggest that viloxazine may also impact the serotoninergic system. This review summarizes the evolving knowledge of viloxazine based on information from previously published preclinical and clinical investigations, and acquired unpublished historical study reports from both open-label and blinded controlled clinical trials. We review the chemical properties, mechanism of action, safety, and tolerability across these studies, and discuss the contemporary rationale for the development of this agent as an extended-release oral formulation for the treatment of attention-deficit/hyperactivity disorder.

Effect of Delayed-Release and Extended-Release Methylphenidate on Caregiver Strain and Validation of Psychometric Properties of the Caregiver Strain Questionnaire: Results from a Phase 3 Trial in Children with Attention-Deficit/Hyperactivity Disorder

Objectives: Inadequately controlled symptoms and associated impaired functioning have a significant negative impact on caregivers of children with attention-deficit/hyperactivity disorder (ADHD). This study aimed to assess the impact of evening-dosed, delayed-release and extended-release methylphenidate (DR/ER-MPH) treatment on caregiver strain, measured by the Caregiver Strain Questionnaire (CGSQ), and present post hoc psychometric analyses assessing the reliability and validity of the CGSQ, its ability to detect change (responsiveness), and to derive responder definitions. Methods: The CGSQ was an exploratory efficacy endpoint in a phase 3, 3-week, randomized, double-blind, multicenter, placebo-controlled, forced-dose titration trial of DR/ER-MPH in children aged 6-12 years with ADHD (NCT02520388). Psychometric properties of the CGSQ evaluated post hoc included internal consistency using Cronbach's alpha; test/retest reliability using intraclass correlation coefficients (ICCs); construct validity (known groups and convergent/divergent validity); responsiveness to changes in assessments of ADHD severity (ADHD Rating Scale-IV [ADHD-RS-IV], Conners' Global Index-Parent [CGI-P], and Clinical Global Impression-Severity [CGI-S]/CGI-Improvement [CGI-I]); and meaningful change threshold (MCT) using receiver operating characteristic curves, which were used to compare response between DR/ER-MPH and placebo groups. Results: Randomized DR/ER-MPH (54.5) and placebo (54.9) groups had similar mean CGSQ scores at screening. Caregivers of children on DR/ER-MPH reported significant reductions in CGSQ scores after 3 weeks of DR/ER-MPH treatment versus placebo (least-squares mean: 41.2 vs. 49.1; p < 0.001). The CGSQ demonstrated strong internal consistency (Cronbach's alpha = 0.93) and good test/retest reliability (ICC = 0.72). Known groups, convergent/divergent validity, and responsiveness were demonstrated from relationships between the CGSQ and the CGI-S, ADHD-RS-IV, and CGI-P. The mean anchor-based MCT for CGSQ total score was estimated as -9.0 (DR/ER-MPH vs. placebo: 53.2% vs. 29.9% p = 0.003). Conclusions: CGSQ scores significantly decreased after 3 weeks of DR/ER-MPH treatment versus placebo, and the CGSQ was found to be a valid and reliable measure of strain in caregivers of children with ADHD. Clinical trial registration identification number: NCT02520388.

Non-medical Use of Prescription Stimulants Among College Students: Non-oral Routes of Administration, Risk Factors, Motivations, and Pathways

Introduction: Non-medical use (NMU) of prescription stimulant medications is a continuing public health concern. Stimulant medications prescribed for attention-deficit/hyperactivity disorder (ADHD) are widely available on college campuses, and, as a consequence, college students may have multiple opportunities to engage in prescription stimulant NMU. This online self-report survey examined prescription stimulant NMU among college students, including: (1) patterns of non-oral route of administration (ROA); (2) motivations for non-oral ROAs; and (3) retrospectively recalled pathways of initiation. Method: The survey sample was created from a pool of 3,379 respondents, who were matched to a sampling frame constructed from the 18-26-year-old, college student sample of the 2016 American Community Survey (ACS). About 14% (n = 486) from the overall pool were identified as college students with self-reported prescription stimulant NMU, all of whom completed the survey. The survey covered user characteristics, prescription and illicit substance use, age of first NMU, motivations for NMU, sources of procurement, and ROAs used. Results: Among 486 students reporting prescription stimulant NMU, 43% had a lifetime diagnosis of ADHD. More than 90% reported polysubstance use, with 55% using illicit substances other than marijuana. Slightly more than 2 in 5 (43.3%) reported using illicit substances prior to prescription stimulant NMU, 24.6% used both at the same age, and 32.0% engaged in NMU of prescription stimulants prior to using illicit substances. Prescription stimulant NMU preceded prescription opioid NMU 45% of the time. More than a quarter of those engaged in prescription stimulant NMU (27.9%) initiated prescription stimulants alone or at the same age as other drugs. Most prescription stimulant NMU was oral, however 23.0% reported any non-oral use: snorting (20.4%), smoking (6.0%)and/or injection (3.5%). Non-oral use was associated with being male, obtaining medication from a dealer, use to get high, and/or a substance use disorder diagnosis. Conclusions: Prescription stimulant NMU often occurs in the larger context of other substance use among college students. Injection, an under-researched route for prescription stimulants, was associated with male gender, history of substance use and higher likelihood of illicit substance use. Nearly a quarter of college student survey respondents reported use with non-oral routes, which is associated with other high-risk behaviors. Efforts to reduce non-oral prescription stimulant NMU in college students are warranted.

Polygenic risk score analysis revealed shared genetic background in attention deficit hyperactivity disorder and narcolepsy

Attention deficit hyperactive disorder (ADHD) is a highly heritable neurodevelopmental disorder, and excessive daytime sleepiness is frequently observed in ADHD patients. Excessive daytime sleepiness is also a core symptom of narcolepsy and essential hypersomnia (EHS), which are also heritable conditions. Psychostimulants are effective for the symptomatic control of ADHD (primary recommended intervention) and the two sleep disorders (frequent off-label use). However, the common biological mechanism for these disorders has not been well understood. Using a previously collected genome-wide association study of narcolepsy and EHS, we calculated polygenic risk scores (PRS) for each individual. We investigated a possible genetic association between ADHD and narcolepsy traits in the Hamamatsu Birth Cohort for mothers and children (HBC study) (n = 876). Gene-set enrichment analyses were used to identify common pathways underlying these disorders. Narcolepsy PRS were significantly associated with ADHD traits both in the hyperactivity domain (e.g., P-value threshold < 0.05, β [SE], 5.815 [1.774]; P = 0.002) and inattention domain (e.g., P-value threshold < 0.05, β [SE], 5.734 [1.761]; P = 0.004). However, EHS PRS was not significantly associated with either domain of ADHD traits. Gene-set enrichment analyses revealed that pathways related to dopaminergic signaling, immune systems, iron metabolism, and glial cell function involved in both ADHD and narcolepsy. Findings indicate that ADHD and narcolepsy are genetically related, and there are possible common underlying biological mechanisms for this relationship. Future studies replicating these findings would be warranted to elucidate the genetic vulnerability for daytime sleepiness in individuals with ADHD.

Post hoc analyses of response rates to pharmacological treatments in children and adolescents with attention-deficit/hyperactivity disorder

INTRODUCTION AND OBJECTIVES

Lack of consensus regarding how best to define treatment response hinders translation from trials to the clinic. These post hoc analyses examine three commonly used response criteria in six trials of lisdexamfetamine dimesylate (LDX) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Data from four short-term randomised controlled trials (RCTs) and two long-term open-label studies were analysed. Children and adolescents with ADHD received either dose-optimised (30-70 mg/day) or fixed-dose (70 mg/day) LDX. The RCTs included osmotic-release oral system methylphenidate (OROS-MPH) or atomoxetine (ATX) as a head-to-head comparator or as a reference treatment. Three definitions of response were used in these analyses: reductions of ⩾30% or ⩾50% in ADHD Rating Scale IV (ADHD-RS-IV) total score plus a Clinical Global Impressions - Improvement (CGI-I) score of 1 or 2, or an ADHD-RS-IV total score of ⩽18.

RESULTS

At the end point, LDX response rates for the least stringent criterion of ⩾30% reduction in ADHD-RS-IV total score plus a CGI-I score of 1 or 2 ranged from 69.6% to 82.6%. The proportion achieving the more stringent criterion of a reduction in ADHD-RS-IV total score of ⩾50% plus a CGI-I score of 1 or 2 at the end point ranged from 59.8% to 74.8%. An ADHD-RS-IV total score of ⩽18 at the end point was achieved by 56.7-79.9% of participants. Response rates remained stable throughout the long-term open-label studies.

CONCLUSIONS

Response rates were similar for the two more stringent response criteria. The less stringent criterion resulted in higher response rates and may include partial responders.

Randomized, Double-Blind, Placebo-Controlled, Flexible-Dose Titration Study of Methylphenidate Hydrochloride Extended-Release Capsules (Aptensio XR) in Preschool Children with Attention-Deficit/Hyperactivity Disorder

Objectives: To assess the efficacy and safety of a methylphenidate hydrochloride extended-release capsule (MPH-MLR) formulation in treating attention-deficit/hyperactivity disorder (ADHD) in preschool children. Methods: Children aged 4 to <6 years with qualifying ADHD Rating Scale Fourth Edition (ADHD-RS-IV) Preschool Version scores (≥90th percentile for age/gender) participated in four behavior management training (BMT) sessions or immediately entered (based on investigator assessment of symptom severity or previous participation) into a 6-week, open-label, flexible MPH-MLR dose optimization phase. After BMT, children with <30% improvement in ADHD-RS-IV score and ≥3 score on the Clinical Global Impression-Improvement (CGI-I) scale also entered the open-label period. All children began the open-label period with MPH-MLR 10 mg once daily; weekly adjustments permitted once-daily maximum of up to 40 mg. Children with ≥30% improvement in ADHD-RS-IV total score and a CGI-I score of 1-2 at open-label completion were randomized to their optimized dose of MPH-MLR or placebo for 2 weeks (double blind [DB]). Safety measures included adverse events (AEs), vital signs, and electrocardiograms. Results: Open-label enrollment was 119 children. Mean (SD) ADHD-RS-IV total scores at open-label start and open-label end was 40.8 (10.4) and 19.5 (11.1), respectively. Ninety children were enrolled in the DB phase. Mean (SD) ADHD-RS-IV total scores for the MPH-MLR and placebo group were similar at DB beginning and was 25.8 (14.6) and 34.9 (14.1), respectively, at DB end. Mean change from baseline in ADHD-RS-IV total score during DB was significantly greater in children randomized to placebo compared with MPH-MLR; least squares mean change difference from baseline was -11.2, p = 0.002. During open-label dosing, the most common AEs (≥10%) were decreased appetite, decreased weight, insomnia, hypertension, emotional disorder, and affect lability. Conclusion: Results demonstrate MPH-MLR efficacy in preschool children and a safety profile consistent with known AEs of methylphenidate when used for ADHD.

Characterizing the Placebo Response in Adults With ADHD

Objective: Several ADHD pharmacological trials reported high placebo response (PR) rates. This study aims to characterize the PR in adult ADHD. Method: A retrospective cohort analysis of the placebo arm (140 adults with ADHD, 18-55 yrs, M:F 46.4%-53.6%) of a 6-week randomized, multicenter, double-blind metadoxine study, using Conners' Adult ADHD Rating Scale (CAARS) and the Adult ADHD Self-Report Scale (ASRS), was conducted. Results: Pre-post changes in placebo-treated adults were significant for both the CAARS and ASRS, F(2.9, 404.5) = 61.2, p < .00001, F(2.8, 383.0) = 43.1, p < .00001, respectively. Less than half of the participants had a PR which began early in treatment and persisted; almost 50% had a variable, inconsistent PR. Conclusion: In the current sample, PR in adult ADHD was prominent on both symptom scales and the investigator-rater instrument. Therefore, using investigator ratings as a primary endpoint does not necessarily attenuate PR. Of note, about half of the PR is variable, suggesting unreliable determination of efficacy.

Family-Based Treatment for Anorexia Nervosa Symptoms in High-Risk Youth: A Partially-Randomized Preference-Design Study

This pilot study adapted family-based treatment (FBT) for youth with potentially prodromal anorexia nervosa (AN). Fifty-nine youth with clinically significant AN symptom constellations, but who never met full Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) (DSM-IV) criteria for AN, were enrolled in a partially randomized preference design study. Participants were offered randomization to FBT or supportive psychotherapy (SPT); those who declined to be randomized because of a strong treatment preference were entered into a parallel, non-randomized self-selected intervention study. Without accessing outcome data, an observational analysis with three diagnostic subclasses was designed based on AN symptom severity profiles, combining randomized and non-randomized participants, such that participants receiving FBT and SPT within each subclass were similar on key baseline characteristics. Outcomes of this pilot study were explored by calculating effect sizes for end-of-treatment values within each subclass, and also with a longitudinal mixed effect model that accounted for subclass. Weight trajectory was measured by percent expected body weight. Psychological outcomes were fear of weight gain, feeling fat, importance of weight, and importance of shape. Results show that the pattern of symptom observations over time was dependent on subclass of SAN (least symptomatic, moderately symptomatic, or most symptomatic) and on the target outcome variable category (weight or psychological). Results from this study, which should be considered in the context of the small sample sizes overall and within groups, can generate hypotheses for future, larger research trials on early treatment strategies. Feasibility findings illustrate how the innovative partially randomized preference design has potential broader application for AN intervention research.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT00418977.

Systematic Review: Nonmedical Use of Prescription Stimulants: Risk Factors, Outcomes, and Risk Reduction Strategies

OBJECTIVE

To review all literature on the nonmedical use (NMU) and diversion of prescription stimulants to better understand the characteristics, risk factors, and outcomes of NMU and to review risk-reduction strategies.

METHOD

We systematically searched PubMed, PsycINFO, and SCOPUS from inception to May 2018 for studies containing empirical data about NMU and diversion of prescription stimulants. Additional references identified by the authors were also assessed for inclusion.

RESULTS

A total of 111 studies met inclusion criteria. NMU and diversion of stimulants are highly prevalent; self-reported rates among population samples range from 2.1% to 58.7% and from 0.7% to 80.0%, respectively. A variety of terms are used to describe NMU, and most studies have examined college students. Although most NMU is oral, non-oral NMU also occurs. The majority of NMU is associated with no, or minor, medical effects; however, adverse medical outcomes, including death, occur in some individuals, particularly when administered by non-oral routes. Although academic and occupational performance enhancement are the most commonly cited motivations, there is little evidence that academic performance is improved by NMU in individuals without attention-deficit/hyperactivity disorder.

CONCLUSION

NMU of stimulants is a significant public health problem, especially in college students, but variations in the terms used to describe NMU and inconsistencies in the available data limit a better understanding of this problem. Further research is needed to develop methods to detect NMU, identify individuals at greatest risk, study routes of administration, and devise educational and other interventions to help reduce occurrence of NMU. Colleges should consider including NMU in academic integrity policies.

A Phase II Double-Blind, Placebo-Controlled, Efficacy and Safety Study of SPN-812 (Extended-Release Viloxazine) in Children With ADHD

Objective: The objective of this study is to evaluate efficacy and safety of SPN-812 (extended-release viloxazine) for ADHD in children aged 6 to 12 years. Method: In an 8-week study, 222 participants were randomized to placebo or SPN-812 100, 200, 300, or 400 mg/day. Measurements included ADHD Rating Scale (RS)-IV total score and Clinical Global Impression-Severity (CGI-S) and Clinical Global Impression-Improvement (CGI-I) scores. Safety assessments included laboratory and electrocardiogram (ECG) measurements, suicidality monitoring (Columbia-Suicide Severity Rating Scale), and adverse event (AE) reporting. Results: Significant improvements in ADHD-RS-IV total score were observed for 200, 300, and 400 mg dose groups versus placebo (p < .05; effect size [ES] = 0.547, 0.596, and 0.623). CGI-I score for the 300 mg group and CGI-S score for all SPN-812 groups except for 100 mg improved significantly (p < .05) versus placebo. The most frequent AEs (≥15%) were somnolence, headache, and decreased appetite. Conclusion: SPN-812 significantly reduced the severity of ADHD symptoms and was well tolerated. The efficacy and safety of SPN-812 are being investigated in Phase III trials.

Maladaptive Aggression: With a Focus on Impulsive Aggression in Children and Adolescents

Objective: Aggressive behavior is among the most common reasons for referral to psychiatric clinics and confers significant burden on individuals. Aggression remains poorly defined; there is currently no consensus on the best ways to recognize, diagnose, and treat aggression in clinical settings. In this review, we synthesize the available literature on aggression in children and adolescents and propose the concept of impulsive aggression (IA) as an important construct associated with diverse and enduring psychopathology. Methods: Articles were identified and screened from online repositories, including PubMed, PsychInfo, the Cochrane Database, EMBase, and relevant book chapters, using combinations of search terms such as "aggression," "aggressive behavio(u)r," "maladaptive aggression," "juvenile," and "developmental trajectory." These were evaluated for quality of research before being incorporated into the article. The final report references 142 sources, published from 1987 to 2019. Results: Aggression can be either adaptive or maladaptive in nature, and the latter may require psychosocial and biomedical interventions when it occurs in the context of central nervous system psychopathology. Aggression can be categorized into various subtypes, including reactive/proactive, overt/covert, relational, and IA. IA in psychiatric or neurological disorders is reviewed along with current treatments, and an algorithm for systematic evaluation of aggression in the clinical setting is proposed. Conclusions: IA is a treatable form of maladaptive aggression that is distinct from other aggression subtypes. It occurs across diverse psychiatric and neurological diagnoses and affects a substantial subpopulation. IA can serve as an important construct in clinical practice and has considerable potential to advance research.

Gender Effects in the Efficacy of Racemic Amphetamine Sulfate in Children with Attention-Deficit/Hyperactivity Disorder

Introduction

A laboratory classroom study in children aged 6–12 years with attention-deficit/hyperactivity disorder (ADHD) found that racemic amphetamine sulfate (RA-AMPH) significantly improved performance versus placebo from 45 min through 10 h post-dose (NCT01986062). A secondary analysis assessed gender as a potential moderator of response to treatment comparing the ADHD Rating Scale-IV (ADHD-RS-IV) and Swanson, Kotkin, Agler, M-Flynn and Pelham (SKAMP) rating scales.

Methods

After 8 weeks of open-label RA-AMPH dose optimization using improvement in ADHD-RS-IV symptoms as a guide, 97 subjects (38 females and 59 males) were randomized to the sequence of 2 weeks of double-blind treatment with the optimized dose of RA-AMPH followed by placebo or vice versa during a laboratory classroom day. Efficacy measures included the SKAMP and the Permanent Product Measure of Performance (PERMP). The average difference for RA-AMPH versus placebo was estimated using least-square (LS) means. Treatment interaction by gender was analyzed using a cross-sectional fixed-effects model.

Results

ADHD-RS-IV scores were comparable for males and females at study entry and at the end of open-label treatment. During double-blind treatment, LS mean scores significantly improved for both genders versus placebo on the SKAMP scale and the PERMP (average p < 0.0001 for all post-dose time points). Beginning at baseline, males had significantly higher (worse) SKAMP scores than females but not worse ADHD-RS-IV or PERMP scores.

Conclusion

Both genders responded well to treatment with RA-AMPH, with comparable onset and duration of effect. The ADHD-RS-IV and SKAMP scales both measure changes in attention and hyperactive-impulsive behavior, but the SKAMP scale also measures associated disruptive behaviors, such as frustration, lying, and interpersonal conflict, that are more characteristic of oppositional and conduct disorders and more prevalent in boys with ADHD. Therefore, the SKAMP may be more sensitive for measuring the range of symptoms of boys with ADHD than the ADHD-RS-IV.

Funding

Arbor Pharmaceuticals, LLC.

Distinguishing the efficacy and sedative effects of guanfacine extended release in children and adolescents with attention-deficit/hyperactivity disorder

The present study investigated whether symptom reduction in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) treated with guanfacine extended release (GXR) can be explained by sedative effects of the medication. Data from four double-blind, randomized, placebo-controlled, phase 3 trials of GXR monotherapy (1-7 mg/day; morning administration) in children (aged 6-12 years) and adolescents (aged 13-17 years) with ADHD were analyzed post hoc. Two studies used forced-dose titration and two used flexible-dose titration. Efficacy was determined using ADHD Rating Scale IV (ADHD-RS-IV) scores. Sedative treatment-emergent adverse events (TEAEs) included somnolence, sedation and hypersomnia. The proportion of responders (≥ 30% reduction in ADHD-RS-IV total score) increased from weeks 1 to 4 and remained stable to study endpoint. Sedative TEAEs generally peaked at the first week in which the target dose was achieved and then declined. In subgroup analyses, significant placebo-adjusted improvements in ADHD-RS-IV total scores were observed in participants without any sedative TEAEs in the forced-dose and flexible-dose studies (nominal p < 0.001). In addition, GXR was associated with significant improvements in both inattentive and hyperactive-impulsive symptoms, as assessed by the ADHD-RS-IV subscale scores (nominal p < 0.001) and by the ADHD-RS-IV total score in participants with different ADHD subtypes (nominal p < 0.05). Thus, the efficacy of GXR in children and adolescents with ADHD is not primarily due to sedation, although some contribution to symptom reduction cannot be excluded, especially early in treatment when rates of sedative TEAEs are at their highest.

Practitioner Review: Emotional dysregulation in attention-deficit/hyperactivity disorder - implications for clinical recognition and intervention

BACKGROUND

Because emotional symptoms are common in attention-deficit/hyperactivity disorder (ADHD) patients and associate with much morbidity, some consider it to be a core feature rather than an associated trait. Others argue that emotional symptoms are too nonspecific for use as diagnostic criteria. This debate has been difficult to resolve due, in part, to the many terms used to describe emotional symptoms in ADHD and to concerns about overlap with mood disorders.

METHODS

We sought to clarify the nature of emotional symptoms in ADHD by reviewing conceptual and measurement issues and by examining the evidence base regarding specificity of such symptoms for ADHD. We reviewed the various terms used to define emotional symptoms in ADHD, clarify how these symptoms are demarcated from mood disorders, and assess the possibility that symptoms of emotional impulsivity and deficient emotional self-regulation should be considered as core symptoms. We addressed psychiatric comorbidities, the effects of ADHD treatments on associated emotional dysregulation, and the utility of current rating scales to assess emotional symptoms associated with ADHD.

RESULTS

Emotional symptoms are common and persistent in youth and adults with ADHD. Although emotional symptoms are common in other psychiatric disorders, emotional impulsivity (EI), and deficient emotional self-regulation (DESR) may be sufficiently specific for ADHD to function as diagnostic criteria.

CONCLUSIONS

Emotional symptoms in ADHD cause clinically significant impairments. Although there is a solid theoretical rationale for considering EI and DESR to be core symptoms of ADHD, there is no consensus about how to define these constructs sin a manner that would be specific to the disorder. An instrument to measure EI and DESR which demarcates them from irritability and other emotional symptoms could improve the accuracy of diagnostic criteria for ADHD.

Childhood serotonergic function and early adult outcomes in youth with ADHD: A 15-year follow-up study

Longitudinal studies have shown that clinical precursors of antisocial personality disorder (ASPD) include attention-deficit/hyperactivity disorder (ADHD) and more notably comorbid ADHD and conduct disorder (CD). Despite existing evidence for the purported role of abnormal serotonergic function in aggressive youth and adults, little evidence exists on the role of serotonin in the progression from childhood disruptive behavior disorders to adult psychopathology, including ASPD. This study examined the relation between serotonergic function in children diagnosed with ADHD and the development of ASPD in early adulthood. We hypothesized that low serotonin response to a pharmacological probe in childhood would predict the development of adult ASPD. Towards this goal we divided 40 adults (M = 37, F = 3), ages 23-26 (m-24.57, sd-2.33) diagnosed with childhood ADHD into 2 groups: participants with (n = 21) and without (n = 19) ASPD. We used logistic regression to assess whether serotonergic measures in childhood assessed via prolactin and cortisol responses to a fenfluramine challenge, would selectively predict the development of ASPD in early adulthood. Logistic regression models showed that low central serotonergic response in childhood indexed by cortisol response significantly predicted adult ASPD (Wald = 4.427, p = .035) but not ADHD diagnosis in adulthood. Adults without ASPD had the highest serotonergic response whereas adults with adolescent ASPD (i.e. early onset ASPD) had the lowest response. Thus we provide new evidence of the link between low serotonergic function in childhood and the development of ASPD in adulthood, particularly for boys with adolescent onset of ASPD. These findings are relevant for understanding the contribution of childhood neurobiology to risk for later ASPD.

Reward-Based Learning as a Function of Severity of Substance Abuse Risk in Drug-Naïve Youth with ADHD

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is associated with elevated risk for later development of substance use disorders (SUD), specifically because youth with ADHD, similar to individuals with SUD, exhibit deficits in learning abilities and reward processing. Another known risk factor for SUD is familial history of substance dependence. Youth with familial SUD history show reward processing deficits, higher prevalence of externalizing disorders, and higher impulsivity scores. Thus, the main objective of this proof-of-concept study is to investigate whether risk loading (ADHD and parental substance use) for developing SUD in drug-naïve youth impacts reward-related learning.

METHODS

Forty-one drug-naïve youth, stratified into three groups: Healthy Controls (HC, n = 13; neither ADHD nor parental SUD), Low Risk (LR, n = 13; ADHD only), and High Risk (HR, n = 15; ADHD and parental SUD), performed a novel Anticipation, Conflict, and Reward (ACR) task. In addition to conventional reaction time (RT) and accuracy analyses, we analyzed computational variables including learning rates and assessed the influence of learned predictions of reward probability and stimulus congruency on RT.

RESULTS

The multivariate ANOVA on learning rate, congruence, and prediction revealed a significant main Group effect across these variables [F(3, 37) = 3.79, p = 0.018]. There were significant linear effects for learning rate (Contrast Estimate = 0.181, p = 0.038) and the influence of stimulus congruency on RTs (Contrast Estimate = 1.16, p = 0.017). Post hoc comparisons revealed that HR youth showed the most significant deficits in accuracy and learning rates, while stimulus congruency had a lower impact on RTs in this group. LR youth showed scores between those of the HC and HR youth.

CONCLUSION

These preliminary results suggest that deficits in learning and in adjusting to task difficulty are a function of increasing risk loading for SUD in drug-naïve youth. These results also highlight the importance of developing and applying computational models to study intricate details in behavior that typical analytic methodology may not be sensitive to.

Lisdexamfetamine Targets Amygdala Mechanisms That Bias Cognitive Control in Attention-Deficit/Hyperactivity Disorder

BACKGROUND

Prefrontal-limbic circuits that form the neural architecture for emotion to influence behavior have been implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD) and represent a potentially important target of medication treatment that has not been substantively evaluated. This study tested the effect of the psychostimulant prodrug lisdexamfetamine dimesylate on amygdala activation and connectivity during the emotional bias of response execution and inhibition.

METHODS

Twenty-five adults with ADHD were scanned twice with event-related functional magnetic resonance imaging while performing an emotional go/no-go task after 3 to 4 weeks of lisdexamfetamine treatment and 3 weeks off medication in a randomized, counterbalanced, hybrid crossover design. Drug, trial type, and face emotion (happy, sad, or neutral) were included as within-subjects factors in repeated measures analyses of activation and connectivity.

RESULTS

Lisdexamfetamine was associated with increased right amygdala activation and reduced psychophysiological interactions with the orbital aspect of the left inferior frontal gyrus specifically for responses to sad faces compared with placebo, but there was no effect on the accuracy of response execution or inhibition. The relative gain in right amygdala activation in response to sad faces for lisdexamfetamine was correlated with a reduction in symptoms of ADHD.

CONCLUSIONS

Treatment with lisdexamfetamine potentiates affective encoding in amygdala, purportedly via catecholaminergic mechanisms, but functionally disconnects the amygdala from inferior frontal regions that encode behavioral significance-resulting in reduced emotional bias of cognitive control. Pinpointing the neurophysiologic underpinnings of therapeutic improvement with lisdexamfetamine represents a first step in developing targeted approaches to treatment of ADHD.

C. Keith Conners (1933-2017)

Presents an obituary of C. Keith Conners (1933-2017) who passed away of heart failure in Durham, North Carolina, on July 6, 2017. Conners was a pioneer in attention-deficit/hyperactivity disorder (ADHD) research and treatment. (PsycINFO Database Record

A Double-Blind, Placebo-Controlled, Phase II Study to Determine the Efficacy, Safety, Tolerability and Pharmacokinetics of a Controlled Release (CR) Formulation of Mazindol in Adults with DSM-5 Attention-Deficit/Hyperactivity Disorder (ADHD)

BACKGROUND

Mazindol is under investigation for the treatment of attention-deficit/hyperactivity disorder (ADHD) because of its alertness-enhancing properties. A novel controlled-release (CR) formulation of mazindol was developed to allow once-daily dosing.

OBJECTIVE

The aim of this study was to evaluate the efficacy of mazindol CR in adults with ADHD.

DESIGN

We conducted a randomized, double-blind, placebo-controlled 6-week trial.

METHODS

Subjects diagnosed with ADHD using the Mini-International Neuropsychiatric Structured Interview (MINI) and with an ADHD Rating Scale, Diagnostic and Statistical Manual of Mental Disorders 5th Edition (ADHD-RS-DSM5) score ≥ 28 were randomized to receive placebo or 1-3 mg/day of mazindol for 6 weeks. The primary endpoint was the reduction from baseline in the ADHD-RS-DSM5 score on Day 42. Secondary endpoints were response rates defined by change in ADHD-RS-DSM5 (≥ 30 or ≥ 50% reduction) and dichotomized Clinical Global Impression-Improvement (CGI-I) score (1 or 2). An exploratory endpoint of functional impairment, as measured by the Target Impairment Scale, examined individualized deficits in specific settings. Safety, tolerability, and pharmacokinetics were assessed.

RESULTS

Eighty-five participants were randomized (n = 43 active, 42 placebo); 75 completed. Weekly ADHD-RS-DSM5 measurements after mazindol differed from placebo beginning at Day 7, with a least squares mean difference (active-placebo) of - 13.2 at Day 42 and an effect size of 1.09. For the 30% or more reduction in ADHD-RS-DSM5 (minimal response), a significant difference (active-placebo) was seen starting at Day 7 and continuing to Day 42. For the CGI-I (1 or 2) and for the 50% or more reduction in ADHD-RS-DSM5 (measures of excellent response), the differences began at Day 14 and continued to Day 42. Functional impairment was significantly different in the proportion achieving at least a 50% reduction in target impairment score (42.9% mazindol vs 11.9% placebo) by Day 42. Dry mouth, nausea, fatigue, heart rate (HR) increased, decreased appetite, and constipation were more prevalent for mazindol versus placebo. Overall, mazindol CR had minimal effects on blood pressure and small effects on HR.

CONCLUSION

Mazindol CR was efficacious in the treatment of adults with ADHD, with a large effect size, and was well tolerated, supporting the progression to phase III. (Clinicaltrials.gov Registration No. NCT02808104).

Efficacy and Safety of HLD200, Delayed-Release and Extended-Release Methylphenidate, in Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Evening-dosed HLD200 is a delayed-release and extended-release methylphenidate (DR/ER-MPH) formulation consisting of uniform, dual-layered microbeads with an inner drug-loaded core. DR/ER-MPH is designed to delay the initial release of drug by 8-10 hours, and thereafter, provide a controlled, extended drug release to target onset of effect upon awakening that lasts into the evening. This phase 3 study evaluated the safety and efficacy of DR/ER-MPH on symptoms and temporal at-home functional impairment in children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

This 3-week, randomized, double-blind, multicenter, placebo-controlled, parallel-group, forced-dose titration trial evaluated DR/ER-MPH (40-80 mg/day) in children aged 6-12 years with ADHD. Primary efficacy endpoint was the ADHD rating scale-IV (ADHD-RS-IV), and the key secondary endpoints were the Before-School Functioning Questionnaire (BSFQ), and Parent Rating of Evening and Morning Behavior-Revised, morning (PREMB-R AM) and evening (PREMB-R PM). Safety measures included spontaneously reported treatment-emergent adverse events (TEAEs) and two TEAEs of special interest, appetite suppression and insomnia (with direct questioning on sleep disturbance).

RESULTS

One hundred sixty-one participants were included in the intent-to-treat population (DR/ER-MPH, n = 81; placebo, n = 80). After 3 weeks, DR/ER-MPH achieved significant improvements versus placebo in ADHD symptoms (least-squares [LS] mean ADHD-RS-IV: 24.1 vs. 31.2; p = 0.002), and at-home early morning (LS mean BSFQ: 18.7 vs. 28.4; p < 0.001; LS mean PREMB-R AM: 2.1 vs. 3.6; p < 0.001) and late afternoon/evening (LS mean PREMB-R PM: 9.4 vs. 12.2; p = 0.002) functional impairment. Commonly reported TEAEs (≥10%) were insomnia and decreased appetite.

CONCLUSIONS

DR/ER-MPH was generally well tolerated and demonstrated significant improvements versus placebo in ADHD symptoms and at-home functional impairments in the early morning, late afternoon, and evening in children with ADHD.

Striatal Activation Predicts Differential Therapeutic Responses to Methylphenidate and Atomoxetine

OBJECTIVE

Methylphenidate has prominent effects in the dopamine-rich striatum that are absent for the selective norepinephrine transporter inhibitor atomoxetine. This study tested whether baseline striatal activation would predict differential response to the two medications in youth with attention-deficit/hyperactivity disorder (ADHD).

METHOD

A total of 36 youth with ADHD performed a Go/No-Go test during functional magnetic resonance imaging at baseline and were treated with methylphenidate and atomoxetine using a randomized cross-over design. Whole-brain task-related activation was regressed on clinical response.

RESULTS

Task-related activation in right caudate nucleus was predicted by an interaction of clinical responses to methylphenidate and atomoxetine (F_1,30 = 17.00; p < .001). Elevated caudate activation was associated with robust improvement for methylphenidate and little improvement for atomoxetine. The rate of robust response was higher for methylphenidate than for atomoxetine in youth with high (94.4% vs. 38.8%; p = .003; number needed to treat = 2, 95% CI = 1.31-3.73) but not low (33.3% vs. 50.0%; p = .375) caudate activation. Furthermore, response to atomoxetine predicted motor cortex activation (F_1,30 = 14.99; p < .001).

CONCLUSION

Enhanced caudate activation for response inhibition may be a candidate biomarker of superior response to methylphenidate over atomoxetine in youth with ADHD, purportedly reflecting the dopaminergic effects of methylphenidate but not atomoxetine in the striatum, whereas motor cortex activation may predict response to atomoxetine. These data do not yet translate directly to the clinical setting, but the approach is potentially important for informing future research and illustrates that it may be possible to predict differential treatment response using a biomarker-driven approach.

CLINICAL TRIAL REGISTRATION INFORMATION

Stimulant Versus Nonstimulant Medication for Attention Deficit Hyperactivity Disorder in Children; https://clinicaltrials.gov/; NCT00183391.

Prefrontal and parietal correlates of cognitive control related to the adult outcome of attention-deficit/hyperactivity disorder diagnosed in childhood

The protracted and highly variable development of prefrontal cortex regions that support cognitive control has been purported to shape the adult outcome of attention-deficit/hyperactivity disorder (ADHD). This neurodevelopmental model was tested in a prospectively followed sample of 27 adult probands who were diagnosed with ADHD in childhood and 28 carefully matched comparison subjects aged 21-28 years. Probands were classified with persistent ADHD or remitted ADHD. Behavioral and neural responses to the Stimulus and Response Conflict Task (SRCT) performed during functional magnetic resonance imaging (fMRI) were compared in probands and comparison subjects and in probands with persistent and remitted ADHD. Response speed and accuracy for stimulus, response, and combined conflicts did not differ across groups. Orbitofrontal, inferior frontal and parietal activation was lower in probands than comparison subjects, but only for combined conflicts, when demand for cognitive control was highest. Reduced activation for combined conflicts in probands was almost wholly attributable to the persistence of ADHD; orbitofrontal, inferior frontal, anterior cingulate and parietal activation was lower in probands with persistent ADHD than both probands with remitted ADHD and comparison subjects, but did not differ between probands with remitted ADHD and comparison subjects. These data provide the first evidence that prefrontal and parietal activation during cognitive control parallels the adult outcome of ADHD diagnosed in childhood, with persistence of symptoms linked to reduced activation and symptom recovery associated with activation indistinguishable from adults with no history of ADHD.

The Groundskeeper Gaming Platform as a Diagnostic Tool for Attention-Deficit/Hyperactivity Disorder: Sensitivity, Specificity, and Relation to Other Measures

OBJECTIVE

The purpose of this study was to assess the relative accuracies of the Conners' Brief Rating Scale, Parent Version, the Conners' Continuous Performance Test II (CPT II), and a novel interactive game called "Groundskeeper" to discriminate child psychiatric patients with and without attention-deficit/hyperactivity disorder (ADHD).

METHODS

We administered the three assessments to 113 clinically referred ADHD and non-ADHD patients who had been diagnosed with the Kiddie-Schedule of Affective Disorders and Schizophrenia- Present and Lifetime (K-SADS-PL), Version 19.

RESULTS

As measured by the area under the curve (AUC) statistic from receiver operating characteristic (ROC) analysis, the diagnostic accuracy of Groundskeeper (0.79) was as high as the accuracy of the Conners' parent rating of inattention (0.76) and better than the CPT II percent correct (0.62). Combining the three tests produced an AUC of 0.87. Correlations among the three measures were small and, mostly, not significant.

CONCLUSIONS

Our finding of similar diagnostic accuracies between Groundskeeper and the Conners' inattention scale is especially remarkable given that the Conners' inattention scale shares method variance with the diagnostic process. Although our work is preliminary, it suggests that computer games may be useful in the diagnostic process. This provides an important direction for research, given the objectivity of such measures and the fact that computer games are well tolerated by youth.

Extended-release guanfacine hydrochloride in 6-17-year olds with ADHD: a randomised-withdrawal maintenance of efficacy study

BACKGROUND

Extended-release guanfacine hydrochloride (GXR), a selective α2A-adrenergic agonist, is a nonstimulant medication for attention-deficit/hyperactivity disorder (ADHD). This phase 3, double-blind, placebo-controlled, randomised-withdrawal study evaluated the long-term maintenance of GXR efficacy in children/adolescents with ADHD.

METHODS

Children/adolescents (6-17 years) with ADHD received open-label GXR (1-7 mg/day). After 13 weeks, responders were randomised to GXR or placebo in the 26-week, double-blind, randomised-withdrawal phase (RWP). The primary endpoint was the percentage of treatment failure (≥50% increase in ADHD Rating Scale version IV total score and ≥2-point increase in Clinical Global Impression-Severity compared with RWP baseline, at two consecutive visits). The key secondary endpoint was time to treatment failure (TTF).

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01081145; EudraCT 2009-018161-12.

RESULTS

A total of 528 participants enrolled; 316 (59.8%) entered the RWP. Treatment failure occurred in 49.3% of the GXR and 64.9% of the placebo group (p = 0.006). TTF was significantly longer in GXR versus placebo (p = 0.003). GXR was well tolerated.

CONCLUSIONS

Guanfacine hydrochloride demonstrated long-term maintenance of efficacy compared with placebo in children/adolescents with ADHD. Implications of the placebo substitution design and findings with different ADHD medications are discussed.

Pharmacotherapy of Aggression in Child and Adolescent Psychiatric Disorders

OBJECTIVE

Aggression is a common, yet complex, behavioral complaint, and a frequent indication for referral to child and adolescent psychiatrist treatment. This article reviews the evidence supporting pharmacotherapy of aggression in youth, with a primary focus on impulsive aggression (the primary indication for this intervention). Relevant diagnostic considerations and consensus guidelines are discussed.

METHODS

Articles examining the role of medications in the treatment of aggression in youth with pathological aggression were identified using PubMed and MEDLINE® databases over the past 15 years (2000-2015); selected articles published prior to 2000 and deemed to be of high relevance were searched and also included. Search terms included: Aggression, aggressive, disruptive behavior, conduct, youth, children, and adolescents. Cited references were also searched for relevant articles.

RESULTS

There are a number of evidence-based medication treatments for aggression, which are generally best considered in the context of differential diagnosis and ongoing evidence-based psychosocial interventions. Impulsive aggression is generally considered the type of aggression most amenable to medication, but other aggression subtypes may also possibly respond to treatment. Medication classes with positive evidence include the psychostimulants and α-2 agonists (in the presence of attention-deficit/hyperactivity disorder [ADHD] and/or disruptive behavior disorders), mood stabilizing agents, and atypical antipsychotics. Published guidelines recommend systematic and adequate trials of medications in sequential order, to optimize response and minimize polypharmacy. Guidelines for safety monitoring are available for many of the medications used for aggression in youth, and are also discussed.

CONCLUSIONS

Aggression in children carries a high risk of poor outcomes, and, therefore, a better understanding of treatment options is a high priority. The available literature points to the importance of identifying the underlying disorder, when possible, and using this information to guide treatment selection. Future studies are needed to better inform the treatment of aggression across disorders, and the treatment of different aggression subtypes.