The Dextroamphetamine Transdermal System (d-ATS) was developed as an alternative to oral amphetamine (AMP) formulations for ADHD. In a pivotal study, d-ATS met primary and secondary efficacy endpoints for ADHD in children and adolescents. Study subjects wore d-ATS for 9 hours, and an improvement in Swanson, Kotkin, Agler, M-Flynn, and Pelham scale (SKAMP) total score was observed from 2 through 12 hours after application. Patients with ADHD may need varying durations of treatment for symptoms from day to day. This analysis describes the exposure-response (E-R) relationship for d-ATS and explores possible outcomes for wear times ≤9 hours under varying assumptions.

A population pharmacokinetic (PK) model was developed to describe AMP disposition following d-ATS administration. This model was used to construct a population pharmacokinetic/pharmacodynamic (PK/PD) model from SKAMP total score data from two pediatric clinical studies to characterize onset and duration of effect after d-ATS administration. The integrated PK/PD model was used to describe the d-ATS E-R relationship and simulate the potential onset and duration of effect of d-ATS in response to various removal times (when <9 hours) by utilizing SKAMP scores as the efficacy measure. Subject-level AMP PK and SKAMP profiles were simulated for d-ATS removal at 4–9 hours post-application under different assumptions for AMP absorption after early patch removal. Modifications were made to the original population PK model to simulate patch removal.

Data from 81 children and 41 adolescents, 6–17 years old, were included. The model provided a reasonable description of the SKAMP score over time, showing an initial decline ~2 hours after patch application. In approximately 50% of children and adolescents, the maximum decline in SKAMP scores was observed within the first 4 hours after patch application. Earlier simulated d-ATS removal times were associated with reduced systemic exposure and earlier return to near-baseline scores across the range of assumptions tested.

Under different assumptions, the graphs changed modestly but not dramatically. For example, with moderate/conservative assumptions, following a 9-hour wear time, SKAMP scores returned to within 90% of baseline value in ~49% of subjects by 12 hours and ~80% of subjects by 16 hours. Following a 4-hour wear time, percentages were ~74% by 12 hours and ~95% by 16 hours.

Simulation results suggest that the duration of d-ATS efficacy may be related to wear time, which can be adjusted according to treatment needs, consistent with published observations for another transdermal stimulant. The d-ATS patch provides the ability to control medication exposure by shortening wear time, allowing treatment duration to be individualized and optimized in ADHD patients who have varying schedules and needs.

Noven Pharmaceuticals, Inc.

A recent genome-wide association study (GWAS) identified 12 independent loci significantly associated with attention-deficit/hyperactivity disorder (ADHD). Polygenic risk scores (PRS), derived from the GWAS, can be used to assess genetic overlap between ADHD and other traits. Using ADHD samples from several international sites, we derived PRS for ADHD from the recent GWAS to test whether genetic variants that contribute to ADHD also influence two cognitive functions that show strong association with ADHD: attention regulation and response inhibition, captured by reaction time variability (RTV) and commission errors (CE).

The discovery GWAS included 19 099 ADHD cases and 34 194 control participants. The combined target sample included 845 people with ADHD (age: 8–40 years). RTV and CE were available from reaction time and response inhibition tasks. ADHD PRS were calculated from the GWAS using a leave-one-study-out approach. Regression analyses were run to investigate whether ADHD PRS were associated with CE and RTV. Results across sites were combined via random effect meta-analyses.

When combining the studies in meta-analyses, results were significant for RTV (R2 = 0.011, β = 0.088, p = 0.02) but not for CE (R2 = 0.011, β = 0.013, p = 0.732). No significant association was found between ADHD PRS and RTV or CE in any sample individually (p > 0.10).

We detected a significant association between PRS for ADHD and RTV (but not CE) in individuals with ADHD, suggesting that common genetic risk variants for ADHD influence attention regulation.

A growing body of research suggests that deficient emotional self-regulation (DESR) is common and morbid among attention-deficit/hyperactivity disorder (ADHD) patients. The main aim of the present study was to assess whether high and low levels of DESR in adult ADHD patients can be operationalized and whether they are clinically useful.

A total of 441 newly referred 18- to 55-year-old adults of both sexes with Diagnostic and Statistical Manual of Mental Disorders: Fifth Edition (DSM-5) ADHD completed self-reported rating scales. We operationalized DESR using items from the Barkley Current Behavior Scale. We used receiver operator characteristic (ROC) curves to identify the optimal cut-off on the Barkley Emotional Dysregulation (ED) Scale to categorize patients as having high- versus low-level DESR and compared demographic and clinical characteristics between the groups.

We averaged the optimal Barkley ED Scale cut-points from the ROC curve analyses across all subscales and categorized ADHD patients as having high- (N = 191) or low-level (N = 250) DESR (total Barkley ED Scale score ≥8 or <8, respectively). Those with high-level DESR had significantly more severe symptoms of ADHD, executive dysfunction, autistic traits, levels of psychopathology, and worse quality of life compared with those with low-level DESR. There were no major differences in outcomes among medicated and unmedicated patients.

High levels of DESR are common in adults with ADHD and when present represent a burdensome source of added morbidity and disability worthy of further clinical and scientific attention.

Mechanistic endophenotypes can inform process models of psychopathology and aid interpretation of genetic risk factors. Smaller total brain and subcortical volumes are associated with attention-deficit hyperactivity disorder (ADHD) and provide clues to its development. This study evaluates whether common genetic risk for ADHD is associated with total brain volume (TBV) and hypothesized subcortical structures in children.

Children 7–15 years old were recruited for a case–control study (N = 312, N = 199 ADHD). Children were assessed with a multi-informant, best-estimate diagnostic procedure and motion-corrected MRI measured brain volumes. Polygenic scores were computed based on discovery data from the Psychiatric Genomics Consortium (N = 19 099 ADHD, N = 34 194 controls) and the ENIGMA + CHARGE consortium (N = 26 577).

ADHD was associated with smaller TBV, and altered volumes of caudate, cerebellum, putamen, and thalamus after adjustment for TBV; however, effects were larger and statistically reliable only in boys. TBV was associated with an ADHD polygenic score [β = −0.147 (−0.27 to −0.03)], and mediated a small proportion of the effect of polygenic risk on ADHD diagnosis (average ACME = 0.0087, p = 0.012). This finding was stronger in boys (average ACME = 0.019, p = 0.008). In addition, we confirm genetic variation associated with whole brain volume, via an intracranial volume polygenic score.

Common genetic risk for ADHD is not expressed primarily as developmental alterations in subcortical brain volumes, but appears to alter brain development in other ways, as evidenced by TBV differences. This is among the first demonstrations of this effect using molecular genetic data. Potential sex differences in these effects warrant further examination.

Despite increased nonmedical use of ADHD prescription stimulants, there are limited data to inform selection of intranasal doses for abuse-potential evaluations. This study determined a dose of amphetamine sulfate that is tolerable and distinguishable from placebo on pharmacodynamic (PD) measures.

In this randomized, double-blind, placebo-controlled, dose-escalation study, healthy, nondependent, recreational stimulant users received a single intranasal dose of amphetamine sulfate (20, 30, or 40mg ; n=6 per group) or placebo (n=2 per group). PD and safety were assessed pre-dose and ≤24hours post-dose. Drug Liking was measured using a bipolar Visual Analogue Scale (VAS; 0–100). Dose selection criteria were complete dose insufflation (≥95%); demonstration of peak Drug Liking ≥75 points, and ≥15 points greater than placebo in ≥3 participants receiving active drug; and tolerability.

Peak Drug Liking criteria were met in the 20-, 30-, and 40-mg groups by 2, 0, and 6 participants, respectively. Mean (SD) peak Drug Liking was 62 (13.0), 71 (17.8), and 93 (8.7) for amphetamine sulfate versus 54 (3.5), 76 (34.6), and 51 (0) for placebo in the 20-, 30-, and 40-mg groups, respectively. Thirteen participants experienced mild AEs (n=1, 4, 6, and 1 in 20-, 30-, 40-mg, and placebo groups, respectively), there were no serious or clinically significant AEs. The most common AE was nostril burning sensation (active drug, n=7). There were no instances of an incompletely insufflateddose.

A 40-mg intranasal dose produced distinguishable PD effects and was well tolerated. This dose has been selected for further abuse-potential evaluations.

Funding Acknowledgements: This study was funded by Arbor Pharmaceuticals, LLC.

The Research Domain Criteria initiative was launched by the US National Institute of Mental Health to establish a multi-level framework for understanding psychological constructs relevant to human psychiatric disorders, and identified ‘effort valuation/willingness to work’ as a clinically useful construct worthy of further study. This construct encompasses the processes by which the cost(s) of obtaining an outcome are calculated, and the tendency to overcome response costs to obtain a reinforcer. The current study aims to examine effort valuation as a correlate of psychopathology in children and adults, and the moderating effects of sex on this relationship.

Participants were 1215 children aged 6–12 and their parents (n = 1044). All participants completed the Effort Expenditure for Rewards Task as a measure of effort expenditure. Child psychopathology was measured via the Child Behavior Checklist, while adult psychopathology was measured via the Adult Self Report. Additionally, the Social Adjustment Inventory for Children and Adolescents and Injury Behavior Checklist were used to examine child social impairments/problem behaviors.

In children, significant interactions between reward sensitivity and sex were observed in association with anxiety and thought problems, specifically at low reward sensitivity levels. In adults, main effects of effort expenditure were seen in drug and alcohol abuse, where higher effort was associated with higher degrees of abuse.

These results establish effort valuation as a relevant psychological construct for understanding psychopathology, but with different profiles of associated psychopathology across sex in children and adults.

Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with high rates of psychiatric disorders, including schizophrenia in up to 30% of individuals with the syndrome. Despite this, we know relatively little about trajectories and predictors of persistence of psychiatric disorders from middle childhood to early adulthood. Accordingly, we followed youth over four timepoints, every 3 years, to assess long-term trajectories of attention-deficit hyperactivity disorder (ADHD), anxiety, mood, and psychosis-spectrum disorders (PSDs), as well as medication usage.

Eighty-seven youth with 22q11DS and 65 controls between the ages of 9 and 15 years at the first timepoint (T1; mean age 11.88 ± 2.1) were followed for 9 years (mean age of 21.22 ± 2.01 years at T4). Baseline cognitive, clinical, and familial predictors of persistence were identified for each class of psychiatric disorders.

Baseline age and parent-rated hyperactivity scores predicted ADHD persistence [area under curve (AUC) = 0.81]. The presence of family conflict predicted persistence of anxiety disorders (ADs) whereas parent ratings of child internalizing symptoms predicted persistence of both anxiety and mood disorders (MDs) (AUC = 0.84 and 0.83, respectively). Baseline prodromal symptoms predicted persistent and emergent PSDs (AUC = 0.83). Parent-reported use of anti-depressants/anxiolytics increased significantly from T1 to T4.

Psychiatric, behavioral, and cognitive functioning during late childhood and early adolescence successfully predicted children with 22q11DS who were at highest risk for persistent psychiatric illness in young adulthood. These findings emphasize the critical importance of early assessments and interventions in youth with 22q11DS.

A recent family study of young adult males suggests a shared familial liability between attention-deficit/hyperactivity disorder (ADHD) and high body mass index (BMI), and a genome-wide meta-analysis reported a genetic correlation of 0.26 between ADHD and BMI. To date, it is unclear whether these findings generalize to the relationship between ADHD and clinically diagnosed obesity.

By linking the Swedish national registers, we identified 25 38 127 individuals born between 1973 and 2000, together with their siblings and cousins. The risk of clinical obesity in individuals with ADHD was compared with the risk in those without ADHD. The relative contributions of genetic and environmental factors to the association between ADHD and clinical obesity were examined via assessment of the familial co-aggregation of the two conditions and quantitative genetic analysis.

Individuals with ADHD were at an increased risk of clinical obesity compared with those without (risk difference 3.73%, 95% confidence interval (CI) 3.55–3.90%; risk ratio 3.05, 95% CI 2.95–3.15). Familial co-aggregation of ADHD and clinical obesity was detected and the strength of the co-aggregation decreased by decreasing genetic relatedness. The correlation between the liabilities to ADHD and clinical obesity can be entirely attributed to their genetic correlation (rg 0.30, 95% CI 0.17–0.44).

The association between ADHD and clinical obesity in adolescence and young adulthood can be entirely attributed to genetic underpinnings shared by the two conditions. Children with ADHD should be monitored for weight gain so that preventive measures can be taken for those on a suboptimal trajectory.

High intelligence may be associated with positive (adaptive, desired) outcomes, but may also come with disadvantages.

To contribute empirically to the debate concerning whether a trade-off in IQ scores exists in relation to attention-deficit hyperactivity disorder (ADHD) and related problems, suggesting that high intelligence – like low intelligence –increases the risk of ADHD.

Curves of the relation between IQ score and ADHD problems were fitted to questionnaire data (parent, teacher, self-report) in a population-based study of 2221 children and adolescents aged 10–12 years. Externalising and internalising problems were included for comparison purposes.

Higher IQ score was most strongly related to fewer attention problems, with more rater discrepancy in the high v. average IQ range. Attention problems – but only minimally hyperactivity/impulsivity problems – predicted functional impairment at school, also in the higher IQ range.

Attention problems in highly intelligent children are exceptional and affect school performance; they are therefore a reason for clinical concern.

To investigate whether specific symptoms of attention deficit hyperactivity disorder (ADHD) can help identify ADHD patients with mind wandering.

Subjects were adults ages 18–55 of both sexes (n=41) who completed the Mind-Wandering Questionnaire (MWQ) and the ADHD module of the Schedule for Affective Disorders and Schizophrenia for School-Age Children Epidemiologic Version. We used Spearman’s rank correlation and Pearson’s χ2 analyses to examine associations between the ADHD module and the MWQ and receiver operator characteristic (ROC) analyses to evaluate the diagnostic efficiency of the ADHD module.

Out of the three ADHD domains, the inattentive ADHD scores had the strongest association with the MWQ (total: r s=0.34, df=39, p=0.03; inattentive: r s=0.38, df=39, p=0.02; Hyperactive: r s=0.17, df=39, p=0.28). Correlation analyses between individual items on the ADHD module and the MWQ showed that two inattention items (‘failure to pay attention to detail’ and ‘trouble following instructions’) were positively associated with total scores on the MWQ (p=0.02). These two inattention items had the strongest association with the MWQ (r s=0.45, df=38, p=0.004). ROC analyses showed that the combined score of the two significant inattention items had the highest efficiency (AUC=0.71) in classifying high-level mind wanderers as defined by scores greater than the median split on the MWQ. The combined score of the two inattention items best identified high-level mind wanderers.

Results suggest a way to operationalise mind wandering using the symptoms of ADHD.

ADHD is a prevalent and highly heritable mental disorder associated with significant impairment, morbidity and increased rates of mortality. This combination of high prevalence and high morbidity/mortality seen in ADHD and other mental disorders presents a challenge to natural selection-based models of human evolution. Several hypotheses have been proposed in an attempt to resolve this apparent paradox. The aim of this study was to review the evidence for these hypotheses.

We conducted a systematic review of the literature on empirical investigations of natural selection-based evolutionary accounts for ADHD in adherence with the PRISMA guideline. The PubMed, Embase, and PsycINFO databases were screened for relevant publications, by combining search terms covering evolution/selection with search terms covering ADHD.

The search identified 790 records. Of these, 15 full-text articles were assessed for eligibility, and three were included in the review. Two of these reported on the evolution of the seven-repeat allele of the ADHD-associated dopamine receptor D4 gene, and one reported on the results of a simulation study of the effect of suggested ADHD-traits on group survival. The authors of the three studies interpreted their findings as favouring the notion that ADHD-traits may have been associated with increased fitness during human evolution. However, we argue that none of the three studies really tap into the core symptoms of ADHD, and that their conclusions therefore lack validity for the disorder.

This review indicates that the natural selection-based accounts of ADHD have not been subjected to empirical test and therefore remain hypothetical.

To examine the unique neuropsychological presentation in adults with high functioning autism spectrum disorders (HF-ASD) by comparison with adults with attention deficit hyperactivity disorder (ADHD).

Adults with ASD referred to a specialty clinic (n=26) were compared to two non-ASD groups with (n=52) and without (n=52) ADHD of similar age and sex.

No differences in IQ were found. Subjects with HF-ASD were significantly more impaired than both comparison groups in processing speed, cognitive flexibility and sight words. Subjects with HF-ASD were more impaired than controls in working memory, but not the ADHD group.

These findings suggest that there may be specific neuropsychological correlates of HF-ASD differing from ADHD that could have significant implications for identifying individuals at risk for ASD.