Cognitive Function of Children and Adolescents with Attention-Deficit/Hyperactivity Disorder in a 2-Year Open-Label Study of Lisdexamfetamine Dimesylate

BACKGROUND: SPD489-404 was the first 2-year safety study of lisdexamfetamine dimesylate in the treatment of attention-deficit/hyperactivity disorder in children and adolescents. In accordance with advice from the European Medicines Agency, assessment of cognitive function was a predefined safety outcome in SPD489-404. OBJECTIVE: The objective of this study was to assess cognitive function over 2 years in study SPD489-404, using the Cambridge Neuropsychological Test Automated Battery (CANTAB). METHODS: Participants aged 6-17 years received dose-optimised open-label lisdexamfetamine dimesylate (30, 50 or 70 mg/day) for 104 weeks. Cognition was assessed using four CANTAB tasks; Delayed Matching to Sample (DMS), Spatial Working Memory (SWM), Stop Signal Task (SST) and Reaction Time (RTI). Key and additional variables were pre-specified for each CANTAB task; groupwise mean percentage changes in key variables from baseline of > 5% were considered potentially clinically significant. RESULTS: All 314 enrolled participants received lisdexamfetamine dimesylate and were included in the safety population, and 191 (60.8%) completed the study. No potentially clinically significant deteriorations from baseline were observed in any key CANTAB variable over the 2 years of the study. Based on predefined thresholds, potentially clinically significant improvements from baseline were observed at 6 months (DMS median reaction time, mean per cent change, - 6.6%; SWM total between-search errors, - 22.8%; SST stop signal reaction time, -18.9%), and at the last on-treatment assessment (DMS median reaction time, - 6.5%; SWM total between-search errors, - 32.6%; SST stop signal reaction time, - 25.7%). CONCLUSIONS: Lisdexamfetamine dimesylate treatment for 2 years was not associated with deterioration of cognitive function in children and adolescents with attention-deficit/hyperactivity disorder. Although improvements in some cognitive measures were observed, lack of a control group makes interpretation of the findings difficult. Further studies of the impact of stimulants on cognition are required

Growth and Puberty in a 2-Year Open-Label Study of Lisdexamfetamine Dimesylate in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

BACKGROUND: Stimulant medications for the treatment of attention-deficit/hyperactivity disorder have a history of safe and effective use; however, concerns exist that they may adversely affect growth trajectories in children and adolescents. OBJECTIVE: The objective of this study was to evaluate the longer-term effects of lisdexamfetamine dimesylate on weight, height, body mass index and pubertal development in children and adolescents with attention-deficit/hyperactivity disorder. METHODS: Children and adolescents aged 6-17 years with attention-deficit/hyperactivity disorder took open-label lisdexamfetamine dimesylate (30, 50 or 70 mg/day) in this open-label 2-year safety and efficacy study. Safety evaluations included treatment-emergent adverse events, measurement of weight, height and body mass index, and self-reported pubertal status using Tanner staging. RESULTS: The safety analysis population comprised all enrolled participants (N = 314) and 191 (60.8%) completed the study. Weight decrease was reported as a treatment-emergent adverse event in 63 participants (20.1%) and two participants (0.6%) discontinued the study as a result of treatment-emergent adverse events of weight decrease. Growth retardation of moderate intensity was reported as a treatment-emergent adverse event for two participants. From baseline to the last on-treatment assessment, there were increases in mean weight of 2.1 kg (standard deviation 5.83) and height of 6.1 cm (standard deviation 4.90), and a body mass index decrease of 0.5 kg/m2 (standard deviation 1.72). Mean weight, height and body mass index z-scores decreased over the first 36 weeks of the study and then stabilised. Changes from baseline to the last on-treatment assessment in mean z-scores for weight, height and body mass index were significantly less than zero (- 0.51, - 0.24 and - 0.59, respectively; nominal p < 0.0001). The proportion of participants with a z-score of < - 1 ranged from 5.1% (baseline) to 22.1% (week 84) for weight, 8.2% (baseline) to 12.6% (week 96) for height, and 8.3% (baseline) to 28.8% (week 96) for body mass index. Thirteen participants (4.1%) shifted to a weight below the fifth percentile at the last on-treatment assessment from a higher weight category at baseline. At the last on-treatment assessment, most participants remained at their baseline Tanner stage or had shifted higher. CONCLUSIONS: Findings from this comprehensive examination of growth outcomes associated with lisdexamfetamine dimesylate treatment over 2 years were consistent with previous studies of stimulant medications. Whilst mean weight and height increased over the course of the study, there was a small but transient reduction in mean weight, height and body mass index z-scores. A small increase in the proportion of participants in the lowest weight and body mass index categories highlights the importance of the regular monitoring of weight and height. There was no evidence of delayed onset of puberty. CLINICALTRIALS. GOV IDENTIFIER: NCT01328756

Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders

Health-related quality of life and functional outcomes from a randomized-withdrawal study of long-term lisdexamfetamine dimesylate treatment in children and adolescents with attention-deficit/hyperactivity disorder

BACKGROUND: The stimulant prodrug lisdexamfetamine dimesylate (LDX) is an effective and generally well tolerated treatment for the symptoms of attention-deficit/hyperactivity disorder (ADHD). Positive impacts of LDX on health-related quality of life and functional impairment have previously been demonstrated in a 7-week, randomized, double-blind, placebo-controlled, phase III study in children and adolescents in Europe. Maintenance of these broad benefits, as well as symptomatic control, is a key goal of long-term management of ADHD. OBJECTIVE: Secondary objectives of this multinational study in children and adolescents with ADHD were to assess the long-term maintenance of effectiveness of LDX in improving health-related quality of life and reducing functional impairment, as gauged using the Child Health and Illness Profile-Child Edition: Parent Report Form (CHIP-CE: PRF) and the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P), respectively. METHODS: Patients aged 6-17 years with diagnosed ADHD and a baseline ADHD Rating Scale IV total score of at least 28 were enrolled from the previous European study and from US sites. Patients who completed an open-label LDX treatment period of at least 26 weeks were randomized (1:1) to continue on their optimized dose of LDX or to switch to placebo for a 6-week, double-blind, withdrawal period. Parents completed CHIP-CE: PRF and WFIRS-P questionnaires at weeks 0, 8 and 26 of the open-label period and at weeks 0 and 6 of the randomized-withdrawal period, or at early termination. The endpoint of each period was defined as the last visit with valid data. Effect sizes were the difference (LDX minus placebo) in least-squares (LS)-mean change from baseline to endpoint divided by root-mean-square error. P values were nominal and not adjusted for multiple comparisons. RESULTS: The open-label and randomized full analysis sets comprised 262 and 153 (LDX n = 76; placebo n = 77) patients, respectively. Mean pretreatment CHIP-CE: PRF T-scores were more than one standard deviation below the normative mean in four of the five domains, and there was significant improvement across all domains from baseline to endpoint of the open-label period. In the randomized-withdrawal period, LS-mean CHIP-CE: PRF T-scores deteriorated in all domains in the placebo group, but not in the LDX group. Compared with placebo, the effect of LDX was significant in the Risk Avoidance (effect size 0.829; p < 0.001), Achievement (0.696; p < 0.001) and Satisfaction (0.636; p < 0.001) domains. Mean pretreatment WFIRS-P scores were lowest in the Family domain and the Learning and School domain. WFIRS-P total score and scores in all domains improved significantly from baseline to endpoint of the open-label period. In the randomized-withdrawal period, LS-mean scores deteriorated in the placebo group but not in the LDX group. Compared with placebo, the effect of LDX was significant in the Family, Learning and School, and Risky Activities domains and in total (effect size 0.908; p < 0.001). CONCLUSIONS: Using parent-rated instruments, long-term maintenance of the beneficial effect of LDX in multiple domains of health-related quality of life and functional impairment was demonstrated by comparison of treatment continuation and withdrawal under randomized, double-blind, placebo-controlled conditions

International consensus statement for the screening, diagnosis, and treatment of adolescents with concurrent attention-deficit/hyperactivity disorder and substance use disorder

$\bf Background:$ Childhood attention-deficit/hyperactivity disorder (ADHD) is a risk factor for substance misuse and substance use disorder (SUD) in adolescence and (early) adulthood. ADHD and SUD also frequently co-occur in treatment-seeking adolescents, which complicates diagnosis and treatment and is associated with poor treatment outcomes. Research on the effect of treatment of childhood ADHD on the prevention of adolescent SUD is inconclusive, and studies on the diagnosis and treatment of adolescents with ADHD and SUD are scarce. Thus, the available evidence is generally not sufficient to justify robust treatment recommendations. $\bf Objective:$ The aim of the study was to obtain a consensus statement based on a combination of scientific data and clinical experience. $\bf Method:$ A modified Delphi study to reach consensus based upon the combination of scientific data and clinical experience with a multidisciplinary group of 55 experts from 17 countries. The experts were asked to rate a set of statements on the effect of treatment of childhood ADHD on adolescent SUD and on the screening, diagnosis, and treatment of adolescents with comorbid ADHD and SUD. $\bf Results:$ After 3 iterative rounds of rating and adapting 37 statements, consensus was reached on 36 of these statements representing 6 domains: general ($\it n$ = 4), risk of developing SUD ($\it n$ = 3), screening and diagnosis ($\it n$ = 7), psychosocial treatment ($\it n$ = 5), pharmacological treatment ($\it n$ = 11), and complementary treatments ($\it n$ = 7). Routine screening is recommended for ADHD in adolescent patients in substance abuse treatment and for SUD in adolescent patients with ADHD in mental healthcare settings. Long-acting stimulants are recommended as the first-line treatment of ADHD in adolescents with concurrent ADHD and SUD, and pharmacotherapy should preferably be embedded in psychosocial treatment. The only remaining no-consensus statement concerned the requirement of abstinence before starting pharmacological treatment in adolescents with ADHD and concurrent SUD. In contrast to the majority, some experts required full abstinence before starting any pharmacological treatment, some were against the use of stimulants in the treatment of these patients (independent of abstinence), while some were against the alternative use of bupropion. $\bf Conclusion:$ This international consensus statement can be used by clinicians and patients together in a shared decision-making process to select the best interventions and to reach optimal outcomes in adolescent patients with concurrent ADHD and SUD

Fronto-Striatal Glutamate in Autism Spectrum Disorder and Obsessive Compulsive Disorder

Autism spectrum disorders (ASDs) and obsessive compulsive disorder (OCD) are often comorbid with the overlap based on compulsive behaviors. Although previous studies suggest glutamatergic deficits in fronto-striatal brain areas in both disorders, this is the first study to directly compare the glutamate concentrations across the two disorders with those in healthy control participants using both categorical and dimensional approaches. In the current multi-center study (four centers), we used proton magnetic resonance spectroscopy in 51 children with ASD, 29 with OCD, and 53 healthy controls (aged 8-13 years) to investigate glutamate (Glu) concentrations in two regions of the fronto-striatal circuit: midline anterior cingulate cortex (ACC) and left dorsal striatum. Spectra were processed with Linear Combination Model. Group comparisons were performed with one-way analyses of variance including sex, medication use, and scanner site as covariates. In addition, a dimensional analysis was performed, linking glutamate with a continuous measure of compulsivity across disorders. There was a main group effect for ACC glutamate (p=0.019). Contrast analyses showed increased glutamate both in children with ASD and OCD compared with controls (p=0.007), but no differences between the two disorders (p=0.770). Dimensional analyses revealed a positive correlation between compulsive behavior (measured with the Repetitive Behavior Scale) and ACC glutamate (rho=0.24, p=0.03). These findings were robust across sites. No differences were found in the striatum. The current findings confirm overlap between ASD and OCD in terms of glutamate involvement. Glutamate concentration in ACC seems to be associated with the severity of compulsive behavior.Neuropsychopharmacology advance online publication, 14 December 2016; doi:10.1038/npp.2016.260