Do effects of methylphenidate on cognitive performance last beyond treatment? A randomized placebo-controlled trial in boys and men with ADHD.

Methylphenidate (MPH) is the first-choice pharmacological treatment for treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) across the lifespan. However, it is unclear whether MPH affects cognitive development, while recent (pre-) clinical studies suggest effects on the developing brain. The present randomized, placebo-controlled trial aims to determine whether MPH has short-term, age-dependent effects on cognitive performance in ADHD after a 1-week washout. Effects of 16 weeks MPH treatment were assessed after a one-week washout on cognitive functioning. Boys (age=10-12) and men (age=23-40) with ADHD were assigned to MPH treatment (boys n=25, men n=24) or placebo (boys n=25, men n=24). Outcome measures were working memory, response inhibition, response speed, episodic memory, and delay aversion. Differences in task performances over time (pre-, mid-, and post-treatment, following a 1-week wash-out) were compared between age and treatment conditions with mixed ANOVAs. MPH improved working memory and response speed, but only during treatment. No lasting age*treatment effects were observed post intervention. Overall, the results from the present randomized, placebo-controlled trial show that the effects of MPH on cognition do not extend past treatment in children or adults. While treatment with MPH improves cognition during treatment, these effects appear transient after 16-weeks of treatment. (Title trial: "Effects of methylphenidate on the developing brain"; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3103).

Effects of prolonged methylphenidate treatment on amygdala reactivity and connectivity: a randomized controlled trial in stimulant treatment-naive, male participants with ADHD.

Background: Problems with emotional processing are widely reported in individuals with attention-deficit/hyperactivity disorder (ADHD). Although methylphenidate (MPH) effectively alleviates inattention and hyperactivity symptoms in ADHD, its effects on emotional processing and internalizing symptoms have remained elusive. While we previously found that acute MPH administration modulated neural mechanisms underlying emotional processing in an age-dependent manner, the effects of prolonged administration remained unknown. Objectives: Therefore, we investigated: (i) whether prolonged MPH treatment influences neural substrates (amygdala reactivity and connectivity) of emotional processing, and (ii) whether these effects are modulated by age. Methods: The "effects of Psychotropic drugs On Developing brain-MPH" ("ePOD-MPH") randomized controlled trial was a 16-week double-blind, placebo-controlled, multi-center trial with MPH in 50 boys (10-12 years of age) and 49 men (23-40 years of age), all stimulant treatment-naive and diagnosed with ADHD. Participants performed an emotional face-matching task during functional magnetic resonance imaging. We assessed their symptoms of ADHD and internalizing symptoms at baseline, during the trial (8 weeks), and 1 week after the trial end (17 weeks). Results and Conclusions: We did not find effects of prolonged MPH treatment on emotional processing, as measured by amygdala reactivity and connectivity and internalizing symptoms in this trial with stimulant treatment-naive participants. This differs from our findings on emotional processing following acute MPH administration and the effects of prolonged MPH treatment on the dopamine system, which were both modulated by age. Interestingly, prolonged MPH treatment did improve ADHD symptoms, although depressive and anxiety symptoms showed a medication-independent decrease. Furthermore, our data indicate that baseline internalizing symptoms may be used to predict MPH treatment effects on ADHD symptoms, particularly in (male) adults with ADHD.

Effects of 16 Weeks of Methylphenidate Treatment on Actigraph-Assessed Sleep Measures in Medication-Naive Children With ADHD.

Methylphenidate (MPH) improves behavioral symptoms of attention-deficit/hyperactivity disorder (ADHD). Its effects on sleep, however, are insufficiently known, as trials with MPH in medication-naive children were so far restricted to relatively short trial durations. Here, we assessed effects of prolonged MPH treatment on sleep in medication-naive boys in a 16-weeks double-blind, placebo controlled, multicenter clinical trial with immediate-release MPH (ePOD-MPH trial, NTR3103). Seventy-five medication-naive boys, aged 10-12 years, were screened for eligibility using ADHD DSM-IV criteria. Sleep was assessed using actigraphy, diaries and questionnaires prior to randomization, in week 8, and 1 week after trial end. Fifty boys (mean age 11.4y, SD 0.9) were randomized to MPH or placebo. Linear mixed model analysis demonstrated a significant time-by-treatment interaction effect (p = 0.007) on sleep efficiency. Post-hoc analyses demonstrated that the two groups did not differ from each other (p = 0.94) during treatment (week 8), but that sleep efficiency was significantly improved in the MPH (p = 0.005), but not placebo group (p = 0.87) 1 week after trial end. The lack of MPH's negative effects on sleep during treatment differ from most previous studies and could be explained by the relatively long trial duration in our study and the medication-naive status of our sample; suggesting that evaluating sleep problems only shortly after treatment onset presents an incomplete picture, because it might not be representative for sleep quality after longer treatment periods. Our findings of improved sleep after trial end could be due to rebound effects or longer-term effects of MPH treatment and therefore require replication. CLINICAL TRIAL REGISTRATION: Central Committee on Research Involving Human Subjects (an independent registry, identifier NL34509.000.10) before enrollment of the first subject and The Netherlands National Trial Register, identifier NTR3103.

ADHD and maturation of brain white matter: A DTI study in medication naive children and adults.

Several diffusion tensor imaging (DTI) studies in attention deficit hyperactivity disorder (ADHD) have shown a delay in brain white matter (WM) development. Because these studies were mainly conducted in children and adolescents, these WM abnormalities have been assumed, but not proven to progress into adulthood. To provide further insight in the natural history of WM maturation delay in ADHD, we here investigated the modulating effect of age on WM in children and adults. 120 stimulant-treatment naive male ADHD children (10-12 years of age) and adults (23-40 years of age) with ADHD (according to DSM-IV; all subtypes) were included, along with 23 age and gender matched controls. Fractional anisotropy (FA) values were compared throughout the WM by means of tract-based spatial statistics (TBSS) and in specific regions of interest (ROIs). On both TBSS and ROI analyses, we found that stimulant-treatment naive ADHD children did not differ in FA values from control children, whereas adult ADHD subjects had reduced FA values when compared to adult controls in several regions. Significant age × group interactions for whole brain FA (p = 0.015), as well as the anterior thalamic radiation (p = 0.015) suggest that ADHD affects the brain WM age-dependently. In contrast to prior studies conducted in medicated ADHD children, we did not find WM alterations in stimulant treatment naïve children, only treatment-naïve adults. Thus, our findings suggest that the reported developmental delay in WM might appear after childhood, and that previously reported differences between ADHD children and normal developing peers could have been attributed to prior ADHD medications, and/or other factors that affect WM development, such as age and gender.

Age-dependent effects of acute methylphenidate on amygdala reactivity in stimulant treatment-naive patients with Attention Deficit/Hyperactivity Disorder.

In the present study, we investigate whether methylphenidate (MPH) affects emotional processing and whether this effect is modulated by age. We measured amygdala reactivity with functional Magnetic Resonance Imaging (fMRI) during processing of angry and fearful facial expressions in male stimulant treatment-naive patients with ADHD (N = 35 boys; N = 46 men) and 23 healthy control subjects (N = 11 boys; N = 12 men). In ADHD patients, we also measured amygdala reactivity 90min after an acute oral challenge with MPH (0.5mg/kg). Mean amygdala reactivity was analyzed for all subjects using a repeated measures analysis of variance (ANOVA). Whole-brain maps were analyzed for the patients only. At baseline, we found a age*diagnosis effect approaching significance (p = 0.05) in the right amygdala due to lower reactivity in children with Attention Deficit/Hyperactivity Disorder (ADHD) vs. controls (-31%), but higher reactivity in adults with ADHD vs. controls (+31%). MPH significantly reduced right amygdala reactivity in all patients, resulting in further reductions in children. In the left amygdala, reduction of amygdala reactivity was confined to adult ADHD patients whereas there was no change in children with ADHD. MPH-induced decrease of amygdala reactivity in adults might be a promising avenue for managing emotional dysregulation when replicated for chronic MPH treatment.

The child's perspective on discomfort during medical research procedures: a descriptive study.

OBJECTIVE: The evaluation of discomfort in paediatric research is scarcely evidence-based. In this study, we make a start in describing children's self-reported discomfort during common medical research procedures and compare this with discomfort during dental check-ups which can be considered as a reference level of a 'minimal discomfort' medical procedure. We exploratory study whether there are associations between age, anxiety-proneness, gender, medical condition, previous experiences and discomfort. We also describe children's suggestions for reducing discomfort. DESIGN: Cross-sectional descriptive study. SETTING: Paediatric research at three academic hospitals. PATIENTS: 357 children with and without illnesses (8-18 years, mean=10.6 years) were enrolled: 307 from paediatric research studies and 50 from dental care. MAIN OUTCOME MEASURES: We measured various generic forms of discomfort (nervousness, annoyance, pain, fright, boredom, tiredness) due to six common research procedures: buccal swabs, MRI scans, pulmonary function tests, skin prick tests, ultrasound imaging and venepunctures. RESULTS: Most children reported limited discomfort during the research procedures (means: 1-2.6 on a scale from 1 to 5). Compared with dental check-ups, buccal swab tests, skin prick tests and ultrasound imaging were less discomforting, while MRI scans, venepunctures and pulmonary function tests caused a similar degree of discomfort. 60.3% of the children suggested providing distraction by showing movies to reduce discomfort. The exploratory analyses suggested a positive association between anxiety-proneness and discomfort. CONCLUSIONS: The findings of this study support the acceptability of participation of children in the studied research procedures, which stimulates evidence-based research practice. Furthermore, the present study can be considered as a first step in providing benchmarks for discomfort of procedures in paediatric research.

Age-Dependent Effects of Methylphenidate on the Human Dopaminergic System in Young vs Adult Patients With Attention-Deficit/Hyperactivity Disorder: A Randomized Clinical Trial.

IMPORTANCE: Although numerous children receive methylphenidate hydrochloride for the treatment of attention-deficit/hyperactivity disorder (ADHD), little is known about age-dependent and possibly lasting effects of methylphenidate on the human dopaminergic system. OBJECTIVES: To determine whether the effects of methylphenidate on the dopaminergic system are modified by age and to test the hypothesis that methylphenidate treatment of young but not adult patients with ADHD induces lasting effects on the cerebral blood flow response to dopamine challenge, a noninvasive probe for dopamine function. DESIGN, SETTING, AND PARTICIPANTS: A randomized, double-blind, placebo-controlled trial (Effects of Psychotropic Drugs on Developing Brain-Methylphenidate) among ADHD referral centers in the greater Amsterdam area in the Netherlands between June 1, 2011, and June 15, 2015. Additional inclusion criteria were male sex, age 10 to 12 years or 23 to 40 years, and stimulant treatment-naive status. INTERVENTIONS: Treatment with either methylphenidate or a matched placebo for 16 weeks. MAIN OUTCOMES AND MEASURES: Change in the cerebral blood flow response to an acute challenge with methylphenidate, noninvasively assessed using pharmacological magnetic resonance imaging, between baseline and 1 week after treatment. Data were analyzed using intent-to-treat analyses. RESULTS: Among 131 individuals screened for eligibility, 99 patients met DSM-IV criteria for ADHD, and 50 participants were randomized to receive methylphenidate and 49 to placebo. Sixteen weeks of methylphenidate treatment increased the cerebral blood flow response to methylphenidate within the thalamus (mean difference, 6.5; 95% CI, 0.4-12.6; P = .04) of children aged 10 to 12 years old but not in adults or in the placebo group. In the striatum, the methylphenidate condition differed significantly from placebo in children but not in adults (mean difference, 7.7; 95% CI, 0.7-14.8; P = .03). CONCLUSIONS AND RELEVANCE: We confirm preclinical data and demonstrate age-dependent effects of methylphenidate treatment on human extracellular dopamine striatal-thalamic circuitry. Given its societal relevance, these data warrant replication in larger groups with longer follow-up. TRIAL REGISTRATION: identifier: NL34509.000.10 and trialregister.nl identifier: NTR3103.

The effects of Psychotropic drugs On Developing brain (ePOD) study: methods and design.

BACKGROUND: Animal studies have shown that methylphenidate (MPH) and fluoxetine (FLX) have different effects on dopaminergic and serotonergic system in the developing brain compared to the developed brain. The effects of Psychotropic drugs On the Developing brain (ePOD) study is a combination of different approaches to determine whether there are related findings in humans. METHODS/DESIGN: Animal studies were carried out to investigate age-related effects of psychotropic drugs and to validate new neuroimaging techniques. In addition, we set up two double-blind placebo controlled clinical trials with MPH in 50 boys (10-12 years) and 50 young men (23-40 years) suffering from ADHD (ePOD-MPH) and with FLX in 40 girls (12-14 years) and 40 young women (23-40 years) suffering from depression and anxiety disorders (ePOD-SSRI). Trial registration numbers are: Nederlands Trial Register NTR3103 and NTR2111. A cross-sectional cohort study on age-related effects of these psychotropic medications in patients who have been treated previously with MPH or FLX (ePOD-Pharmo) is also ongoing. The effects of psychotropic drugs on the developing brain are studied using neuroimaging techniques together with neuropsychological and psychiatric assessments of cognition, behavior and emotion. All assessments take place before, during (only in case of MPH) and after chronic treatment. DISCUSSION: The combined results of these approaches will provide new insight into the modulating effect of MPH and FLX on brain development.