An inventory of European data sources for the long-term safety evaluation of methylphenidate

An inventory of European data sources to support pharmacoepidemiologic research on neurodevelopmental outcomes in children following medication exposure in pregnancy: A contribution from the ConcePTION project

BACKGROUND

Studies on medication safety in pregnancy are increasingly focusing on child neurodevelopmental outcomes. Establishing neurodevelopmental safety is complex due to the range of neurodevelopmental outcomes and the length of follow-up needed for accurate assessment. The aim of this study was to provide an inventory of European data sources for use in pharmacoepidemiologic studies investigating neurodevelopment following maternal medication exposure.

METHOD

The EUROmediSAFE inventory of data sources in Europe for evaluating perinatal and long-term childhood risks associated with in-utero exposure to medication was updated by contacting colleagues across 31 European countries, literature review and internet searches. Included data sources must record at least one neurodevelopmental outcome and maternal medication use in pregnancy must be available, either in the data source itself or through linkage with another data source. Information on the domain of neurodevelopment, measure/scale used and the approach to measurement were recorded for each data source.

RESULTS

Ninety data sources were identified across 14 countries. The majority (63.3%) were created for health surveillance and research with the remaining serving administrative purposes (21.1% healthcare databases,15.6% other administrative databases). Five domains of neurodevelopment were identified-infant development (36 data sources,13 countries), child behaviour (27 data sources, 10 countries), cognition (29 data sources, 12 countries), educational achievement (20 data sources, 7 countries), and diagnostic codes for neurodevelopmental disorders (42 data sources, 11 countries). Thirty-nine data sources, in 12 countries, had information on more than one domain of neurodevelopment.

CONCLUSION

This inventory is invaluable to future studies planning to investigate the neurodevelopmental impact of medication exposures during pregnancy. Caution must be used when combining varied approaches to neurodevelopment outcome measurement, the age of children in the data source, and the sensitivity and specificity of the outcome measure selected should be borne in mind.

Use of the French national health insurance information system for research in the field of mental health: Systematic review and perspectives

PURPOSE

This systematic review registered in PROSPERO (CRD42021225296) aimed to describe the use of the French national health insurance information system, which covers the entire French population (67 million inhabitants), for research in the field of mental health.

METHODS

Three electronic databases and a journal hand-search identified 15 265 articles from January 1, 2003 (year of creation of the database) to October 31, 2020. Studies of any design were eligible for inclusion provided that they (i) made use of at least one component of the French health insurance database and (ii) focused on a topic in near and far connection with the field of mental health in France. Database used, design and methods, study period, population, key findings, and type of use for medical research were described.

RESULTS

A total of 152 studies were included in the review analysis. There was an increase in the number of published articles over time throughout the studied period. Studies focusing on adults (n = 139) largely outnumbered those focusing on children and adolescents (n = 11). Pharmacoepidemiological studies were by far the most frequent (n = 123), followed by methodological studies (n = 23), epidemiological studies (n = 17), and health economics studies (n = 3). The most studied psychotropic drugs were antidepressants (n = 27), anxiolytics (n = 27), and opioids (n = 25) while fewer studies focused on methylphenidate (n = 6) and on mood stabilizers (n = 5). Few studies specifically focused on psychiatric disorders, mainly depression (n = 4), suicide (n = 4), and psychotic disorders (n = 3).

CONCLUSION

This systematic review highlighted a relatively poor exploitation of the Système national des données de santé database in the field of psychiatric research with regard to the great possibilities it offers, with a clear lag in certain fields such as epidemiological or health economics studies and in specific populations, in particular children and adolescents.

Prediction of treatment dosage and duration from free-text prescriptions: an application to ADHD medications in the Swedish prescribed drug register

BACKGROUND

Accurate estimation of daily dosage and duration of medication use is essential to pharmacoepidemiological studies using electronic healthcare databases. However, such information is not directly available in many prescription databases, including the Swedish Prescribed Drug Register.

OBJECTIVE

To develop and validate an algorithm for predicting prescribed daily dosage and treatment duration from free-text prescriptions, and apply the algorithm to ADHD medication prescriptions.

METHODS

We developed an algorithm to predict daily dosage from free-text prescriptions using 8000 ADHD medication prescriptions as the training sample, and estimated treatment periods while taking into account several features including titration, stockpiling and non-perfect adherence. The algorithm was implemented to all ADHD medication prescriptions from the Swedish Prescribed Drug Register in 2013. A validation sample of 1000 ADHD medication prescriptions, independent of the training sample, was used to assess the accuracy for predicted daily dosage.

FINDINGS

In the validation sample, the overall accuracy for predicting daily dosage was 96.8%. Specifically, the natural language processing model (NLP1 and NLP2) have an accuracy of 99.2% and 96.3%, respectively. In an application to ADHD medication prescriptions in 2013, young adult ADHD medication users had the highest probability of discontinuing treatments as compared with other age groups. The daily dose of methylphenidate use increased with age substantially.

CONCLUSIONS

The algorithm provides a flexible approach to estimate prescribed daily dosage and treatment duration from free-text prescriptions using register data. The algorithm showed a good performance for predicting daily dosage in external validation.

CLINICAL IMPLICATIONS

The structured output of the algorithm could serve as basis for future pharmacoepidemiological studies evaluating utilization, effectiveness, and safety of medication use, which would facilitate evidence-based treatment decision-making.

Childhood methylphenidate adherence as a predictor of antidepressants use during adolescence

Methylphenidate (MPH) is a common and effective treatment for attention deficit hyperactivity disorder (ADHD), but little is known about the relationship between early childhood intake of MPH and onset of antidepressant treatment during adolescence. The study aimed to examine whether adherence to MPH during early childhood predicts the initiation of antidepressants during adolescence. This is a 12-year historical prospective nationwide cohort study of children enrolled in an integrated care system who were first prescribed MPH between the ages of 6 and 8 years (N = 6830). We tested for an association between their adherence to MPH during early childhood (as indicated by medication possession ratio from MPH onset through the age of twelve) and the likelihood of being prescribed any antidepressant during adolescence (age 13-18). As all country citizens are covered by mandatory health insurance, and full services are provided by one of the four integrated care systems, data regarding patients' diagnoses, prescriptions, and medical purchases are well documented. Logistic regression analysis indicated that those with higher adherence to MPH had a 50% higher risk (95% CI 1.16-1.93) of receiving antidepressants during adolescence when controlling for other comorbid psychiatric conditions and parental use of antidepressants. In this large-scale longitudinal study, MPH adherence during early childhood emerged as a predictor for antidepressant treatment during adolescence, which may reflect increased emotional and behavioral dysregulation in this group. The highly adherent patients are at higher risk and should be clinically monitored more closely, particularly into adolescence.

Risks and Benefits of Attention-Deficit/Hyperactivity Disorder Medication on Behavioral and Neuropsychiatric Outcomes: A Qualitative Review of Pharmacoepidemiology Studies Using Linked Prescription Databases

Attention-deficit/hyperactivity disorder (ADHD) medication is one of the most commonly prescribed medication classes in child and adolescent psychiatry, and its use is increasing rapidly in adult psychiatry. However, major questions and concerns remain regarding the benefits and risks of ADHD medication, especially in real-world settings. We conducted a qualitative systematic review of studies that investigated the effects of ADHD medication on behavioral and neuropsychiatric outcomes using linked prescription databases from the last 10 years and identified 40 studies from Europe, North America, and Asia. Among them, 18 used within-individual designs to account for confounding by indication. These studies suggested short-term beneficial effects of ADHD medication on several behavioral or neuropsychiatric outcomes (i.e., injuries, motor vehicle accidents, education, substance use disorder), with estimates suggesting relative risk reduction of 9% to 58% for these outcomes. The within-individual studies found no evidence of increased risks for suicidality and seizures. Replication studies are needed for several other important outcomes (i.e., criminality, depression, mania, psychosis). The available evidence from pharmacoepidemiology studies on long-term effects of ADHD medication was less clear. We discuss time-varying confounding and other limitations that should be considered when interpreting results from pharmacoepidemiology studies. Furthermore, we highlight several knowledge gaps to be addressed in future research and implications for research on mechanisms of outcomes of ADHD medications.

Cognitive Neuroscience of Attention Deficit Hyperactivity Disorder (ADHD) and Its Clinical Translation

This review focuses on the cognitive neuroscience of Attention Deficit Hyperactivity Disorder (ADHD) based on functional magnetic resonance imaging (fMRI) studies and on recent clinically relevant applications such as fMRI-based diagnostic classification or neuromodulation therapies targeting fMRI deficits with neurofeedback (NF) or brain stimulation. Meta-analyses of fMRI studies of executive functions (EFs) show that ADHD patients have cognitive-domain dissociated complex multisystem impairments in several right and left hemispheric dorsal, ventral and medial fronto-cingulo-striato-thalamic and fronto-parieto-cerebellar networks that mediate cognitive control, attention, timing and working memory (WM). There is furthermore emerging evidence for abnormalities in orbital and ventromedial prefrontal and limbic areas that mediate motivation and emotion control. In addition, poor deactivation of the default mode network (DMN) suggests an abnormal interrelationship between hypo-engaged task-positive and poorly "switched off" hyper-engaged task-negative networks, both of which are related to impaired cognition. Translational cognitive neuroscience in ADHD is still in its infancy. Pattern recognition analyses have attempted to provide diagnostic classification of ADHD using fMRI data with respectable classification accuracies of over 80%. Necessary replication studies, however, are still outstanding. Brain stimulation has been tested in heterogeneously designed, small numbered proof of concept studies targeting key frontal functional impairments in ADHD. Transcranial direct current stimulation (tDCS) appears to be promising to improve ADHD symptoms and cognitive functions based on some studies, but larger clinical trials of repeated stimulation with and without cognitive training are needed to test clinical efficacy and potential costs on non-targeted functions. Only three studies have piloted NF of fMRI-based frontal dysfunctions in ADHD using fMRI or near-infrared spectroscopy, with the two larger ones finding some improvements in cognition and symptoms, which, however, were not superior to the active control conditions, suggesting potential placebo effects. Neurotherapeutics seems attractive for ADHD due to their safety and potential longer-term neuroplastic effects, which drugs cannot offer. However, they need to be thoroughly tested for short- and longer-term clinical and cognitive efficacy and their potential for individualized treatment.

Editorial: The continuing contributions of multimodal treatment of attention over nearly two decades to initial attention-deficit hyperactivity disorder pharmacotherapy and long-term clinical course

The initial results of the Multimodal Treatment of Attention Deficit Hyperactivity Disorder (MTA) trial had profound effects on the way that Attention-Deficit Hyperactivity Disorder (ADHD) is managed clinically. Children from the original MTA cohort as well as a control group have been followed longitudinally for well over a decade and are beginning to provide important data regarding the long-term clinical course, treatment and consequences of ADHD into adulthood. Two articles in this issue of JCPP highlight important contributions from the MTA cohort. Swanson et al. highlights the potential long-term effects of stimulants on height whereas Sibley et al. highlights the importance of using multiple informants in assessing adulthood ADHD symptoms similar to children and suggest that current DSM criteria for ADHD may be overly stringent.

Methylphenidate dose optimization for ADHD treatment: review of safety, efficacy, and clinical necessity

Attention-deficit/hyperactivity disorder (ADHD) is a chronic psychiatric disorder characterized by hyperactivity and/or inattention and is often associated with a substantial impact on psychosocial functioning. Methylphenidate (MPH), a central nervous system stimulant, is commonly used for pharmacological treatment of adults and children with ADHD. Current practice guidelines recommend optimizing MPH dosage to individual patient needs; however, the clinical benefits of individual dose optimization compared with fixed-dose regimens remain unclear. Here we review the available literature on MPH dose optimization from clinical trials and real-world experience on ADHD management. In addition, we report safety and efficacy data from the largest MPH modified-release long-acting Phase III clinical trial conducted to examine benefits of dose optimization in adults with ADHD. Overall, MPH is an effective ADHD treatment with a good safety profile; data suggest that dose optimization may enhance the safety and efficacy of treatment. Further research is required to establish the extent to which short-term clinical benefits of MPH dose optimization translate into improved long-term outcomes for patients with ADHD.

Reports of Perceived Adverse Events of Stimulant Medication on Cognition, Motivation, and Mood: Qualitative Investigation and the Generation of Items for the Medication and Cognition Rating Scale

OBJECTIVE

There is no questionnaire to specifically monitor perceived adverse events of methylphenidate (MPH) on cognition, motivation, and mood. The current study therefore had two goals. First, to harvest accounts of such putative events from transcripts of interviews in samples enriched for such potential experiences. Second, to use the derived data to generate items for a new questionnaire that can be used for monitoring such events in medication trials or routine clinical care.

METHODS

Following a literature search aimed at identifying associations between MPH and cognition and/or motivation, a qualitative semistructured interview was designed to focus specifically on the domains of cognition (i.e., reasoning, depth/breadth of thinking, intellectual capacity, and creativity) and motivation (i.e., drive, effort, and attitudes toward rewards/incentives). Interviews were conducted with 45 participants drawn from the following four groups: (a) clinicians, child and adolescent psychiatrists, and pediatricians specializing in attention-deficit/hyperactivity disorder (ADHD) (n = 15); (2) teachers, with experience of teaching at least 10 medicated children with ADHD (n = 10); (3) parents of children with ADHD (n = 8) treated with MPH; and (4) adolescents/adults with ADHD (n = 12). Purposeful sampling was used to selectively recruit ADHD participants whose histories suggested a degree of vulnerability to MPH adverse events. Data were analyzed using a deductive approach to content analysis.

RESULTS

While we probed purposefully for cognitive and motivational adverse events, a third domain, related to mood, emerged from the reports. Therefore, three domains, each with a number of subdomains, were identified from the interview accounts: (i) Cognition (six subdomains; attention/concentration, changes in thinking, reduced creativity, sensory overload, memory, slower processing speed); (ii) motivation (four subdomains; loss of intrinsic motivation for goal-directed activities, external locus of control, lack of effort/engagement in daily tasks, increased focus on incentives); and (iii) mood (three subdomains; dampening of spontaneity/flat affect, mood dysregulation, increased anxiety/edginess). On the basis of these reports, 34 items were specified and incorporated into a prototype questionnaire, which was piloted and refined on the basis of field-testing.

CONCLUSIONS

Items were identified that capture potential/perceived cognitive, motivational, and mood-related adverse events of MPH. The items generated will allow us to further develop and psychometrically examine their prevalence, and the extent to which they are associated with medication adherence, treatment outcome, impairment, and other reported adverse events (e.g., loss of appetite/cardiovascular effects).

Pharmacoepidemiological safety studies in children: a systematic review

Purpose

In order to identify challenges in pediatric pharmacoepidemiological safety studies, we assessed the characteristics of such (published) studies.

Methods

Relevant articles from inception to 2013 were retrieved from Embase and Medline. We sequentially screened titles, abstracts and full texts with independent validation. We systematically collected data regarding general information, study methods and results.

Results

Out of 4825 unique articles, 268 full texts (5.6%) were retained; 147 (54.9%) pertained to drugs rather than vaccines. Considering the 268 studies, 202 (75.4%) concerned children and adolescents (2 to 11 years) and 14 (5.3%) included preterm newborns. Most studies originated from North America (154 [57.5%]) or Europe (92 [34.3%]). Only 47 studies (17.5%) were privately funded. The majority (174 [64.9%]) were cohort studies. Out of 268 studies, 196 (73.1%) collected data retrospectively; paper medical charts were the most common data source for the exposures (85 [31.7%]) and outcomes (122 [45.5%]). Only 3 (2.0%) drug‐only studies investigated rarely used drugs. Considering all 268 studies, only 27 (10.1%) reported sample size or power calculation. Most (75 [51.0%]) drug‐only studies corrected confounding by multivariate modeling unlike stratification in 66 (55.9%) vaccine‐only studies. Considering 75 child‐only studies without any statistically significant result, 41 (54.7%) did not discuss lack of power.

Conclusions

Although the field of pediatric pharmacoepidemiology is steadily developing evaluation seldom includes neonates, is mainly focused on few drug classes and safety outcomes and concerns mainly drug use in developed countries. Small study size is a specific challenge in pediatrics. Reporting should be improved. © 2016 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.

Unmet needs in paediatric psychopharmacology: Present scenario and future perspectives

Paediatric psychopharmacology holds great promise in two equally important areas of enormous biomedical and social impact, namely the treatment of behavioural abnormalities in children and adolescents, and the prevention of psychiatric disorders with adolescent- or adult-onset. Yet, in striking contrast, pharmacological treatment options presently available in child and adolescent psychiatry are dramatically limited. The most important currently unmet needs in paediatric psychopharmacology are: the frequent off-label prescription of medications to children and adolescents based exclusively on data from randomized controlled studies involving adult patients; the frequent lack of age-specific dose, long-term efficacy and tolerability/safety data; the lack of effective medications for many paediatric psychiatric disorders, most critically autism spectrum disorder; the scarcity and limitations of randomized placebo-controlled trials in paediatric psychopharmacology; the unexplored potential for the prevention of psychiatric disorders with adolescent- and adult-onset; the current lack of biomarkers to predict treatment response and severe adverse effects; the need for better preclinical data to foster the successful development of novel drug therapies; and the effective dissemination of evidence-based treatments to the general public, to better inform patients and families of the benefits and risks of pharmacological interventions during development. Priorities and strategies are proposed to overcome some of these limitations, including the European Child and Adolescent Clinical Psychopharmacology Network, as an overarching Pan-European infrastructure aimed at reliably carrying out much needed psychopharmacological trials in children and adolescents, in order to fill the identified gaps and improve overall outcomes.

The use of stimulant medications for non-core aspects of ADHD and in other disorders

Psychostimulants play a central role in the management of ADHD. Here we review the evidence pertaining to the use of methylphenidate, dexamphetamine and related amphetamine salts, the prodrug lisdexamfetamine and modafinil for the management of comorbid ADHD and non-ADHD indications. There is a growing consensus that stimulant medications are helpful at improving the emotional dysregulation and lability, and oppositional and conduct symptoms that are often associated with ADHD. There is some evidence that psychostimulants may improve outcomes in those with treatment resistant depression, reduce negative symptoms and improve cognitive performance in schizophrenia, and that methylphenidate may reduce binge eating in those with bulimia nervosa. In general medicine, whilst the evidence is at times contradictory, psychostimulants have been shown in some studies to be effective treatments for chronic fatigue and narcolepsy, and to improve outcomes post stroke, post head injury, in dementia and various cancers. It seems likely that these effects often result from a combination of, reduction in fatigue, improvements in concentration and cognitive functioning and a lifting of mood which may be a direct or indirect consequence of the medication. Further studies seem warranted and these should focus on efficacy, effectiveness and long term safety. This article is part of the Special Issue entitled 'CNS Stimulants'.