Use of ADHD drugs in the Nordic countries: a population-based comparison study

Variation in attitudes toward diagnosis and medication of ADHD: a survey among clinicians in the Norwegian child and adolescent mental health services

Prevalence and medication rates of ADHD vary geographically, both between and within countries. No absolute cutoff exists between ADHD and normal behavior, making clinician attitudes (leading to local practice cultures) a potential explanation for the observed variation in diagnosis and medication rates. The objective of this study was to describe variation in attitudes toward diagnosis and medication of ADHD among clinicians working in child and adolescent mental health services (CAMHS). We hypothesized that attitudes would vary along a spectrum from "restrictive" to "liberal". We also explored whether differences in attitudes between clinicians were related to professional background and workplace (clinic). A survey in the form of a web-based questionnaire was developed. All CAMHS outpatient clinics in Norway were invited. Potential respondents were all clinicians involved in diagnosing and treating children and adolescents with ADHD. To investigate the existence of attitudes toward diagnosis and medication as latent constructs, we applied confirmatory factor analysis (CFA). We further examined how much of variance in attitudes could be ascribed to profession and clinics by estimating intraclass correlation coefficients. In total, 674 respondents representing 77 (88%) of the clinics participated. We confirmed variation in attitudes with average responses leaning toward the "restrictive" end of the spectrum. CFA supported "attitude toward diagnosis" and "attitude toward medication" as separate, and moderately correlated (r = 0.4) latent variables, representing a scale from restrictive to liberal. Professional background and workplace explained only a small part of variance in these attitudes.

Trends in use of attention deficit hyperactivity disorder medication among children and adolescents in Scandinavia in 2010-2020

The objective of the study was to compare the use of attention deficit hyperactivity disorder (ADHD) medication among children and adolescents in Scandinavia 2010-2020. Using aggregated prescription data for individuals aged 5-19 years, we calculated annual prevalence proportions of ADHD medication (users/1000 inhabitants) for each country, overall and stratified by age and sex. Overall, use of ADHD medication increased during 2010-2020 in all countries. The increase was pronounced in Sweden reaching 35 users/1000 inhabitants in 2020 (119% increase), whereas it reached 22/1000 in Denmark and Norway (equivalent to a 38% and 16% increase, respectively). Methylphenidate was the most frequently used drug and Sweden had the highest use reaching 25/1000 in 2020 compared to 16/1000 and 18/1000 in Denmark and Norway, respectively. Lisdexamfetamine use increased steadily and was also highest in Sweden (13/1000 in 2020). In 2020, atomoxetine use was higher in Sweden (4.6/1000) and Denmark (4.5/1000) compared to Norway (2.2/1000). From 2015, use of guanfacine increased in Sweden reaching 4.4/1000 in 2020 but remained low in Denmark (0.4/1000) and Norway (0.7/1000). Use of dexamphetamine was low (ranging from 0.47 to 0.75/1000 in 2020) in the three countries. ADHD medication use was highest in Sweden across all age groups. In all countries, the prevalence was higher in males compared to females. In conclusion, use of ADHD medication among children and adolescents in Scandinavia is increasing. The prevalence of use is higher in Sweden for all drug groups compared to Norway and Denmark.

Methylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children and adolescents with ADHD find it difficult to pay attention and they are hyperactive and impulsive. Methylphenidate is the psychostimulant most often prescribed, but the evidence on benefits and harms is uncertain. This is an update of our comprehensive systematic review on benefits and harms published in 2015.

OBJECTIVES

To assess the beneficial and harmful effects of methylphenidate for children and adolescents with ADHD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases and two trials registers up to March 2022. In addition, we checked reference lists and requested published and unpublished data from manufacturers of methylphenidate.

SELECTION CRITERIA

We included all randomised clinical trials (RCTs) comparing methylphenidate versus placebo or no intervention in children and adolescents aged 18 years and younger with a diagnosis of ADHD. The search was not limited by publication year or language, but trial inclusion required that 75% or more of participants had a normal intellectual quotient (IQ > 70). We assessed two primary outcomes, ADHD symptoms and serious adverse events, and three secondary outcomes, adverse events considered non-serious, general behaviour, and quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and risk of bias assessment for each trial. Six review authors including two review authors from the original publication participated in the update in 2022. We used standard Cochrane methodological procedures. Data from parallel-group trials and first-period data from cross-over trials formed the basis of our primary analyses. We undertook separate analyses using end-of-last period data from cross-over trials. We used Trial Sequential Analyses (TSA) to control for type I (5%) and type II (20%) errors, and we assessed and downgraded evidence according to the GRADE approach.

MAIN RESULTS

We included 212 trials (16,302 participants randomised); 55 parallel-group trials (8104 participants randomised), and 156 cross-over trials (8033 participants randomised) as well as one trial with a parallel phase (114 participants randomised) and a cross-over phase (165 participants randomised). The mean age of participants was 9.8 years ranging from 3 to 18 years (two trials from 3 to 21 years). The male-female ratio was 3:1. Most trials were carried out in high-income countries, and 86/212 included trials (41%) were funded or partly funded by the pharmaceutical industry. Methylphenidate treatment duration ranged from 1 to 425 days, with a mean duration of 28.8 days. Trials compared methylphenidate with placebo (200 trials) and with no intervention (12 trials). Only 165/212 trials included usable data on one or more outcomes from 14,271 participants. Of the 212 trials, we assessed 191 at high risk of bias and 21 at low risk of bias. If, however, deblinding of methylphenidate due to typical adverse events is considered, then all 212 trials were at high risk of bias.

PRIMARY OUTCOMES

methylphenidate versus placebo or no intervention may improve teacher-rated ADHD symptoms (standardised mean difference (SMD) -0.74, 95% confidence interval (CI) -0.88 to -0.61; I² = 38%; 21 trials; 1728 participants; very low-certainty evidence). This corresponds to a mean difference (MD) of -10.58 (95% CI -12.58 to -8.72) on the ADHD Rating Scale (ADHD-RS; range 0 to 72 points). The minimal clinically relevant difference is considered to be a change of 6.6 points on the ADHD-RS. Methylphenidate may not affect serious adverse events (risk ratio (RR) 0.80, 95% CI 0.39 to 1.67; I² = 0%; 26 trials, 3673 participants; very low-certainty evidence). The TSA-adjusted intervention effect was RR 0.91 (CI 0.31 to 2.68).

SECONDARY OUTCOMES

methylphenidate may cause more adverse events considered non-serious versus placebo or no intervention (RR 1.23, 95% CI 1.11 to 1.37; I² = 72%; 35 trials 5342 participants; very low-certainty evidence). The TSA-adjusted intervention effect was RR 1.22 (CI 1.08 to 1.43). Methylphenidate may improve teacher-rated general behaviour versus placebo (SMD -0.62, 95% CI -0.91 to -0.33; I² = 68%; 7 trials 792 participants; very low-certainty evidence), but may not affect quality of life (SMD 0.40, 95% CI -0.03 to 0.83; I² = 81%; 4 trials, 608 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

The majority of our conclusions from the 2015 version of this review still apply. Our updated meta-analyses suggest that methylphenidate versus placebo or no-intervention may improve teacher-rated ADHD symptoms and general behaviour in children and adolescents with ADHD. There may be no effects on serious adverse events and quality of life. Methylphenidate may be associated with an increased risk of adverse events considered non-serious, such as sleep problems and decreased appetite. However, the certainty of the evidence for all outcomes is very low and therefore the true magnitude of effects remain unclear. Due to the frequency of non-serious adverse events associated with methylphenidate, the blinding of participants and outcome assessors is particularly challenging. To accommodate this challenge, an active placebo should be sought and utilised. It may be difficult to find such a drug, but identifying a substance that could mimic the easily recognised adverse effects of methylphenidate would avert the unblinding that detrimentally affects current randomised trials. Future systematic reviews should investigate the subgroups of patients with ADHD that may benefit most and least from methylphenidate. This could be done with individual participant data to investigate predictors and modifiers like age, comorbidity, and ADHD subtypes.

[Increasing methylphenidate abuse: Tracking and profiles during 13-years]

BACKGROUND

Methylphenidate is indicated for attention deficit hyperactivity disorder (ADHD). Several studies have evaluated its abuse in specific populations (students, drug users) and few in the general population. This work describes the extent of its abuse in a region of more than 5 million inhabitants.

METHOD

Based on regional health insurance data from 2005 to 2017, the clustering method identifies different methylphenidate use profiles according to several characteristics (number of different prescribers and pharmacies, number of dispensations, number of defined daily dose dispensed). The groups characterised by high values of these variables will be qualified as "deviant".

RESULTS

In 13 years, the number of patients with at least one dispensation in the first quarter has been multiplied by 5.8 times. The proportion of adults has increased (20% in 2017) and their number has been multiplied by 10. Five groups are identified, three of them are characterised by "deviant" behaviour. Group 5 (n=11, 0.04%) has higher values than 4 (n=112, 0.4%) and 3 (n=407, 1.6%). These patients are older and more frequently use benzodiazepines and opiate substitution drugs. Groups 1 (n=13,132, 51%) and 2 (n=11,941, 46.7%) are more likely to be taken up by young subjects. The number of subjects with "deviant" behaviour increased until 2011 and after a decrease, the highest number of subjects concerned has been observed since 2015.

CONCLUSION

In view of the increase of subjects with "deviant" behaviour, it is necessary to make the medical community and patients aware on the risk of abuse of methylphenidate. The recent extension of the indication for ADHD in adults and the broadening of the conditions of prescription require increased vigilance.

Focus on your locus with a massively parallel reporter assay

A growing number of variants associated with risk for neurodevelopmental disorders have been identified by genome-wide association and whole genome sequencing studies. As common risk variants often fall within large haplotype blocks covering long stretches of the noncoding genome, the causal variants within an associated locus are often unknown. Similarly, the effect of rare noncoding risk variants identified by whole genome sequencing on molecular traits is seldom known without functional assays. A massively parallel reporter assay (MPRA) is an assay that can functionally validate thousands of regulatory elements simultaneously using high-throughput sequencing and barcode technology. MPRA has been adapted to various experimental designs that measure gene regulatory effects of genetic variants within cis- and trans-regulatory elements as well as posttranscriptional processes. This review discusses different MPRA designs that have been or could be used in the future to experimentally validate genetic variants associated with neurodevelopmental disorders. Though MPRA has limitations such as it does not model genomic context, this assay can help narrow down the underlying genetic causes of neurodevelopmental disorders by screening thousands of sequences in one experiment. We conclude by describing future directions of this technique such as applications of MPRA for gene-by-environment interactions and pharmacogenetics.

Adults referred to a national ADHD clinic in Iceland: clinical characteristics and follow-up status

OBJECTIVE

Evaluate adults referred to a national ADHD clinic, by comparing those diagnosed with those who were not, and those who screened negative and to evaluate changes among those diagnosed at follow-up.

METHOD

Data obtained from 531 patients' medical records (49.7% males). One hundred thirty-six screened negative, 395 positive and 305 met diagnostic criteria for ADHD. Eighty-three of them were contacted by phone at follow-up.

RESULTS

ADHD diagnosis was associated with lower educational status and more concerns expressed by parents and teachers during childhood. Participants not diagnosed with ADHD more often met diagnostic criteria for dysthymia, agoraphobia and generalized anxiety, and were more likely to be diagnosed with two or more comorbid disorders. At follow-up, all reported a significant reduction of ADHD symptoms, irrespective of medication, but the medicated participants reported fewer symptoms of inattention and better functioning in daily life.

CONCLUSION

Adults referred to ADHD clinics may have multiple mental health problems, regardless of whether they receive ADHD diagnosis or not. This could have implications for differential diagnoses of ADHD in adults and emphasises the need to have appropriate treatment available for both groups. Psychoeducation about ADHD may be very helpful in decreasing anxiety and ADHD symptoms.

Causal modelling of variation in clinical practice and long-term outcomes of ADHD using Norwegian registry data: the ADHD controversy project

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is among the most common mental disorders in children and adolescents, and it is a strong risk factor for several adverse psychosocial outcomes over the lifespan. There are large between-country and within-country variations in diagnosis and medication rates. Due to ethical and practical considerations, a few studies have examined the effects of receiving a diagnosis, and there is a lack of research on effects of medication on long-term outcomes.Our project has four aims organised in four work packages: (WP1) To examine the prognosis of ADHD (with and without medication) compared with patients with other psychiatric diagnoses, patients in contact with public sector child and adolescent psychiatric outpatient clinics (without diagnosis) and the general population; (WP2) Examine within-country variation in ADHD diagnoses and medication rates by clinics' catchment area; and(WP3) Identify causal effects of being diagnosed with ADHD and (WP4) ADHD medication on long-term outcomes.

METHOD AND ANALYSIS

Our project links several nationwide Norwegian registries. The patient sample is all persons aged 5-18 years that were in contact with public sector child and adolescent psychiatric outpatient clinics in 2009-2011. Our comparative analysis of prognosis will be based on survival analysis and mixed-effects models. Our analysis of variation will apply mixed-effects models and generalised linear models. We have two identification strategies for the effect of being diagnosed with ADHD and of receiving medication on long-term outcomes. Both strategies rely on using preference-based instrumental variables, which in our project are based on provider preferences for ADHD diagnosis and medication.

ETHICS AND DISSEMINATION

The project is approved by the Regional Ethics Committee, Norway (REC number 2017/2150/REC south-east D). All papers will be published in open-access journals and results will be presented in national and international conferences.

TRIAL REGISTRATION NUMBERS

ISRCTN11573246 and ISRCTN11891971.

The female side of pharmacotherapy for ADHD-A systematic literature review

OBJECTIVE

This comprehensive review examined sex differences in prescription rates and efficacy or effectiveness of pharmacotherapy treatment in girls and women with attention deficit hyperactivity disorder (ADHD), while identifying gaps in the scientific knowledge on this topic.

METHOD

A rigorous electronic database search was carried out in order to identify all published studies on female-specific effects of stimulants and non-stimulants in the treatment of ADHD. In total, 2672 studies were screened of which 21 studies (seven on prescription rates, 14 on effects of pharmacotherapy) met the inclusion criteria and were included for analysis.

RESULTS

In all seven studies on ADHD prescription rates, girls received significantly less prescriptions than boys, a difference however no longer seen in adults with the exception of one study. Each of the 14 studies on effectiveness / efficacy found at least one sex-difference in the effects of ADHD pharmacotherapy.

CONCLUSION

Several sex-differences are demonstrated in the prescription, usage and efficacy /effectiveness of both stimulant and non-stimulant ADHD pharmacotherapy. A single daily use of MPH may possibly not be optimal for girls with ADHD and ATX may be a promising medication for girls and women with ADHD. The robustness of this result requires further investigation.

Prescription Stimulant Misuse and ADHD Symptomatology Among College Students in Iceland

Objective: Misuse of prescription stimulant medication is a prevalent problem on American college campuses; however, few studies have been conducted beyond the United States. Although Iceland has the highest methylphenidate prescription rates in the world, prevalence of stimulant misuse within the Icelandic college student population remains to be investigated. Method: We examined the prevalence of prescription stimulant misuse among N = 521 college students in Iceland, using an online survey. Results: Overall prevalence of lifetime stimulant misuse was approximately 13%; 11% among participants without a prescription for stimulant medication, and 42% among participants holding a prescription. The primary reported reason for misuse was academic enhancement; risk factors included male sex, anxiety symptoms, and ADHD symptomatology. Conclusion: The present findings have implications for public health policy in Iceland, particularly as it relates to the college population. Prevention and intervention programs that provide college students with safer strategies to manage academic demands are warranted.

Cognitive enhancement with licit and illicit stimulants in the Netherlands and Finland: what is the evidence?

Purpose

European studies have shown lower prevalence rates of prescription stimulant use for cognitive enhancement, especially among student populations, compared to North America. This difference requires more cross-country research of the various factors involved. To find out whether other parts of the globe are witnessing similar increases in extra-medical stimulant use, and how this might relate to cognitive enhancement, requires empirical study of local contexts. This paper aims to argue that the academic and public discussion on cognitive enhancement should consider the specific country context of drug policy and research and rethink which drugs are included under the term cognitive enhancement drugs.

Design/methodology/approach

This paper offers a general review and a sociological country comparison between the Netherlands and Finland, focusing not only on prescription stimulants used to treat attention deficit hyperactivity disorder but also illicit amphetamines among young adults and methylphenidate use among Dutch and Finnish participants of the Global Drug Survey. This paper emphasises sociocultural perspectives and the importance of context in cognitive enhancement in general as the line between therapeutic and enhancement use can often be blurred. Data is drawn from global, European and national sources, including the International Narcotics Control Board, European Monitoring Centre for Drugs and Drug Addiction and Global Drug Survey.

Findings

There are hardly any national empirical studies done on cognitive enhancement drug use in Finland. On the other hand, there have been studies in the Netherlands showcasing that the use of prescription stimulants and other drugs for enhancement purposes is something that is happening among young people, albeit yet in a relatively small scale. Illicit and licit stimulant use and drug policy action in relation to cognitive enhancement drugs in the two countries varies, emphasising the importance of country context.

Originality/value

Given that cross-country research is scarce, this general review provides one of the first glimpses into cognitive enhancement drug use by comparing the country context and research in Finland, where the phenomenon has not been studied, with the Netherlands, where the topic has received more research and public attention. Further research areas are suggested.

Replicating medication trend studies using ad hoc information extraction in a clinical data warehouse

Background

Medication trend studies show the changes of medication over the years and may be replicated using a clinical Data Warehouse (CDW). Even nowadays, a lot of the patient information, like medication data, in the EHR is stored in the format of free text. As the conventional approach of information extraction (IE) demands a high developmental effort, we used ad hoc IE instead. This technique queries information and extracts it on the fly from texts contained in the CDW.

Methods

We present a generalizable approach of ad hoc IE for pharmacotherapy (medications and their daily dosage) presented in hospital discharge letters. We added import and query features to the CDW system, like error tolerant queries to deal with misspellings and proximity search for the extraction of the daily dosage. During the data integration process in the CDW, negated, historical and non-patient context data are filtered. For the replication studies, we used a drug list grouped by ATC (Anatomical Therapeutic Chemical Classification System) codes as input for queries to the CDW.

Results

We achieve an F1 score of 0.983 (precision 0.997, recall 0.970) for extracting medication from discharge letters and an F1 score of 0.974 (precision 0.977, recall 0.972) for extracting the dosage. We replicated three published medical trend studies for hypertension, atrial fibrillation and chronic kidney disease. Overall, 93% of the main findings could be replicated, 68% of sub-findings, and 75% of all findings. One study could be completely replicated with all main and sub-findings.

Conclusion

A novel approach for ad hoc IE is presented. It is very suitable for basic medical texts like discharge letters and finding reports. Ad hoc IE is by definition more limited than conventional IE and does not claim to replace it, but it substantially exceeds the search capabilities of many CDWs and it is convenient to conduct replication studies fast and with high quality.

Methylphenidate for attention deficit hyperactivity disorder (ADHD) in children and adolescents - assessment of adverse events in non-randomised studies

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in childhood. The psychostimulant methylphenidate is the most frequently used medication to treat it. Several studies have investigated the benefits of methylphenidate, showing possible favourable effects on ADHD symptoms, but the true magnitude of the effect is unknown. Concerning adverse events associated with the treatment, our systematic review of randomised clinical trials (RCTs) demonstrated no increase in serious adverse events, but a high proportion of participants suffered a range of non-serious adverse events.

OBJECTIVES

To assess the adverse events associated with methylphenidate treatment for children and adolescents with ADHD in non-randomised studies.

SEARCH METHODS

In January 2016, we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 12 other databases and two trials registers. We also checked reference lists and contacted authors and pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included non-randomised study designs. These comprised comparative and non-comparative cohort studies, patient-control studies, patient reports/series and cross-sectional studies of methylphenidate administered at any dosage or formulation. We also included methylphenidate groups from RCTs assessing methylphenidate versus other interventions for ADHD as well as data from follow-up periods in RCTs. Participants had to have an ADHD diagnosis (from the 3rd to the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders or the 9th or 10th edition of theInternational Classification of Diseases, with or without comorbid diagnoses. We required that at least 75% of participants had a normal intellectual capacity (intelligence quotient of more than 70 points) and were aged below 20 years. We excluded studies that used another ADHD drug as a co-intervention.

DATA COLLECTION AND ANALYSIS

Fourteen review authors selected studies independently. Two review authors assessed risk of bias independently using the ROBINS-I tool for assessing risk of bias in non-randomised studies of interventions. All review authors extracted data. We defined serious adverse events according to the International Committee of Harmonization as any lethal, life-threatening or life-changing event. We considered all other adverse events to be non-serious adverse events and conducted meta-analyses of data from comparative studies. We calculated meta-analytic estimates of prevalence from non-comparative cohorts studies and synthesised data from patient reports/series qualitatively. We investigated heterogeneity by conducting subgroup analyses, and we also conducted sensitivity analyses.

MAIN RESULTS

We included a total of 260 studies: 7 comparative cohort studies, 6 of which compared 968 patients who were exposed to methylphenidate to 166 controls, and 1 which assessed 1224 patients that were exposed or not exposed to methylphenidate during different time periods; 4 patient-control studies (53,192 exposed to methylphenidate and 19,906 controls); 177 non-comparative cohort studies (2,207,751 participants); 2 cross-sectional studies (96 participants) and 70 patient reports/series (206 participants). Participants' ages ranged from 3 years to 20 years. Risk of bias in the included comparative studies ranged from moderate to critical, with most studies showing critical risk of bias. We evaluated all non-comparative studies at critical risk of bias. The GRADE quality rating of the evidence was very low.Primary outcomesIn the comparative studies, methylphenidate increased the risk ratio (RR) of serious adverse events (RR 1.36, 95% confidence interval (CI) 1.17 to 1.57; 2 studies, 72,005 participants); any psychotic disorder (RR 1.36, 95% CI 1.17 to 1.57; 1 study, 71,771 participants); and arrhythmia (RR 1.61, 95% CI 1.48 to 1.74; 1 study, 1224 participants) compared to no intervention.In the non-comparative cohort studies, the proportion of participants on methylphenidate experiencing any serious adverse event was 1.20% (95% CI 0.70% to 2.00%; 50 studies, 162,422 participants). Withdrawal from methylphenidate due to any serious adverse events occurred in 1.20% (95% CI 0.60% to 2.30%; 7 studies, 1173 participants) and adverse events of unknown severity led to withdrawal in 7.30% of participants (95% CI 5.30% to 10.0%; 22 studies, 3708 participants).Secondary outcomesIn the comparative studies, methylphenidate, compared to no intervention, increased the RR of insomnia and sleep problems (RR 2.58, 95% CI 1.24 to 5.34; 3 studies, 425 participants) and decreased appetite (RR 15.06, 95% CI 2.12 to 106.83; 1 study, 335 participants).With non-comparative cohort studies, the proportion of participants on methylphenidate with any non-serious adverse events was 51.2% (95% CI 41.2% to 61.1%; 49 studies, 13,978 participants). These included difficulty falling asleep, 17.9% (95% CI 14.7% to 21.6%; 82 studies, 11,507 participants); headache, 14.4% (95% CI 11.3% to 18.3%; 90 studies, 13,469 participants); abdominal pain, 10.7% (95% CI 8.60% to 13.3%; 79 studies, 11,750 participants); and decreased appetite, 31.1% (95% CI 26.5% to 36.2%; 84 studies, 11,594 participants). Withdrawal of methylphenidate due to non-serious adverse events occurred in 6.20% (95% CI 4.80% to 7.90%; 37 studies, 7142 participants), and 16.2% were withdrawn for unknown reasons (95% CI 13.0% to 19.9%; 57 studies, 8340 participants).

AUTHORS' CONCLUSIONS

Our findings suggest that methylphenidate may be associated with a number of serious adverse events as well as a large number of non-serious adverse events in children and adolescents, which often lead to withdrawal of methylphenidate. Our certainty in the evidence is very low, and accordingly, it is not possible to accurately estimate the actual risk of adverse events. It might be higher than reported here.Given the possible association between methylphenidate and the adverse events identified, it may be important to identify people who are most susceptible to adverse events. To do this we must undertake large-scale, high-quality RCTs, along with studies aimed at identifying responders and non-responders.

Patterns and profiles of methylphenidate use both in children and adults

AIM

The aim of the present study was to characterize patterns of use of methylphenidate (MPH), a prescription stimulant medication recommended in the treatment of attention deficit hyperactivity disorder (ADHD) and of narcolepsy, in France, both in children and adults, over a 3-year period.

METHODS

Using the French General Health Insurance database, limited to two areas covering approximately 4 million individuals, we made up a cohort of incident MPH users between July 2010 and June 2013. Splitting them into distinct age groups (18-24, 25-49 and ≥50 years of age for adults and <6, 6-11 and 12-17 years of age for children), we established the characteristics of these populations at MPH initiation and during follow-up according to the duration of treatment, quantities dispensed and coprescription with central nervous system (CNS) drugs.

RESULTS

We included a cohort of 3534 incident users, involving 30 238 dispensings of MPH, leading to an annual rate of 29 incident users per 100 000 in 2013. Children (66% of new users) were characterized by long-term use of MPH with few comedications. The group of 25-49-year-old patients were dispensed MPH more frequently than other groups, had the highest mean dose and were more often coprescribed other CNS drugs. The ≥50 year-old group was more often coprescribed antidepressants and antiparkinsonian drugs.

CONCLUSIONS

Our pharmacoepidemiological study involving incident MPH users with a large number of characteristics showed different patterns of MPH use among children and adults. The results from the 25-49-year-old group suggested that MPH might be being used for medical conditions other than ADHD or narcolepsy in adults, and that it might be subject to misuse and/or abuse.

Patient and provider characteristics related with prescribing of ADHD medication: Nationwide health insurance claims database study in Korea

BACKGROUND

Little is known about the association between prescribing of attention deficit hyperactivity disorder (ADHD) medication and the patient's age, gender, and type of medical institution in Asia region.

INTRODUCTION

This study investigates the prevalence and factors of diagnosis and pharmacological treatment of ADHD in the pediatric population.

METHODS

Using the Korea Health Insurance database, study participants were identified as pediatric patients (≤17 years) with at least 1 diagnosis of ADHD (ICD-10, F90) from January 1, 2007 to December 31, 2011. The annual prevalence of ADHD diagnosis and medication was calculated. Annual differences in the prevalence between 2007 and 2011 with 95% confidence intervals (CIs) were estimated. We conducted multiple logistic regression analysis to estimate adjusted odds ratios (aORs) and their 95% CI to investigate predictors associated with prescribing of ADHD medication.

RESULTS

The prevalence of ADHD medication prescribing increased by 26.57% (95% CI, 26.27-26.88) from 0.53% in 2007 to 0.72% in 2011. The prevalence increased by 41.56% (95% CI, 40.51-42.65) in females compared with 34.91% (95% CI, 34.47-35.36) in males. Whereas the prevalence decreased in patients younger than 6 years old, it increased by 74.30% (95% CI, 72.84-75.79) in the 13 to 17-year group. Males were more likely than females to be treated with ADHD medication (aOR, 1.12; 95% CI, 1.10-1.13). Physician specialty (psychiatry vs non-psychiatry) (aOR, 1.37; 95% CI, 1.34-1.40) were associated with prescribing of ADHD medication.

CONCLUSION

Rapid increases in the diagnosis and pharmacological treatment of ADHD in the pediatric population have been observed. While demographic characteristics were similar to other countries, provider characteristics were different with others reporting that the majority of patients were treated by physicians specializing in psychiatry.

ADHD in children and young people: prevalence, care pathways, and service provision

Attention-deficit hyperactivity disorder (ADHD) is a common childhood behavioural disorder. Systematic reviews indicate that the community prevalence globally is between 2% and 7%, with an average of around 5%. At least a further 5% of children have substantial difficulties with overactivity, inattention, and impulsivity that are just under the threshold to meet full diagnostic criteria for ADHD. Estimates of the administrative prevalence (clinically diagnosed or recorded) vary worldwide, and have been increasing over time. However, ADHD is still relatively under-recognised and underdiagnosed in most countries, particularly in girls and older children. ADHD often persists into adulthood and is a risk factor for other mental health disorders and negative outcomes, including educational underachievement, difficulties with employment and relationships, and criminality. The timely recognition and treatment of children with ADHD-type difficulties provides an opportunity to improve long-term outcomes. This Review includes a systematic review of the community and administrative prevalence of ADHD in children and adolescents, an overview of barriers to accessing care, a description of associated costs, and a discussion of evidence-based pathways for the delivery of clinical care, including a focus on key issues for two specific age groups-younger children (aged ≤6 years) and adolescents requiring transition of care from child to adult services.

Prevalence, Patient Characteristics, and Pharmacological Treatment of Children, Adolescents, and Adults Diagnosed With ADHD in Sweden

OBJECTIVE

The objective of this study was to describe the epidemiology of diagnosed ADHD and the pharmacological treatment of patients with ADHD in Sweden. Specifically, this study estimates the prevalence of patients with a newly registered diagnosis of ADHD over a 5-year period, and the prevalence of all patients with a registered ADHD diagnoses over a 6-year period in Sweden.

METHOD

Two population-based registries were used as data sources for this study; the National Patient Register (NPR) and the Prescribed Drug Register (PDR). The international Classification of Diseases 10th Revison (ICD-10) was used to identify patients with ADHD.

RESULTS

The annual prevalence of ADHD in the general population of Sweden was found to be 1.1 per 1,000 persons in the year 2006 increasing to 4.8 per 1,000 persons in 2011. The corresponding prevalence for newly diagnosed patients increased from 0.6 per 1,000 persons in 2007 to 1.3 per 1,000 persons in 2011. The majority of diagnosed patients received pharmacological treatment, with methylphenidate being the most common dispensed drug. Comorbidities in the autism spectrum were most common for younger patients, while substance abuse, anxiety, and personality disorder were the most common comorbidities in older patients.

CONCLUSION

From 2006 to 2011, the number of patients diagnosed with ADHD has increased in Sweden over all ages. The majority of patients diagnosed with ADHD in Sweden received a pharmacological treatment regardless of age. An ADHD diagnosis was often accompanied with psychiatric comorbidity.

Estimated prevalence and incidence of diagnosed ADHD and health care utilization in adults in Sweden - a longitudinal population-based register study

BACKGROUND

Although the worldwide prevalence of attention-deficit/hyperactivity disorder (ADHD) in adults is estimated to be between 2% and 5%, it is considered to be underdiagnosed. This register study explored the prevalence of diagnosed ADHD and incidence of newly diagnosed ADHD in Swedish adults over time, and assessed comorbidities and pharmacologic treatment.

METHODS

National Patient Register data were used to estimate the overall prevalence of adults (≥18 years) with a registered ADHD diagnosis from 2006 to 2011, and the incidence of newly registered diagnoses from 2007 to 2011. Data from the Prescribed Drug Register were used to estimate the mean dose of the most frequently prescribed ADHD medication.

RESULTS

The estimated annual prevalence (N=44,364) of diagnosed ADHD increased from 0.58 per 1,000 persons in 2006 to 3.54 per 1,000 persons in 2011. The estimated annual incidence of newly diagnosed ADHD (N=24,921) increased from 0.39 per 1,000 persons to 0.90 per 1,000 persons between 2007 and 2011. At least one comorbidity was diagnosed in 52.6% of adults with ADHD (54.0% of newly diagnosed adults), with anxiety, substance use disorders, and depression being the most common. Among all adults with ADHD, 78.9% (65.7% of newly diagnosed adults) were prescribed ADHD medication and one-third were prescribed more than one add-on medication. Osmotic release oral system methylphenidate was the most commonly used medication. The mean daily dose was 51.5 mg, and was significantly higher in males, patients with substance use disorders, patients with drug holidays, and patients with at least one add-on medication. The most frequent concomitant medications were anxiolytics and hypnotics.

CONCLUSION

In Sweden, the number of adults diagnosed with ADHD increased between 2006 and 2011, and the majority of patients were prescribed ADHD-specific medication. Over one-half of patients had psychiatric comorbidities; one-third were prescribed more than one add-on medication. Consumption of pharmacologic ADHD medication was high in specific patient subpopulations.

Relative age within the school year and diagnosis of attention-deficit hyperactivity disorder: a nationwide population-based study

BACKGROUND

Findings are mixed on the relationship between attention-deficit hyperactivity disorder (ADHD) and younger relative age in the school year. We aimed to investigate whether relative age is associated with ADHD diagnosis in a country where prescribing rates are low and whether any such association has changed over time or relates to comorbid disorders (eg, conduct disorder [CD], oppositional defiant disorder [ODD], or learning disorder [LD]).

METHODS

We used nationwide population-based registers to identify all Finnish children born between Jan 1, 1991, and Dec 31, 2004, who were diagnosed with ADHD from age 7 years onwards (age of starting school). We calculated incidence ratios to assess the inter-relations between relative age within the school year, age at ADHD diagnosis, and year of diagnosis (1998-2003 vs 2004-11).

FINDINGS

Between Jan 1, 1998, and Dec 31, 2011, 6136 children with ADHD were identified. Compared with the oldest children in the school year (ie, those born between January and April), the cumulative incidence of an ADHD diagnosis was greatest for the youngest children (ie, those born between September and December); for boys the incidence ratio was 1·26 (95% CI 1·18-1·35; p<0·0001) and for girls it was 1·31 (1·12-1·54; p=0·0007). The association between relative age and age at ADHD diagnosis reflected children diagnosed before age 10 years, and the strength of this association increased during recent years (2004-11). Thus, compared with children born between January and April, for those born between May and August, the ADHD incidence ratio was 1·37 (95% CI 1·24-1·53; p<0·0001) and for those born between September and December, the incidence ratio was 1·64 (1·48-1·81; p<0·0001). The relative age effect was not accounted for by comorbid disorders such as CD, ODD, or LD.

INTERPRETATION

In a health service system with low prescribing rates for ADHD, a younger relative age is associated with an increased likelihood of receiving a clinical diagnosis of ADHD. This effect has increased in recent years. Teachers, parents, and clinicians should take relative age into account when considering the possibility of ADHD in a child or encountering a child with a pre-existing diagnosis.

FUNDING

Academy of Finland, Finnish Medical Foundation, Orion Pharma Foundation, Finnish Cultural Foundation.

Social selection in cohort studies and later representation of childhood psychiatric diagnoses: The Danish National Birth Cohort

Aim: This study aimed to estimate the relative representation of childhood psychiatric diagnoses and use of psychotropic medication in the Danish National Birth Cohort (DNBC) compared to the general population. Methods: The general population was identified as all childbirths in Denmark during 1998-2002 (N=344,160). Linking the DNBC (N=91,442) and the general population to the Danish national health registries, all children were followed until they received an ICD-10 psychiatric diagnosis, had a prescription of psychotropic medication or to the end of follow-up in 2013. The prevalence ratios (PRs) with corresponding 95% confidence intervals (CI) were estimated for each psychiatric diagnosis and by sex. Age at first diagnosis presented as means were compared using the one-sample t-test. Results: In the DNBC, the selected childhood psychiatric diagnoses were underrepresented by 3% (PR=0.97, 95% CI 0.94-0.99), ranging from a 20% underrepresentation for schizophrenia (PR=0.80, 95% CI 0.59-1.09) to a 6% over-representation for anxiety disorder or obsessive-compulsive disorder (PR=1.06, 95% CI 0.97-1.17). The majority of the specific diagnoses were modestly underrepresented in the DNBC compared to the general population, while use of psychotropic medication had similar representation. Girls were generally more underrepresented than boys. Depression was on average diagnosed 0.4 years earlier in the DNBC than in the general population (p=0.023). Conclusions: These findings suggest that the social selection may influence the prevalence of diagnosed childhood psychiatric disorders in the DNBC.

[The epidemiology of pharmacologically treated attention deficit hyperactivity disorder (ADHD) in the Region of Murcia, Spain: Differences by gender, age and location of residence]

INTRODUCTION

Attention deficit hyperactivity disorder (ADHD) is the most frequent disorder in childhood and adolescence, and is seen as a public health problem. The recommended treatment includes pharmacological and psychosocial treatment. The aim of this work was to study the changes in the prescribing of the medicines used in ADHD treatment in the Region of Murcia, as well as their socio-demographic variability.

METHOD

A retrospective observational study was conducted using the dispensing of medicines for ADHD treatment by means of prescription in the Region of Murcia from 2010 to 2014. The consumption rates were determined as defined daily doses (DDD) per thousand inhabitants/day (DHD), stratified by gender and age. The reasons for prevalence of treatment by gender were also determined by comparing male and female consumption rates.

RESULTS

The consumption of medicines for ADHD treatment had almost doubled in the period studied, from 5.58 DHD and 3.39 DHD in 2010 to 9.34 DHD and 6.71 DHD in 2014, for the age range of 10-14 and 15-19, respectively. Boys from 10-14 showed the highest consumption rates, showing a high geographical variability with less consumption in rural areas.

CONCLUSION

The results showed a large increase in the use of medicines for ADHD treatment in the Region of Murcia, although the consumption rates are still lower than in other Autonomous Communities or neighbouring countries. A wide geographical variability was found, with a higher consumption in adolescents from urban areas.

Association Between Medication Use for Attention-Deficit/Hyperactivity Disorder and Risk of Motor Vehicle Crashes

IMPORTANCE

Motor vehicle crashes (MVCs) are a major public health problem. Research has demonstrated that individuals with attention-deficit/hyperactivity disorder (ADHD) are more likely to experience MVCs, but the effect of ADHD medication treatment on the risk of MVCs remains unclear.

OBJECTIVE

To explore associations between ADHD medication use and risk of MVCs in a large cohort of patients with ADHD.

DESIGN, SETTING, AND PARTICIPANTS

For this study, a US national cohort of patients with ADHD (n = 2 319 450) was identified from commercial health insurance claims between January 1, 2005, and December 31, 2014, and followed up for emergency department visits for MVCs. The study used within-individual analyses to compare the risk of MVCs during months in which patients received ADHD medication with the risk of MVCs during months in which they did not receive ADHD medication.

EXPOSURES

Dispensed prescription of ADHD medications.

MAIN OUTCOMES AND MEASURES

Emergency department visits for MVCs.

RESULTS

Among 2 319 450 patients identified with ADHD, the mean (SD) age was 32.5 (12.8) years, and 51.7% were female. In the within-individual analyses, male patients with ADHD had a 38% (odds ratio, 0.62; 95% CI, 0.56-0.67) lower risk of MVCs in months when receiving ADHD medication compared with months when not receiving medication, and female patients had a 42% (odds ratio, 0.58; 95% CI, 0.53-0.62) lower risk of MVCs in months when receiving ADHD medication. Similar reductions were found across all age groups, across multiple sensitivity analyses, and when considering the long-term association between ADHD medication use and MVCs. Estimates of the population-attributable fraction suggested that up to 22.1% of the MVCs in patients with ADHD could have been avoided if they had received medication during the entire follow-up.

CONCLUSIONS AND RELEVANCE

Among patients with ADHD, rates of MVCs were lower during periods when they received ADHD medication. Considering the high prevalence of ADHD and its association with MVCs, these findings warrant attention to this prevalent and preventable cause of mortality and morbidity.

Utilization of Stimulants and Atomoxetine for Attention-Deficit/Hyperactivity Disorder among 5.4 Million Children Using Population-Based Longitudinal Data

Use of stimulants to treat attention-deficit/hyperactivity disorder (ADHD) has increased over the past two decades and varies substantially between countries. The objective of this multinational population-based study was to examine utilization of ADHD drugs (stimulants and atomoxetine) including comedication with other psychotropic drugs in the entire child population in the five Nordic countries. We included longitudinal data on dispensed ADHD drugs from five Nordic prescription registers during 2008-2012, which in 2012 comprised 48,296 individuals among 5.42 million inhabitants aged 0-17 years. Prevalence of filling ≥1 prescriptions of ADHD drugs among children aged 6-17 years increased during 2008-2012 from 5.9 to 11.2 and 19.4 to 31.0 per 1000 girls and boys, respectively. Prevalence by country showed that Iceland, Finland and Sweden had a steady increase during the study period, while in Norway the prevalence was quite stable and in Denmark it levelled off from 2010. Use in preschoolers (aged 0-5 years) was rare. Iceland had much higher prevalence and incidence than the other Nordic countries. The incidence of ADHD drug use increased during the study period, from 4.0 to 4.9 and from 1.5 to 2.3 per 1000 boys and girls, respectively. The increasing number of new users levelled off somewhat after 2010. Comedication with other psychotropic drugs was more common among girls (33.9%) than boys (27.0%) and was mainly melatonin, followed by antidepressants and antipsychotics. Overall prevalence of ADHD drug use increased among Nordic girls and boys aged 6-17 years, whereas the incidence increased slightly during 2008-2010 but levelled off through 2012. The substantial differences in ADHD drug use across the Nordic countries and high degree of comedication with other psychotropic drugs underscore the importance of close monitoring of treatment for ADHD among children.

Long-Term Efficacy of Methylphenidate Immediate-Release for the Treatment of Childhood ADHD

OBJECTIVE

To evaluate the long-term effects of methylphenidate imediate-release (MPH-IR), and to confirm the efficacy established in previous meta-analyses of short-term studies.

METHOD

Published and unpublished studies in which participants were treated with MPH-IR for 12 weeks or more were searched. Pooled effect sizes from these studies were computed with the DerSimonian and Laird random-effect model. Meta-regression analysis was conducted to estimate covariates associated with treatment effects.

RESULTS

Seven studies were included. Pooled parents ratings for inattention and hyperactivity/impulsivity resulted in standardized mean difference (SMD) = 0.96 (95% confidence interval [CI] = [0.60, 1.32]) and SMD = 1.12 (95% CI = [0.85, 1.39]), respectively; pooled teachers ratings showed SMD = 0.98 (95% CI = [0.09, 1.86]) for inattention and SMD = 1.25 (95% CI = [0.7, 1.81]) for hyperactivity/impulsivity. No evidence of association of any covariates with treatment effect was detected in the meta-regression.

CONCLUSION

MPH-IR is efficacious for childhood ADHD for periods longer than 12 weeks.

Medication for Attention-Deficit/Hyperactivity Disorder and Risk for Depression: A Nationwide Longitudinal Cohort Study

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is associated with high rates of psychiatric comorbidity, including depression. However, it is unclear whether ADHD medication increases or decreases the risk for depression.

METHODS

We studied all individuals with a diagnosis of ADHD born between 1960 and 1998 in Sweden (N = 38,752). We obtained data for prescription of ADHD medication, diagnosis of depression and other psychiatric disorders, and sociodemographic factors from population-based registers. The association between ADHD medication and depression was estimated with Cox proportional hazards regression.

RESULTS

After adjustment for sociodemographic and clinical confounders, ADHD medication was associated with a reduced long-term risk (i.e., 3 years later) for depression (hazard ratio = 0.58; 95% confidence interval, 0.51-0.67). The risk was lower for longer duration of ADHD medication. Also, ADHD medication was associated with reduced rates of concurrent depression; within-individual analysis suggested that occurrence of depression was 20% less common during periods when patients received ADHD medication compared with periods when they did not (hazard ratio = 0.80; 95% confidence interval, 0.70-0.92).

CONCLUSIONS

Our study suggests that ADHD medication does not increase the risk of later depression; rather, medication was associated with a reduced risk for subsequent and concurrent depression.

Gender ratios of administrative prevalence and incidence of attention-deficit/hyperactivity disorder (ADHD) across the lifespan: A nationwide population-based study in Taiwan

To verify the hypothesis that there is different gender ratio of attention-deficit/hyperactivity disorder (ADHD) among adults compared to children and adolescents in the clinical setting among Asian population. The nationwide population-based database containing data on enrollees in the National Health Insurance program in Taiwan during 2000-2007 was used in this study, and we investigated the lifetime gender ratios of administrative prevalence and incidence in healthcare-seeking ADHD patients (n=228,029). The male-to-female ratios of diagnosed incidence and prevalence of child/adolescent ADHD (age <20 years) ranged from 3.39 to 4.07 and 3.87-4.31, respectively. The male-to-female ratios of diagnosed incidence and prevalence of ADHD in the adult group (age 20-65 years) ranged from 0.24 to 0.76 and 0.35-0.98, respectively. In conclusion, there was substantially increased female-to-male ratio in adults ADHD compared to children and adolescents in the clinical setting. Further researches on the management and mechanism are needed.

Variability and trends in the consumption of drugs for treating attention-deficit/hyperactivity disorder in Castile-La Mancha, Spain (1992-2015)

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common behavioural disorders of childhood; its prevalence in Spain is estimated at 5-9%. Available treatments for this condition include methylphenidate, atomoxetine, and lisdexamfetamine, whose consumption increases each year.

MATERIAL AND METHODS

The prevalence of ADHD was estimated by calculating the defined daily dose per 1,000 population per day of each drug and the total doses (therapeutic group N06BA) between 1992 and 2015 in each of the provinces of Castile-La Mancha (Spain). Trends, joinpoints, and annual percentages of change were analysed using joinpoint regression models.

RESULTS

The minimum prevalence of ADHD in the population of Castile-La Mancha aged 5 to 19 was estimated at 13.22 cases per 1,000 population per day; prevalence varied across provinces (p<.05). Overall consumption has increased from 1992 to 2015, with an annual percentages of change of 10.3% and several joinpoints (2000, 2009, and 2012). methylphenidate represents 89.6% of total drug consumption, followed by lisdexamfetamine at 8%.

CONCLUSIONS

Analysing drug consumption enables us to estimate the distribution of ADHD patients in Castile-La Mancha. Our data show an increase in the consumption of these drugs as well as differences in drug consumption between provinces, which reflect differences in ADHD management in clinical practice.

Use of drugs for ADHD among adults-a multinational study among 15.8 million adults in the Nordic countries

Purpose

The use of ADHD drugs among adults is controversial and has until recently not been approved for use in adults in most countries. The aim was to investigate use of ADHD drugs (stimulants and atomoxetine) among the entire adult population in the Nordic countries.

Methods

We conducted a multinational population-based prescription register study based on the entire adult population in the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). All users of ADHD drugs aged 18–64 years during 2008–2012 were included, which for 2012 comprised 76,896 drug users among 15.8 million adult inhabitants.

Results

Annual prevalence of drug use increased during the study period for both genders and all age groups. The overall prevalence increased from 2.4 to 5.3 per 1000 men and 1.8 to 4.4 per 1000 women. Incidence also increased, but to a lesser extent in the last part of the study period. Methylphenidate was used by 88 % of drug users. Treatment was discontinued within the first year by 21 % of new drug users. Among all users of ADHD drugs, 53 % of men and 64 % of women concurrently used other psychotropic drugs, most frequently antidepressants and hypnotics. Psychotropic co-medication increased with age and was more pronounced among women than men.

Conclusions

Use of ADHD drug among adults more than doubled over a 5-year period, and a majority were concurrently treated with other psychotropics. Adults constitute a substantial proportion of persons treated with ADHD drugs. Thus, evidence for long-term efficacy and safety in adults is urgently needed.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-016-2125-y) contains supplementary material, which is available to authorized users.

Initiation and Persistence of Pharmacotherapy for Youths with Attention Deficit Hyperactivity Disorder in Taiwan

BACKGROUND

Pharmacotherapy is an effective therapeutic option for attention deficit hyperactivity disorder (ADHD). Understanding the patterns of medication treatment is crucial for clinical practice. This study employed nationwide population-based data to elucidate the initiation and persistence of pharmacotherapy (immediate-release methylphenidate [IR-MPH], osmotic controlled-release formulations of methylphenidate [OROS-MPH] and atomoxetine [ATX]) for youths with ADHD in Taiwan.

METHODS

Patients first receiving an ADHD diagnosis at age 18 or younger between January 2000 and December 2009 (n = 112,140; mean age at ADHD diagnosis: 7.7 years) were selected from Taiwan's National Health Insurance database. All patients were monitored through December 31, 2011, with an average follow-up time of 5.8 years. The initiation of ADHD drug therapy was defined as the first patient prescription, and discontinuation was defined as the cessation of ADHD medication for 180 days or longer.

RESULTS

Within the first year after ADHD diagnosis, 47.3%, 14.4%, and 0.8% of the patients were prescribed IR-MPH, OROS-MPH, and ATX, respectively. Regarding the patients prescribed IR-MPH, OROS-MPH, and ATX, 17.8%, 12.6%, and 18.8%, respectively, received the prescription only once and never returned for a drug refill, and 51.0%, 38.9%, and 58.8%, respectively, discontinued drug therapy within 1 year after the first prescription. Male sex and neuropsychiatric comorbidities were associated with higher probabilities of being prescribed one of the medications. An older age at first prescription and a higher daily dose of prescription were significant predictors of early discontinuation of ADHD medication.

CONCLUSIONS

The current findings suggest that IR-MPH is the most frequently prescribed drug for ADHD treatment in Taiwan. Patients treated with OROS-MPH possessed the highest persistence rate, whereas those treated with ATX had the lowest persistence rate. The results provide insight into the delivery of pediatric mental health services and have crucial implications for ADHD medication treatment in real clinical settings.

'Big data' in mental health research: current status and emerging possibilities

PURPOSE

'Big data' are accumulating in a multitude of domains and offer novel opportunities for research. The role of these resources in mental health investigations remains relatively unexplored, although a number of datasets are in use and supporting a range of projects. We sought to review big data resources and their use in mental health research to characterise applications to date and consider directions for innovation in future.

METHODS

A narrative review.

RESULTS

Clear disparities were evident in geographic regions covered and in the disorders and interventions receiving most attention.

DISCUSSION

We discuss the strengths and weaknesses of the use of different types of data and the challenges of big data in general. Current research output from big data is still predominantly determined by the information and resources available and there is a need to reverse the situation so that big data platforms are more driven by the needs of clinical services and service users.

Prevalent intravenous abuse of methylphenidate among treatment-seeking patients with substance abuse disorders: a descriptive population-based study

Objectives:

Prescription rates of methylphenidate (MPH) are sharply rising in most Western countries. Although it has been reported that MPH has abuse potential, little is known about the prevalence of intravenous (IV) abuse of MPH. The aim of the study was to investigate the prevalence of IV MPH abuse among treatment-seeking IV substance abusers in Iceland.

Methods:

This is a descriptive population-based study using a semistructured interview assessing sociodemographics, substance abuse history, and the method of administration of 108 IV substance abusers. During 1 year, consecutively admitted adult inpatients with substance use disorder at any detoxification center in Iceland that reported any IV substance abuse in the past 30 days were invited to participate. Abuse was defined as nontherapeutic use of a substance to gain psychological or physiological effect.

Results:

Prevalence of any IV MPH abuse among participants was 88% in the last 30 days (95% confidence interval [CI], 0.82-0.94) and MPH was the most commonly abused substance (65%) and the preferred substance (63%). Around one third (30%) reported MPH as the first IV substance ever abused. However, among those reporting a shorter history than 10 years of IV abuse, 42% reported MPH as the first IV substance ever abused.

Conclusions:

This first nationwide study on IV abuse of MPH shows that it is common among treatment-seeking IV abusers in Iceland and suggests that MPH has high abuse potential. Therefore, both the use and possible abuse of MPH in those with high abuse potential should be monitored, especially in countries where MPH prescriptions rates are on the rise.

Changing tides: Adaptive monitoring, assessment, and management of pharmaceutical hazards in the environment through time

Pharmaceuticals are ubiquitous contaminants in aquatic ecosystems. Adaptive monitoring, assessment, and management programs will be required to reduce the environmental hazards of pharmaceuticals of concern. Potentially underappreciated factors that drive the environmental dose of pharmaceuticals include regulatory approvals, marketing campaigns, pharmaceutical subsidies and reimbursement schemes, and societal acceptance. Sales data for 5 common antidepressants (duloxetine [Cymbalta], escitalopram [Lexapro], venlafaxine [Effexor], bupropion [Wellbutrin], and sertraline [Zoloft]) in the United States from 2004 to 2008 were modeled to explore how environmental hazards in aquatic ecosystems changed after patents were obtained or expired. Therapeutic hazard ratios for Effexor and Lexapro did not exceed 1; however, the therapeutic hazard ratio for Zoloft declined whereas the therapeutic hazard ratio for Cymbalta increased as a function of patent protection and sale patterns. These changes in therapeutic hazard ratios highlight the importance of considering current and future drivers of pharmaceutical use when prioritizing pharmaceuticals for water quality monitoring programs. When urban systems receiving discharges of environmental contaminants are examined, water quality efforts should identify, prioritize, and select target analytes presently in commerce for effluent monitoring and surveillance.

Psychotropic medicine prescriptions in Italian youths: a multiregional study

The aim of the study was to evaluate the trend of paediatric psychotropic drug prescriptions in Italy. Data sources were regional, outpatient prescription databases. Seven Italian regions, covering 50 % of the Italian population, provided data from 2006 to 2011. Prevalence and incidence of prescriptions by age and gender were evaluated for psychotropic, antidepressant, antipsychotic, and attention-deficit/hyperactivity disorders (ADHD) medications. The hospital admission rate for psychiatric conditions was calculated, also at the local health unit (LHU) level. The presence of trends in prescription prevalence and incidence during the 6 year period was assessed. Finally, the correlation between prevalence, prescription, hospital admission rates, latitude, longitude, and average annual income at the LHU level was also investigated. In 2011, 8834 youths received at least one psychotropic drug prescription, with a prevalence of 1.76 ‰ (95 % CI 1.72-1.80). The incidence of new psychotropic drug users was 1.03 ‰ (1.00-1.06). The prevalence of antidepressants was 1.02 ‰ (0.99-1.04), while that of antipsychotics was 0.70 ‰ (0.68-0.72), and that of ADHD medications 0.19 ‰ (0.18-0.21). The psychotropic drug prevalence increased with increasing age. Males were more exposed to psychotropic drugs than females (AUC0-17 male/female = 1.23). Antipsychotics were the most prescribed psychotropic drugs in males, while antidepressants were in females. Between-region prevalence ranged from 1.56 to 2.17 ‰. The overall prevalence of psychotropic drug from 2006 to 2011 was stable (χ(t)2 ≤ 0.001, p = 0.97). No correlation was found between prevalence and the variables investigated. Psychotropic drug prescription was very limited and stable. No geographical patterns were found.

Psychotropic drug use among 0-17 year olds during 2004-2014: a nationwide prescription database study

BACKGROUND

Time-trend studies on psychotropic drugs among children and adolescents are scarce, and most of them are outdated. The purpose of this study was to study prevalences of psychotropic drug use during 2004-2014 among Norwegians aged <18 years, overall and in psychotropic sub-groups.

METHODS

Data were obtained from the Norwegian Prescription Database, which covers all dispensed prescription drugs in Norway from 2004 and onwards. Psychotropic drugs included: antipsychotics (ATC-group N05A), anxiolytics (N05B), hypnotic/sedatives (N05C), antidepressants (N06A), stimulants (N06BA), and alimemazine (R06AD01). Period (1-year) prevalence of use, overall and in subgroups of psychotropic drugs, was estimated by identifying individuals <18 years who had at least one psychotropic drug dispensed during each year.

RESULTS

Psychotropic drug use increased in 0-17 year olds over an 11-year period, in which the main contributing drugs were stimulants (boys overall; 15.0 to 20.8/1000, girls overall; 3.8 to 8.5/1000), hypnotic/sedative drugs in adolescents (boys overall; 4.2 to 10.8/1000, girls overall; 2.6 to 8.8/1000) and to some extent antidepressants among adolescent girls (girls overall from 3.1 to 4.0/1000). Psychotropic drug use was, however, reduced by half in the youngest children, attributed to reduction of alimemazine only (1-year olds: boys; from 36.6 to 10.2/1000, girls; 26.9 to 7.2/1000). A higher level of psychotropic drug use was observed among younger boys, but there is a shift towards girls using more psychotropic drugs than boys during adolescence for all psychotropic drugs except for stimulants.

CONCLUSION

Different trends in psychotropic drug use exist in age and gender subgroups. Psychotropic drug use has decreased among the youngest children, attributed to alimemazine, and increased in older children and adolescents, attributed mainly to stimulants and hypnotics/sedatives.

Non-obsessive-compulsive anxiety disorders in child and adolescent mental health services--Are they underdiagnosed, and how accurate is referral information?

BACKGROUND

Previous studies have reported low prevalence of non-obsessive-compulsive (OCD) anxiety disorders in child and adolescent mental health services (CAMHSs), suggesting that these disorders may go unrecognized. Possible reasons may be lack of routinely used standardized diagnostic instruments, and/or an under-reporting of anxiety symptoms in the referral information.

AIMS

To examine the frequency of non-OCD anxiety disorders in referred children based on a standardized diagnostic interview, to compare the results with data from the Norwegian Patient Register (NPR), and to explore the correspondence between anxiety as a referral symptom and anxiety as a diagnosis, and the influence of heterotypic co-morbidity on this correspondence.

METHODS

Parents of 407 consecutive referrals to CAMHS aged 7-13 years were interviewed with the semi-structured diagnostic interview Kiddie-SADS-PL at the time of admittance. Referral symptoms were collected from national referral forms.

RESULTS

A total of 133 referred children (32.7%) met the criteria for a non-OCD anxiety disorder compared with about 5% in the NPR. Half of those who met diagnostic criteria for an anxiety disorder did not have anxiety as a referral symptom. Co-morbid ADHD or disruptive disorder was significantly associated with a lower probability of having anxiety as a referral symptom.

CONCLUSIONS

The use of a standardized diagnostic interview in consecutively referred children yielded significantly higher rates of anxiety disorders than the NPR prevalence rates. Co-morbid ADHD or disruptive disorder may contribute to the underdiagnosing of anxiety disorders. Diagnostic instruments covering the whole range of child psychiatric symptoms should be implemented routinely in CAMHS.

Use of SSRI and SNRI Antidepressants during Pregnancy: A Population-Based Study from Denmark, Iceland, Norway and Sweden

Background

The purpose was to describe utilization of selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs), including trends in prevalence, characteristics of users, drug switching and changes in prescribed doses in a large group of pregnant women across four Nordic countries.

Methods

A drug utilization study based on linked individual-level data from the nationwide prescription- and medical birth registers in Denmark, Iceland, Norway and Sweden. The study population comprised all pregnancies in these countries, resulting in a live birth or stillbirth after gestational week 22 from January 1^st 2008 to December 31^st 2012 (N = 1 162 470). In addition to the main study drugs SSRIs and SNRIs, we included (concurrent) use of other antidepressants, antipsychotics, anxiolytics and hypnotics.

Results

A total of 38 219 (3.3%) pregnancies were exposed to SSRIs and 5 634 (0.5%) to SNRIs. Prevalence of SSRI and SNRI use varied by country (1.8% in Norway to 7.0% in Iceland). Use and prescribed dosages decreased with each passing trimester of pregnancy; prevalence was 2.7% at conception, and 2.1%, 1.7% and 1.3% respectively in 1^st, 2^nd and 3^rd trimester. In 0.6% of pregnancies women filled a prescription before pregnancy and in every trimester. In one third of exposed pregnancies, women were also dispensed anxiolytics, hypnotics or sedatives.

Conclusion

Use of SSRI and SNRI use during pregnancy varied between the Nordic countries, but the overall prevalence remained low and relatively stable from 2008 to 2012. The low prevalence of use and high proportion of women who discontinue treatment in pregnancy raise questions about adequate treatment of depression in pregnant women.

Recent international trends in psychotropic medication prescriptions for children and adolescents

Prescriptions of psychotropic medications have become an important intervention for many children and adolescents with mental disorders, and the rise of these prescriptions is debated intensively both among experts and the public. This review reports some recent international findings on point prevalence rates, cross-country comparisons, and time trends in psychotropic medication prescriptions for children and adolescents. Besides the total prescription rates, figures for antidepressants, antipsychotics, stimulants, and anxiolytics prescriptions are provided. The overall prescription rates of psychotropics in general and the major medication subgroups prescribed to children and adolescents vary substantially between countries with the US consumption being markedly higher than the use in European countries. However, even among the latter there are marked variations in findings. Studies reporting on time trends clearly indicate that there was a marked increase in the use of psychotropics for children and adolescents in the recent past. However, only a single study adjusted prevalence rates for the increasing number of children and adolescents assessed and treated in institutions providing mental health care. Considering the increasing numbers of children and adolescents seen in psychiatric services, the increase of psychotropic medications is less strong though still pronounced enough to stimulate further reflections on the use of these interventions.

Social adversity and regional differences in prescribing of ADHD medication for school-age children

OBJECTIVES

To explore whether regional variations in the initiation of attention-deficit hyperactivity disorder (ADHD) medication among school-age children are explained by differences in sociodemographic composition and/or ADHD prescribing practice, especially in children who face social adversity (low parental education and single parenthood).

METHODS

A cohort of Danish school-age children (ages 5-17) without previous psychiatric conditions (N = 813,416) was followed during 2010-2011 for incident ADHD prescribing in the individual-level Danish registers. Register information was retrieved for both children and their parents. Regional differences were decomposed into contributions from differences in sociodemographic composition and in prescribing practices. Incidence rate ratios (IRR) with 95% confidence interval (CI) of ADHD prescribing were calculated using demographically standardized multivariable Poisson regression models.

RESULTS

Compared with the Capital, prescribing rates were significantly higher in regions North and Zealand (IRR, 1.19; 95% CI, 1.08-1.32 and 1.17; 1.08-1.28, respectively) and lower in South (IRR, 0.60; 95% CI, 0.54-0.66). After inclusion of the interaction term (region*social adversity), the multivariable analyses revealed a higher rate for the most disadvantaged children in North (IRR, 2.00; 95% CI, 1.51-2.66) and a lower rate in South (IRR, 0.47; 95% CI, 0.3-0.65). Prescribing rates were the highest for disadvantaged children in all regions, demonstrating the steepest social gradient in North and the smoothest in South. Demographic composition explained little of the variation: 3% for North and 13% for Zealand.

CONCLUSIONS

Differences in sociodemographic composition explain little of regional variation in incident ADHD prescribing for children. However, large regional differences prevail in prescribing practices for children facing social adversity, indicating that local cultures shape the interpretation and handling of children with ADHD-like behaviors.

A systematic review of reboxetine for treating patients with attention deficit hyperactivity disorder

BACKGROUND

No published systematic review has ever assessed the efficacy and safety of reboxetine for treating of patients with attention deficit hyperactivity disorder (ADHD).

AIM

This systematic review aimed to review the available evidence regarding the efficacy of reboxetine for treating ADHD.

METHOD

The databases of Pubmed/Medline, Google scholar, SCOPUS and Web of Science were searched using the Keywords: "reboxetine", "ADHD" and "attention deficit hyperactivity disorder". The reference lists of the included studies were screened to find any possible other relevant articles. All the non-controlled and controlled clinical trials were included.

RESULTS

The current evidence mainly consists of un-controlled studies, such as case series. Only three of 33 studies were controlled clinical trials. They are from single sites and included a sub-sample of patients with ADHD.

CONCLUSION

Non-controlled studies and controlled trials support the promising effect of reboxetine for treating ADHD in a sub-sample of patients that are without co-morbid psychiatric disorder and mental retardation. Reboxetine is tolerated well. However, more controlled trials are needed to reach any firm conclusion.

Effectiveness of one-year pharmacological treatment of adult attention-deficit/hyperactivity disorder (ADHD): an open-label prospective study of time in treatment, dose, side-effects and comorbidity

How to generalize from randomized placebo controlled trials of ADHD drug treatment in adults to 'real-world' clinical practice is intriguing. This open-labeled prospective observational study examined the effectiveness of long-term stimulant and non-stimulant medication in adult ADHD including dose, side-effects and comorbidity in a clinical setting. A specialized ADHD outpatient clinic gave previously non-medicated adults (n=250) with ADHD methylphenidate as first-line drug according to current guidelines. Patients who were non-tolerant or experiencing low efficacy were switched to amphetamine or atomoxetine. Primary outcomes were changes of ADHD-symptoms evaluated with the Adult ADHD Self-Report Scale (ASRS) and overall severity by the Global Assessment of Functioning (GAF). Secondary outcomes were measures of mental distress, and response on the Clinical-Global-Impressions-Improvement Scale. Data at baseline and follow-ups were compared in longitudinal mixed model analyses for time on-medication, dosage, comorbidity, and side-effects. As results, 232 patients (93%) completed examination at the 12 month endpoint, and 163 (70%) remained on medication. Compared with the patients who discontinued medication, those still on medication had greater percentage reduction in ASRS-scores (median 39%, versus 13%, P<0.001) and greater improvement of GAF (median 20% versus 4%, P<0.001) and secondary outcomes. Continued medication and higher cumulated doses showed significant associations to sustained improvement. Conversely, psychiatric comorbidity and side-effects were related to lower effectiveness and more frequent termination of medication. Taken together, one-year treatment with stimulants or atomoxetine was associated with a clinically significant reduction in ADHD symptoms and mental distress, and improvement of measured function. No serious adverse events were observed.

Nationwide rate of attention-deficit hyperactivity disorder diagnosis and pharmacotherapy in Korea in 2008-2011

INTRODUCTION

Using the National Health Insurance database in Korea, we examined the diagnostic and treatment incidence and comorbidity of attention-deficit hyperactivity disorder (ADHD).

METHODS

During 2007-2011, we chose subjects aged 6-18 years, who had at least one medical claim containing an International Classification of Diseases, 10th Revision code for diagnosis of ADHD (F90.0) with no medication use in the previous 360 days. Then, we analyzed the data for 2008-2011 to determine the mean annual incidence and prevalence of newly diagnosed and medicated patients, as well as comorbidity.

RESULTS

The average annual diagnostic incidence of ADHD was 0.357% (29,310.5/8,218,252), and the incidence of medication use for ADHD was 0.248% (20,340.3/8,218,252) during 2008-2011 with no significant annual difference. The transition rate from diagnosis to medication among newly diagnosed ADHD patients was 69%. The overall prevalence rate of ADHD diagnosis and medication during 2008-2011 was 0.799% (65,702/8,218,252) and 0.610% (50,127/8,218,252), respectively. Among newly diagnosed patients with ADHD, osmotic-controlled release oral delivery system methylphenidate was the most commonly used first medication, and depression was the most common comorbid psychiatric diagnosis.

DISCUSSION

This is the first report of the nationwide data on the current diagnosis and pharmacotherapy of ADHD in the whole population aged 6-18 years. We need further investigation to find the factors of low diagnostic and treatment incidence compared with high prevalence of ADHD.

Children's relative age in class and use of medication for ADHD: a Danish Nationwide Study

BACKGROUND

Previous studies from North America and Iceland have shown that the youngest children within a grade are up to twice as likely to be diagnosed and treated for attention-deficit/hyperactivity disorder (ADHD) compared with their older classmates. We aimed to investigate whether younger age in class is associated with an increased probability of being prescribed medication for ADHD among school-aged children in Denmark.

METHODS

We followed all Danish children between 2000 and 2012 from 1st through 6th grade (7-12 years). Among children who started school on their age-assigned grade level, we estimated the prevalence proportion ratio (PPR) of receiving ADHD medication between the youngest children in class (born in October-December) and the oldest in class (born in January-March), specified by grade level, calendar year and gender. As a sensitivity analysis, we added children not on their age-assigned grade level to the main calculations.

RESULTS

We identified 932,032 eligible children for the main analysis, of whom 17.3% were among the youngest and 26.5% among the oldest in class. In total, 1.2% eligible children filled at least one prescription for ADHD medication in 2000-2012. The average PPR over the study period was 1.08 (95% CI, 1.04-1.12) and remained stable across subgroups and sensitivity analyses. Overall, 40% of children born October-December had entered school a year after their age-assigned grade level.

CONCLUSIONS

Contrary to previous study results, we observed almost no relative age effect on medication use for ADHD among children in Denmark. We postulate that this may be due to the high proportion of relatively young children held back by 1 year in the Danish school system and/or a generally low prevalence of ADHD medication use in the country.

Stimulant ADHD medication and risk for substance abuse

BACKGROUND

There are persistent concerns of long-term effects of stimulant ADHD medication on the development of substance abuse.

METHODS

Using Swedish national registers, we studied all individuals born between 1960 and 1998 and diagnosed with ADHD (26,249 men and 12,504 women). We investigated the association between stimulant ADHD medication in 2006 and substance abuse during 2009. Substance abuse was indexed by substance-related death, crime, or hospital visits.

RESULTS

ADHD medication was not associated with increased rate of substance abuse. Actually, the rate during 2009 was 31% lower among those prescribed ADHD medication in 2006, even after controlling for medication in 2009 and other covariates (hazard ratio: 0.69; 95% confidence interval: 0.57-0.84). Also, the longer the duration of medication, the lower the rate of substance abuse. Similar risk reductions were suggested among children and when investigating the association between stimulant ADHD medication and concomitant short-term abuse.

CONCLUSIONS

We found no indication of increased risks of substance abuse among individuals prescribed stimulant ADHD medication; if anything, the data suggested a long-term protective effect on substance abuse. Although stimulant ADHD medication does not seem to increase the risk for substance abuse, clinicians should remain alert to the potential problem of stimulant misuse and diversion in ADHD patients.

Relative immaturity and ADHD: findings from nationwide registers, parent- and self-reports

BACKGROUND

We addressed if immaturity relative to peers reflected in birth month increases the likelihood of ADHD diagnosis and treatment.

METHODS

We linked nationwide Patient and Prescribed Drug Registers and used prospective cohort and nested case-control designs to study 6-69 year-old individuals in Sweden from July 2005 to December 2009 (Cohort 1). Cohort 1 included 56,263 individuals diagnosed with ADHD or ever used prescribed ADHD-specific medication. Complementary population-representative cohorts provided DSM-IV ADHD symptom ratings; parent-reported for 10,760 9-year-old twins born 1995-2000 from the CATSS study (Cohort 2) and self-reported for 6,970 adult twins age 20-47 years born 1959-1970 from the STAGE study (Cohort 3). We calculated odds ratios (OR:s) for ADHD across age for individuals born in November/December compared to January/February (Cohort 1). ADHD symptoms in Cohorts 2 and 3 were studied as a function of calendar birth month.

RESULTS

ADHD diagnoses and medication treatment were both significantly more common in individuals born in November/December versus January/February; peaking at ages 6 (OR: 1.8; 95% CI: 1.5-2.2) and 7 years (OR: 1.6; 95% CI: 1.3-1.8) in the Patient and Prescribed Drug Registers, respectively. We found no corresponding differences in parent- or self-reported ADHD symptoms by calendar birth month.

CONCLUSION

Relative immaturity compared to class mates might contribute to ADHD diagnosis and pharmacotherapy despite absence of parallel findings in reported ADHD symptom loads by relative immaturity. Increased clinical awareness of this phenomenon may be warranted to decrease risk for imprecise diagnostics and treatment. We speculate that flexibility regarding age at school start according to individual maturity could reduce developmentally inappropriate demands on children and improve the precision of ADHD diagnostic practice and pharmacological treatment.