Rise in psychotropic drug prescribing in children and adolescents during 1992–2001: a population-based study in the UK

Psychotropic medication use among adolescents participating in three randomized trials of DBT

BACKGROUND

Frequently presenting with symptoms of mood or anxiety disorders, substance abuse or borderline personality disorder, suicidal and self-harming adolescents often are prescribed psychotropic medication. Though such treatment may be warranted, recurrent suicidal and self-harming behaviour is often linked to emotion dysregulation where pharmacological treatment has weak empirical support. There is a need for more clinical research into the frequency, type and rationale for pharmacological treatment in this group. In this secondary analysis of three randomized clinical trials of dialectical behaviour therapy for adolescents, we report on psychotropic medication use in the respective samples at the time of recruitment, compare use of psychotropic medication across trials and describe sample characteristics that may be associated with possible differences in psychotropic medication.

FINDINGS

Trials were conducted in Norway, the US and Spain (labelled the Oslo, US and Barcelona samples). At baseline, 86% of the Barcelona sample, 67% of the US sample and 12% of the Oslo sample were taking at least one psychotropic medication with antidepressants as the most frequent, followed by antipsychotics (72%, 22% and 1.3% respectively) and mood stabilizers (14.2%, 16.2% and 0%). In the Oslo sample there was a significant association between receiving a diagnosis of major depression and the likelihood of receiving antidepressants, but no such association was found in the Barcelona and US samples. The overall 7-8 times higher proportion of participants in the US and Barcelona samples treated with psychotropic medication could only partially be explained by differences between the samples in diagnostic profiles, symptom severity or level of dysfunction.

CONCLUSIONS

Highly prevalent in use among suicidal and self-harming adolescents with borderline features, psychotropic medication was still very unevenly prescribed across trials, differences not explained by differences in sample characteristics suggesting that current treatment practices are not fully empirically supported. We call for continued medical education and increased availability of evidence-based psychosocial interventions.

Nationwide Rate of Adult ADHD Diagnosis and Pharmacotherapy from 2015 to 2018

There is a paucity of published literature on the epidemiology of adult attention-deficit/hyperactivity disorder (ADHD). We investigated the time trends of the diagnostic and pharmacotherapy incidence of ADHD, including the first used medication, in the adult population based on a Korean population-based database from 2015 to 2018. The number of diagnosed cases of ADHD significantly increased from 7782 in 2015 to 17,264 in 2018 (p = 0.03), which is 0.02% to 0.04% of the total population. Similarly, the number of pharmacotherapy cases of ADHD significantly increased from 3886 in 2015 to 12,502 in 2018 (p = 0.01), which is 0.01% to 0.03% of total population. The most commonly used medication at the initiation of pharmacotherapy shifted from Penid in 2015 to Concerta in 2018. Furthermore, combination therapy with two or more drugs was the preferred method in 2016–2018. In conclusion, the identified diagnoses and pharmacotherapy incidences were very low, highlighting the need to improve the public’s awareness of adult ADHD.

Medication Adherence in Adolescents with Psychiatric Disorders

Objective: This study investigates whether adolescents' adherence to psychotropic medication is associated with demographic and socioeconomic factors, and to what extent parents' assessments of their offspring's attitudes toward treatment correspond with the adolescents' self-report. Methods: This study is part of the multicenter SEMA study (Subjective Experience and Medication Adherence in Adolescents with Psychiatric Disorders). Adolescents' subjective attitudes toward medication and their adherence were assessed using the patient and parent versions of the QATT (Questionnaire on Attitudes Toward Treatment) and the MARS (Medication Adherence Rating Scale). Furthermore, we collected socioeconomic and demographic data. Results: Of the n = 75 adolescents included in the study, n = 45 (60 %) were classified as completely adherent. Patients receiving monotherapy were more often completely adherent than those receiving a combination of different medications. There was no statistically significant association between adherence and demographic or socioeconomic factors. Consensus between adolescents and their parents regarding adolescents' attitudes toward treatment ranged from slight (κ = 0.157) to fair (κ = 0.205). Conclusion: Incomplete medication adherence in adolescents with psychiatric disorders is a common phenomenon and still poorly understood. Demographic and socioeconomic factors do not seem to be relevant in this respect. However, adolescents' subjective attitudes towards medication, which parents are presumably unable to adequately assess, warrant more careful consideration in future research.

Psychotropic use in children and adolescents in Scandinavia and Catalonia: a 10-year population-based study

RATIONALE

The use of psychotropic drugs in the paediatric population has not been the subject of many studies, due to the fact that this population is generally not included in clinical trials and these drugs are not authorized for use on minors.

OBJECTIVES

This study aims to provide an accurate description of psychotropic drug use in children and adolescents in the North of Europe and Catalonia.

METHODS

Data from 2008 to 2017 on psychotropic drug consumption in children and adolescents were retrieved from the databases of Catalonia, Denmark, Norway and Sweden. Psychotropic drugs were divided into antipsychotics, anxiolytics (also hypnotics and sedatives), antidepressants and psychostimulants. Data were stratified by group of age (0-4, 5-9, 10-14 and 15-19/15-17 for Denmark and Catalonia) and sex.

RESULTS

Overall, the group of anxiolytics shows the highest consumption and the group of antipsychotics the lowest. In 2017, Sweden was the country with the highest consumption of psychotropic drugs (6.67‰) and has the highest increase in consumption (152.8%), and Denmark has the lowest consumption for all groups (3.13‰). Catalonia shows a decrease in psychotropic drugs (-15.9%). Girls consume more than twice as many antidepressants as boys while the opposite is true for psychostimulants. Risperidone and quetiapine are among the most consumed antipsychotics in the Nordic countries, whereas in Catalonia they are risperidone and aripiprazole. Among antidepressants, sertraline is the most consumed. No differences are found among the psychostimulants.

CONCLUSIONS

Psychotropic consumption in younger populations is increasing, although there are differences between the countries as far as which drugs are used. Nordic countries show a higher prevalence of use than Catalonia. Psychotropic drug consumption increases with age, except for psychostimulants, which have the highest utilization rate among 10-14-year-olds.

A computational method to quantitatively measure pediatric drug safety using electronic medical records

BACKGROUND

Drug safety in children is a major concern; however, there is still a lack of methods for quantitatively measuring, let alone to improving, drug safety in children under different clinical conditions. To assess pediatric drug safety under different clinical conditions, a computational method based on Electronic Medical Record (EMR) datasets was proposed.

METHODS

In this study, a computational method was designed to extract the significant drug-diagnosis associations (based on a Bonferroni-adjusted hypergeometric P-value < 0.05) among drug and diagnosis co-occurrence in EMR datasets. This allows for differences between pediatric and adult drug use to be compared based on different EMR datasets. The drug-diagnosis associations were further used to generate drug clusters under specific clinical conditions using unsupervised clustering. A 5-layer quantitative pediatric drug safety level was proposed based on the drug safety statement of the pediatric labeling of each drug. Therefore, the drug safety levels under different pediatric clinical conditions were calculated. Two EMR datasets from a 1900-bed children's hospital and a 2000-bed general hospital were used to test this method.

RESULTS

The comparison between the children's hospital and the general hospital showed unique features of pediatric drug use and identified the drug treatment gap between children and adults. In total, 591 drugs were used in the children's hospital; 18 drug clusters that were associated with certain clinical conditions were generated based on our method; and the quantitative drug safety levels of each drug cluster (under different clinical conditions) were calculated, analyzed, and visualized.

CONCLUSION

With this method, quantitative drug safety levels under certain clinical conditions in pediatric patients can be evaluated and compared. If there are longitudinal data, improvements can also be measured. This method has the potential to be used in many population-level, health data-based drug safety studies.

Attention-deficit/hyperactivity disorder: variation by socioeconomic deprivation

BACKGROUND

In England, there is a discrepancy between the prevalence of attention-deficit/hyperactivity disorder (ADHD) ascertained from medical records and community surveys. There is also a lack of data on variation in recorded prevalence by deprivation and geographical region; information that is important for service development and commissioning.

METHODS

Cohort study using data from the Clinical Practice Research Datalink comprising 5196 children and young people aged 3-17 years with ADHD and 490 016 without, in 2012.

RESULTS

In 2012, the recorded prevalence of ADHD was 1.06% (95% CI 1.03 to 1.09). Prevalence in the most deprived areas was double that of the least deprived areas (prevalence rate ratio 2.58 (95% CI 2.36 to 2.83)), with a linear trend from least to most deprived areas across all regions in England.

CONCLUSIONS

The low prevalence of ADHD in medical records may indicate considerable underdiagnosis. Higher rates in more disadvantaged areas indicate greater need for services in those areas.

Glucose and Prolactin Monitoring in Children and Adolescents Initiating Antipsychotic Therapy

OBJECTIVE

We aimed to evaluate glucose and prolactin monitoring in children and adolescents initiating antipsychotic therapy using a nationwide claims database.

METHODS

A retrospective 15-month cohort study was conducted using the National Database of Health Insurance Claim Information and Specified Medical Checkups in Japan. Patients aged ≤18 years, who were newly prescribed antipsychotics between April 2014 and March 2015, were followed up for 450 days. Outcomes were the use of glucose and prolactin testing through 15 months after drug initiation (index date) with consideration of persistence with antipsychotic therapy. The incidence proportion of patients monitored was assessed within the following four time windows: baseline (between 30 days before the index date and the index date), at 1-3 months (between 1 and 90 days after the index date), at 4-9 months (between 91 and 270 days after the index date), and at 10-15 months (between 271 and 450 days after the index date).

RESULTS

Of 43,608 new users in 6620 medical institutions, the percentage of persistent antipsychotic users was 46.4% at 90 days, 29.7% at 270 days, and 23.8% at 450 days after the index date. The proportion of patients who received monitoring within the baseline period was 13.5% (95% confidence interval [CI], 13.2-13.8) for glucose and 0.6% (95% CI, 0.5-0.6) for prolactin, respectively. The proportion of patients who received glucose monitoring at all time windows decreased to 0.9%. The proportion of patients who received prolactin monitoring by the second time window decreased to 0.1%.

CONCLUSIONS

Our study shows that monitoring for glucose and prolactin is infrequent in children and adolescents initiating antipsychotic therapy. Strategies for physicians, patients, and guardians are needed to overcome the barriers in glucose and prolactin monitoring.

Decreasing Trend in the Use and Long-Term Use of Benzodiazepines Among Young Adults

OBJECTIVE

Patterns of benzodiazepine (BZD) use and long-term use among young adults are not well known. Our aim was to study trends in BZD use and long-term use among 18-25-year-old young adults by gender and active substance in a nationwide retrospective longitudinal register-based setting.

METHODS

All Finns aged 18-25 years with reimbursed purchases of BZDs in 2006-2014 recorded to the Finnish Prescription Register were included. Annual prevalence rates of BZD use and long-term use among young adults were reported overall, according to gender, drug group (anxiolytic or hypnotic), and active substance. Long-term use of BZDs was defined as purchasing ≥180 Defined Daily Doses (DDDs) in at least two drug purchases during a calendar year.

RESULTS

Overall prevalence of BZD use among young adults decreased from 24.0 to 18.8 users per 1000 inhabitants in 2006-2014. Prevalence of long-term use decreased from 5.5 to 3.3 users per 1000 inhabitants. Overall BZD use was higher among females, whereas long-term use was more common among males. Use of anxiolytics was more common than use of hypnotics. Oxazepam, alprazolam, zopiclone, and zolpidem were the most used BZDs, whereas alprazolam and clonazepam were the substances with most long-term use. The use and long-term use of BZDs have decreased annually since 2008 among Finnish young adults. Further research is needed to investigate the reasons behind the decline.

Psychotropic Drug Prescription in Adolescents: A Retrospective Study in a Swiss Psychiatric University Hospital

OBJECTIVES

This retrospective study aims to evaluate off-label prescriptions and administrations of psychotropic medications in adolescents in a university psychiatric hospital in Switzerland.

METHODS

Data were collected during the entire stays from the electronic database for 76 inpatients in 2008 and 76 inpatients in 2014. Data collected included gender, age, psychiatric diagnosis, duration of hospitalization, and psychotropic drug prescriptions and administrations.

RESULTS

A total of 224 psychotropic drugs (mean 2.9 drugs/patient) were prescribed in 2008 and 268 (mean 3.5 drugs/patient) in 2014. Due to the prescriptions of some drugs as required, only 76% of the prescriptions were actually administered in 2008 (mean 2.3 drugs/patient) and 55% in 2014 (mean 1.9 drugs/patient). Antipsychotics were the most frequently prescribed drugs in 2008 (74% of patients) and 2014 (86% of patients). Anxiolytics were also highly prescribed in 2008 (54% of patients) and 2014 (66% of patients), as well as antidepressants in 2008 (30% of patients), but less in 2014 (13% of patients). Overall, 69% of prescriptions were found to be off label in 2008 and 68% in 2014, according to age, diagnosis, dose, or formulation as approved by Swissmedic. The medication classes with the highest rate of off-label prescriptions were antidepressants (100% for both years), antipsychotics (94% in 2008 and 92% in 2014), and hypnotics (67% in 2008 and 100% in 2014). For both study periods, at least one off-label psychotropic drug prescription and administration was recorded in 96% and 79% of the patients, respectively.

CONCLUSION

The high rate of off-label psychotropic drug use strengthens the need for clinical trials to better evaluate the efficacy and safety of these treatments in adolescents.

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.

Intergenerational transmission of depressive symptoms - The role of gender, socioeconomic circumstances, and the accumulation of parental symptoms

BACKGROUND

The relationship between parental and offspring depression is well established. Evidence regarding the significance of gender, socioeconomic circumstances, and the accumulation of parental symptoms in intergenerational transmission is, however, mixed and scarce.

METHODS

Using a 20% random sample of Finns born between 1986 and 1996 (n=138,559), we performed a Cox proportional hazards regression to analyze the incidence of depressive symptoms between ages 15-20 by exposure to maternal and paternal depressive symptoms earlier in life. Depressive symptoms were inferred from antidepressant purchases and/or a diagnosis of depression at outpatient or inpatient health services.

RESULTS

Exposure to maternal depressive symptoms posed an equal risk for girls and boys (hazard ratio, HR, 2.09 vs. 2.28 respectively, p=0.077), whereas the effect of paternal depressive symptoms was weaker for girls (HR 1.77 vs. 2.22, p<0.001). Parental socioeconomic status neither confounded nor moderated these effects. Dual exposure to both maternal and paternal depressive symptoms posed a larger risk than single exposure, and children exposed recurrently at ages 0-5 and 9-14 faced an elevated risk compared with those exposed at only one period.

LIMITATIONS

Since depressive symptoms were inferred from prescription purchases and treatment records, we were unable to observe untreated depression or to determine the underlying condition the antidepressants were prescribed for.

CONCLUSIONS

Our results support the idea that maternal depression affects both genders equally, whereas paternal depression affects girls less than boys. We show that parental depression and low socioeconomic status are mainly independent risk factors of adolescent depressive symptoms and do not cause an interactive effect.

Diagnostic efficiency of the SDQ for parents to identify ADHD in the UK: a ROC analysis

Early, accurate identification of ADHD would improve outcomes while avoiding unnecessary medication exposure for non-ADHD youths, but is challenging, especially in primary care. The aim of this paper is to test the Strengths and Difficulties Questionnaire (SDQ) using a nationally representative sample to develop scoring weights for clinical use. The British Child and Adolescent Mental Health Survey (N = 18,232 youths 5-15 years old) included semi-structured interview DSM-IV diagnoses and parent-rated SDQ scores. Areas under the curve for SDQ subscales were good (0.81) to excellent (0.96) across sex and age groups. Hyperactivity/inattention scale scores of 10+ increased odds of ADHD by 21.3×. For discriminating ADHD from other diagnoses, accuracy was fair (<0.70) to good (0.88); Hyperactivity/inattention scale scores of 10+ increased odds of ADHD by 4.47×. The SDQ is free, easy to score, and provides clinically meaningful changes in odds of ADHD that can guide clinical decision-making in an evidence-based medicine framework.

Nonmedical use of prescription drugs in the European Union

BACKGROUND

Nonmedical prescription drug use (NMPDU) refers to the self-treatment of a medical condition using medication without a prescriber's authorization as well as use to achieve euphoric states. This article reports data from a cross-national investigation of NMPDU in five European Countries, with the aim to understand the prevalence and characteristics of those engaging in NMPDU across the EU.

METHODS

A parallel series of self-administered, cross-sectional, general population surveys were conducted in 2014. Data were collected using multi-stage quota sampling and then weighted using General Exponential Model. A total of 22,070 non-institutionalized participants, aged 12 to 49 years, in 5 countries: Denmark, Germany, Great Britain, Spain, and Sweden. Lifetime and past-year nonmedical use of prescription medications such as stimulants, opioids, and sedatives were ascertained via a modified version of the World Health Organization's Composite International Diagnostic Interview. Information about how the medications were acquired for NMPDU were also collected from the respondent.

RESULTS

Lifetime and past-year prevalence of nonmedical prescription drug use was estimated for opioids (13.5 and 5.0 %), sedatives (10.9 and 5.8 %), and stimulants (7.0 and 2.8 %). Germany exhibited the lowest levels of NMPDU, with Great Britain, Spain, and Sweden having the highest levels. Mental and sexual health risk factors were associated with an increased likelihood of past-year nonmedical prescription drug use. Among past-year users, about 32, 28, and 52 % of opioid, sedative, and stimulant nonmedical users, respectively, also consumed illicit drugs. Social sources (sharing by friends/family) were the most commonly endorsed methods of acquisition, ranging from 44 % (opioids) to 62 % (sedatives). Of interest is that Internet pharmacies were a common source of medications for opioids (4.1 %), stimulants (7.6 %), and sedatives (2.7 %).

CONCLUSIONS

Nonmedical prescription drug use was reported across the five EU countries we studied, with opioids and sedatives being the most prevalent classes of prescription psychotherapeutics. International collaborations are needed for continued monitoring and intervention efforts to target population subgroups at greatest risk for NMDU.

Latest trends in ADHD drug prescribing patterns in children in the UK: prevalence, incidence and persistence

OBJECTIVES

To investigate attention deficit and hyperactivity disorder (ADHD) drug prescribing in children under 16 years old in the UK between 1992 and 2013.

METHODS

All patients under 16 registered in the Clinical Practice Research Datalink (CPRD) with a minimum of 1 year of observation time and who received at least one prescription of any ADHD drug between 1 January 1992 and 31 December 2013.Trends in prevalence and incidence of use of ADHD drugs in children were calculated between 1995 and 2013 and persistence in new users was estimated.

RESULTS

The prevalence of ADHD drug use in children under 16 increased 34-fold overall, rising from 1.5 95% CI (1.1 to 2.0) per 10 000 children in 1995 to 50.7 95% CI (49.2 to 52.1) per 10 000 children in 2008 then stabilising to 51.1 95% CI (49.7 to 52.6) per 10 000 children in 2013. The rate of new users increased eightfold reaching 10.2 95% CI (9.5 to 10.9) per 10 000 children in 2007 then decreasing to 9.1 95% CI (8.5 to 9.7) per 10 000 children in 2013. Although prevalence and incidence increased rather steeply after 1995, this trend seems to halt from 2008 onwards. We identified that 77%, 95% CI (76% to 78%) of children were still under treatment after 1 year and 60% 95% CI (59% to 61%) after 2 years.

CONCLUSIONS

There was a marked increase in ADHD drug use among children in the UK from 1992 until around 2008, with stable levels of use since then. UK children show relatively long persistence of treatment with ADHD medications compared to other countries.

Off-label prescribing of psychotropic drugs in a Danish child and adolescent psychiatric outpatient clinic

This study aimed to describe the level of off-label treatment with psychotropic drugs at a child and adolescent psychiatric outpatient clinic in Denmark. We performed a cross-sectional study assessing records on patients treated with medicine at two outpatient clinics at the child and adolescent psychiatric ward, on 1 day in 2014. Prescriptions of drugs from ATC group N05-N06 were classified according to label status. Six hundred and fifteen drug prescriptions distributed on nine different drugs were prescribed to 503 children eligible for this study. Overall results showed that 170 of the 615 prescriptions were off-label, which corresponds to 27.6 %. Attention deficit hyperkinetic disorder (ADHD) drugs were prescribed 450 times (73.2 %) of which 11 prescriptions were off-label (2.4 %). Other psychotropic drugs comprised 165 (26.8 %) prescriptions and of these 159 (96.4 %) were off-label. With 106 prescriptions, melatonin was the most prescribed of these drugs; all prescriptions were off-label. The main reasons for classifying prescriptions as off-label were age and indication of treatment. This cross-sectional study reveals that medical treatment of children with other psychotropic drugs than ADHD drugs is usually off-label. ADHD drugs were, as the only drug group, primarily prescribed on-label. Although off-label prescription may be rational and even evidence based, the responsibility in case of, e.g. adverse drug reactions is a challenge, and clinical trials in children should be incited.

Drug use in French children: a population-based study

BACKGROUND AND OBJECTIVE

To provide an overview of drug use in outpatient children in France, a population-based study using a national reimbursement claims database representative of 90% of the French population was conducted.

DESIGN

Cross-sectional study performed between January and December 2011 using the EGB database (Echantillon Généraliste de Bénéficiaires), a 1/97th sample of the national healthcare insurance system beneficiaries. Drug use in children <18 years old was estimated through reimbursements for prescribed drugs excluding vaccines. Prevalences of use were calculated for different levels of the Anatomical Therapeutic Chemical classification by considering as users children who had at least one reimbursement during the study period.

RESULTS

In 2011, 133,800 children were included in the study. The overall prevalence of drug use was 84% and the median number of different drugs per child was 5. Drug use was greatest in children aged <2 years. The most widely used drugs were paracetamol, systemic anti-infectives, nasal corticosteroids and decongestants, and anti-histamines. 21% children <2 years received domperidone.

CONCLUSIONS

There is widespread use of medicines that are unlikely to be effective and may have significant toxicity in French children. Irrational use of medicines appears to be greatest in children aged 5 years and under.

Paediatric Off-Label Use of Melatonin--A Register Linkage Study between the Norwegian Prescription Database and Patient Register

The aims were, for the entire Norwegian population aged 4-17 years, to study the prevalence of melatonin use during 2004-2012, recurrent use in incident users and psychiatric and neurological morbidity in recurrent users. Data on dispensed melatonin were retrieved from the Norwegian Prescription Database and linked to diagnostic data from the Norwegian Patient Register. Outcome measures were the following: 1-year prevalence of use, proportion of recurrent use (use over three consecutive 365-day periods among incident users in 2009) and annual number of milligrams and number of prescriptions dispensed in recurrent users. The prevalence of registered ICD-10 diagnoses during the period of 2008-2012 was given for the recurrent users. The prevalence of melatonin use increased annually in both genders during 2004-2012 (boys: 3.4-11.0 per 1000; girls: 1.5-7.7 per 1000). Twenty-nine per cent of boys and 23% of girls were recurrent melatonin users, with highest level of recurrent use among the youngest (aged 4-8 years; boys: 47%, girls: 42%). In the third year, the median annual amount of melatonin dispensed was 1080 (IQR 586-1800) milligrams in boys and 900 (IQR 402-1620) milligrams in girls. Among recurrent users, 91% had a diagnosis of either psychiatric (84%) or neurological (32%) disorder. Off-label recurrent use of melatonin seems to have acquired a role mainly in treating secondary sleep problems in children and adolescents with psychiatric and neurological disorders. Once melatonin has been started, a large proportion of patients continue for at least 3 years, in doses corresponding to daily use in the majority.

Psychotropic medication use in French children and adolescents

OBJECTIVE

The purpose of this study was to describe the patterns of psychotropic drug use in a large representative population of children and adolescents drawn from the French National Health Insurance databank.

METHODS

Data were drawn from a sample of 1% of the beneficiaries of the French national health insurance, selecting those 0-17 years old in 2010 (n=128,298). In addition to age and gender, data included the identification number of each drug allowing a European Pharmaceutical Marketing Research Association (EphMRA) classification, as well as the type of the prescriber.

RESULTS

Overall, 2.5% of children and adolescents had been prescribed psychotropic medication. A majority were prescribed anxiolytics (1.9%), followed by antidepressants (0.3%), antipsychotics (0.3%), and stimulants (0.2%). Between the ages of 15 and 17, 6.1% of girls were prescribed anxiolytics and 1.1% were prescribed antidepressants. For boys, the anxiolytics remained the most prescribed psychotropic medication; however, between the ages of 11 and 14, and between the ages of 15 and 17 they received more antipsychotics (0.7% and 0.8%) and between the ages of 6 and 10, and between the ages of 11 and 14 (0.7% and 0.6%), they were prescribed more stimulants than were girls. Among those who received a prescription, a majority of youth (84.6%) received only one class of drugs, and general practitioners were found to be prescribing most of these prescriptions (81.7%).

CONCLUSIONS

The prevalence of psychotropic drug use in France is similar to that of the Netherlands and much lower than what is observed in the United States. Stimulants are less frequently prescribed in France than in other European countries, but anxiolytics are prescribed considerably more in France than in any other country.

Annual research review: Secular trends in child and adolescent mental health

BACKGROUND

Child and adolescent mental health problems are common, associated with wide-ranging functional impairments, and show substantial continuities into adult life. It is therefore important to understand the extent to which the prevalence of mental health problems has changed over time, and to identify reasons behind any trends in mental health.

SCOPE AND METHODOLOGY

This review evaluates evidence on whether the population prevalence of child and adolescent mental health problems has changed. The primary focus of the review is on epidemiological cross-cohort comparisons identified by a systematic search of the literature (using the Web of Knowledge database).

FINDINGS

Clinical diagnosis and treatment of child and adolescent psychiatric disorders increased over recent decades. Epidemiological comparisons of unselected population cohorts using equivalent assessments of mental health have found little evidence of an increased rate of ADHD, but cross-cohort comparisons of rates of ASD are lacking at this time. Findings do suggest substantial secular change in emotional problems and antisocial behaviour in high-income countries, including periods of increase and decrease in symptom prevalence. Evidence from low- and middle-income countries is very limited. Possible explanations for trends in child and adolescent mental health are discussed. The review also addresses how cross-cohort comparisons can provide valuable complementary information on the aetiology of mental illness.

Trends in parent- and teacher-rated emotional, conduct and ADHD problems and their impact in prepubertal children in Great Britain: 1999-2008

BACKGROUND

Evidence from Western countries indicates marked increases in diagnosis and treatment of childhood psychiatric disorders in recent years. These could reflect changes in prevalence of mental health problems, changes in their impact or increased clinical recognition and help-seeking. Epidemiological cross-cohort comparisons are required to test possible changes in prevalence, but are lacking for pre-adolescent children in Great Britain.

METHODS

Parent and teacher Strength and Difficulties Questionnaire (SDQ) ratings were used to compare rates of emotional, conduct and hyperactivity problems in 7-year-old children across three nationally representative British samples assessed in 1999 (n = 1033), 2004 (n = 648) and 2008 (n = 13,857). The SDQ impact supplement was used to assess associated distress, social, and educational impairment. Stratified analyses examined trends by gender and socio-economic group.

RESULTS

There was a decline in mean problem scores and a fall in the percentages scoring in the 'abnormal' range for all symptom types across the period of study. This decline was observed for all demographic groups, for parent and teacher reports, and was more marked for boys than girls. Both parent- and teacher-rated impact scores differed across the three cohorts for boys. Teacher-rated impact scores differed across cohorts for girls.

CONCLUSIONS

The first decade of the 21st Century saw a reduction in perceived levels of emotional and behaviour problems in pre-adolescent children in Great Britain. The threshold at which mental health problems have an impact on children's distress and classroom learning has changed over time. Continued monitoring of child mental health remains a priority.

Antidepressant prescribing in five European countries: application of common definitions to assess the prevalence, clinical observations, and methodological implications

PURPOSE

Drug utilization studies have applied different methods to various data types to describe medication use, which hampers comparisons across populations. The aim of this study was to describe the time trends in antidepressant prescribing in the last decade and the variation in the prevalence, calculated in a uniform manner, in seven European electronic healthcare databases.

METHODS

Annual prevalence per 10,000 person-years (PYs) was calculated for 2001-2009 in databases from Spain, Germany, Denmark, the United Kingdom (UK), and the Netherlands. Prevalence data were stratified according to age, sex, antidepressant type (selective serotonin re-uptake inhibitors [SSRIs] or tricyclic antidepressants [TCAs]) and major indications.

RESULTS

The age- and sex-standardized prevalence was lowest in the two Dutch (391 and 429 users per 10,000 PYs) and highest in the two UK (913 and 936 users per 10,000 PYs) populations in 2008. The prevalence in the Danish, German, and Spanish populations was 637, 618, and 644 users per 10,000 PY respectively. Antidepressants were prescribed most often in 20- to 60-year-olds in the two UK populations compared with the others. SSRIs were prescribed more often than TCAs in all except the German population. In the majority of countries we observed an increasing trend of antidepressant prescribing over time. Two different methods identifying recorded indications yielded different ranges of proportions of patients recorded with the specific indication (15-57% and 39-69% for depression respectively).

CONCLUSION

Despite applying uniform methods, variations in the prevalence of antidepressant prescribing were obvious in the different populations. Database characteristics and clinical factors may both explain these variations.

Alternative national guidelines for treating attention and depression problems in children: comparison of treatment approaches and prescribing rates in the United Kingdom and United States

The use of psychotropic medications for children and adolescents with attention and depression problems continues to generate both attention in the news media and controversy within the field. Given that the United Kingdom has recently issued guidelines for its national health service that differ substantially from those in the United States, the time is ripe to reexamine the evidence. The purpose of this article is to describe the UK's new "stepped care" guidelines for treating attention and depression problems in children and to compare them to the US guidelines issued by the American Academy of Pediatrics and the American Academy of Child and Adolescent Psychiatry. Our findings are that, despite many similarities, the UK guidelines are generally more conservative in their recommendations for medication use, especially for children experiencing only moderate impairment. Our article also compares prescription and diagnosis rates in the UK and the US, and reports evidence for lower rates of prescribing in the UK, despite some evidence that the rates of problems may not differ substantially. We conclude by noting that the existence of an alternative standard provides validation for clinicians or families who prefer to take a more conservative approach to medication use. The two different approaches to care also provide a valuable opportunity for research to determine whether the approaches result in different treatment outcomes.

Second-generation antipsychotics cause a rapid switch to fat oxidation that is required for survival in C57BL/6J mice

Some second-generation antipsychotics (SGAs) increase insulin resistance and fat oxidation, but counter intuitively they do not activate lipolysis. This seems unsustainable for meeting energy demands. Here, we measured dose-dependent effects of SGAs on rates of oxygen consumption (VO2), respiratory exchange ratio (RER), and physical activity in C57BL/6J mice. The role of H1-histamine receptors and consequences of blocking fat oxidation were also examined. Olanzapine, risperidone, and clozapine (2.5-10mg/kg) elicited rapid drops in dark-cycle RER (~0.7) within minutes, whereas aripiprazole exerted only modest changes. Higher doses of olanzapine decreased VO2, and this was associated with accumulation of glucose in plasma. Clozapine and risperidone also lowered VO2, in contrast to aripiprazole, whereas all decreased physical activity. Astemizole and terfenadine had no significant effects on RER, VO2, or physical activity. The VO2 and RER effects appear independent of sedation/physical activity or H1-receptors. CPT-1 inhibitors can enhance muscle glucose utilization and prevent fat oxidation. However, after etomoxir (2 × 30 mg/kg), a low dose of olanzapine that did not significantly affect VO2 by itself caused precipitous drops in VO2 and body temperature, leading to death within hours or a moribund state requiring euthanasia. One 30 mg/kg dose of either etomoxir or 2-tetradecylglycidate followed by olanzapine, risperidone, or clozapine, but not aripiprazole, dramatically lowered VO2 and body temperature. Thus, mice treated with some SGAs shift their fuel utilization to mostly fat but are unable to either switch back to glucose or meet their energy demands when either higher doses are used or when fat oxidation is blocked.

Trends, correlates, and disease patterns of antipsychotic use among children and adolescents in Taiwan

PURPOSE

We used Taiwan's population-based National Health Insurance database to investigate the trends, correlates, and disease patterns of antipsychotic use among children and adolescents.

METHODS

The National Health Research Institutes provided a database of 1,000,000 random subjects for study. We chose subjects who were aged 18 years or younger during 1997-2005. In this sample, subjects who were given at least one antipsychotic prescription, including first-generation antipsychotics (FGAs) or second-generation antipsychotics (SGAs), were identified. Trends, prevalence, and associated factors of antipsychotic use were determined. The proportion of antipsychotic use for psychiatric and medical disorders was also analyzed.

RESULTS

The 1-year prevalence of SGA use increased from 0.00 % in 1997 to 0.09 % in 2005, whereas the 1-year prevalence of FGA use ranged from 2.24 to 3.43 % during this same period, with no significant change. Age and male gender were associated with higher SGA use. Among SGA users, the greatest proportion suffered from psychiatric disorders, including tics, hyperkinetic syndrome of childhood, schizophrenia, affective disorders, and autism. Among FGA users, a larger proportion was for medical conditions, including diseases of the digestive and respiratory systems.

CONCLUSION

The prevalence of pediatric SGA use increased greatly from 1997 to 2005. Among pediatric subjects using antipsychotics, SGAs were mostly used for psychiatric disorders, whereas FGAs were mostly prescribed for medical conditions. Future research will focus on indication, dosage, frequency, duration, adverse effects, and off-label use of antipsychotics in the pediatric population.

Mapping developmental trajectories of attention and working memory in fragile X syndrome: Developmental freeze or developmental change?

Fragile X syndrome (FXS) has a characteristic cognitive “signature” that by late childhood includes core weaknesses in attention and working memory (WM), but their earlier developmental trajectories remain uncharted. Using a combined cross-sectional and prospective longitudinal design, we tested whether early profiles of attention and WM impairment in FXS indicate developmental freeze or developmental change. In Study 1, 26 young boys with FXS and 55 typically developing (TD) boys completed two experimental paradigms designed to assess cognitive aspects of attention and WM, in addition to behavioral indices of inattention and hyperactivity. Study 2 mapped longitudinal changes in 21 children with FXS and 21 TD children. In Study 1, significant weaknesses emerged for boys with FXS, with no substantial improvement over chronological age. Mapping performance against mental age level revealed delay, but it also yielded a similar attention and WM profile to TD boys. In Study 2, longitudinal improvements for boys with FXS paralleled those in TD children. In conclusion, cognitive attention and WM, although delayed in FXS, reveal developmental change, rather than “arrest.” Our findings underscore the need for going beyond cross-sectional group comparisons and gross behavioral indices to map cognitive changes longitudinally in developmental disorders.

An update on antidepressant use and suicidality in pediatric depression

INTRODUCTION

In 2003, public health advisories in North America and Europe regarding suicidality associated with selective serotonin reuptake inhibitors (SSRIs) led to the addition of black box warnings to antidepressant package inserts in 2004. Subsequently, a series of events appeared to result from these regulatory actions.

AREAS COVERED

This review provides an overview of the temporal associations of regulatory agencies' actions in North America and Europe with rates of depression diagnoses, pediatric antidepressant prescription rates, follow-up visits to physicians prescribing antidepressants, and rates of completed suicide and suicidal ideation in children and adolescents. In addition, evidence-based predictors of suicidal behavior and suicide risk, as provided by large, multisite studies of depressed children and adolescents, are outlined. Finally, this review considers key advancements in the study of young patients at risk for suicide and describes innovations in current research methodology, to more accurately identify suicidality and the relationship to antidepressant use within this vulnerable patient population.

EXPERT OPINION

Evaluating the role of antidepressants in those youths who do not respond to evidence-based psychotherapeutic interventions may be a useful future research direction. Until more data are available, however, closely monitored antidepressant treatment in combination with CBT may provide the most benefit.

Hypnotic drug use among 0–17 year olds during 2004–2011: A nationwide prescription database study

Aims: To (a) describe the prevalence, trend, and amount of hypnotic drug use, (b) determine the prevalence of chronic diseases among hypnotic drug users, and (c) determine levels of recurrent hypnotic drug use (2007–2011), among 0–17 year old Norwegians. Methods: Data were obtained from the nationwide Norwegian Prescription Database (NorPD) in the period 2004–2011. Results: Hypnotic drug use in 0–17 year olds increased during the period, from 8.9 to 12.3 per 1000, mainly owing to doubling of melatonin use. Hypnotic drug use peaked at 15 per 1000 among those aged 1–2 years. Melatonin use increased steadily from 6 to 12 years of age, most pronounced in males. Among females, hypnotic drug use increased threefold from 13 to17 years of age. Melatonin was dispensed in the highest annual amount of all hypnotic drugs; accounting up to a median of 360 defined daily doses in 9–13 year old boys. A total of 62% and 52% of all male and female hypnotic drug users were co-medicated with reimbursable drugs for chronic diseases. Levels of recurrent use (2007–2011) were 12% in boys and 8% in girls, of whom 76–77% were co-medicated with drugs reimbursed for chronic diseases. Conclusions: There is a trend of increasing use of hypnotic drugs among 0–17 year olds, mainly owing to increasing use of melatonin, used in high amounts. Still, melatonin is not recommended in Norway for use in this age group because of insufficient data on safety and efficacy. A threefold increase in hypnotic drugs among females from 13 to 17 years of age warrants attention.

Increase in psychotropic drug use between 2006 and 2010 among adolescents in Norway: a nationwide prescription database study

Background

The purposes of this study were to investigate the prevalence of psychotropic (hypnotic, antidepressant, and anxiolytic) drug use among adolescents aged 15–16 years during the period 2006–2010 according to gender and subcategories of psychotropics, and to study psychotropic drug use over the period 2007–2010 among incident users in 2007.

Methods

This was a one-year prevalence and follow-up study based on information retrieved from the nationwide Norwegian prescription database for the period 2006–2010. The study population consisted of adolescents aged 15–16 years who had filled at least one prescription for a psychotropic drug in the study period. The main outcome measures were filling of hypnotic, antidepressant, and/or anxiolytic drug prescriptions.

Results

Overall use of psychotropic drugs increased from 13.9 to 21.5 per 1000 among boys and from 19.7 to 24.7 per 1000 among girls during the 2006– 2010 period. Hypnotic drugs, and melatonin in particular, accounted for most of the increase. For melatonin, the annual median amount dispensed was 180 defined daily doses through the period until 2010, at which time it decreased to 90 defined daily doses. In total, 16.4% of all incident psychotropic drug users in 2007 were still having prescriptions dispensed in 2010.

Conclusion

This study shows an increase in hypnotic drugs dispensed for adolescents in Norway, mainly attributable to the increasing use of melatonin. The amount of melatonin dispensed indicates more than sporadic use over longer periods, despite melatonin only being licensed in Norway for use in insomnia for individuals aged 55 years or older.

Use of psychotropic drugs, systemic antihistamines and medications for cough in 6-year-old children: a survey in the Bas-Rhin Region, France

PURPOSE

The use of drugs in France is among the highest in developed countries. Among them, psychotropic medication in children has always been a matter of concern. Furthermore, on the basis of concerns about safety and efficacy, international authorities have either advised against the use of cough and cold medication or considered such an action. This survey aims to assess the prevalence of use of psychotropic drugs, antihistamines and medications for cough as well as parents' knowledge about the drugs used in 2009.

METHODS

The study is based on a representative sample of 6-year-old children who were in kindergarten in 2009. School physicians asked their parents to answer a standardized questionnaire. Data were collected about the child, his or her family, and the consumption of psychotropic drugs, antihistamines, and medications for cough in the past 12 months. The Anatomical Therapeutic Chemical (ATC) classification system was used to classify the drugs used.

RESULTS

The data from 5707 children were analyzed. The proportion of children who consumed at least one psychotropic drug was 0.68% (ATC code N). Antihistamines for systemic use were by far the most frequently consumed drugs (ATC code R06), with a prevalence of 17.54%. The great majority of antihistamines for systemic use were meant to treat cough, not insomnia or agitation.

CONCLUSION

The use of psychotropic drugs was low in 2009 in the French region of Bas-Rhin. The promotion of alternatives to antihistamines for systemic use to treat cough should nevertheless be strengthened.

A population-based study of stimulant drug treatment of ADHD and academic progress in children

OBJECTIVE

We evaluated the hypothesis that later start of stimulant treatment of attention-deficit/hyperactivity disorder adversely affects academic progress in mathematics and language arts among 9- to 12-year-old children.

METHODS

We linked nationwide data from the Icelandic Medicines Registry and the Database of National Scholastic Examinations. The study population comprised 11,872 children born in 1994-1996 who took standardized tests in both fourth and seventh grade. We estimated the probability of academic decline (drop of ≥ 5.0 percentile points) according to drug exposure and timing of treatment start between examinations. To limit confounding by indication, we concentrated on children who started treatment either early or later, but at some point between fourth-grade and seventh-grade standardized tests.

RESULTS

In contrast with nonmedicated children, children starting stimulant treatment between their fourth- and seventh-grade tests were more likely to decline in test performance. The crude probability of academic decline was 72.9% in mathematics and 42.9% in language arts for children with a treatment start 25 to 36 months after the fourth-grade test. Compared with those starting treatment earlier (≤ 12 months after tests), the multivariable adjusted risk ratio (RR) for decline was 1.7 (95% confidence interval [CI]: 1.2-2.4) in mathematics and 1.1 (95% CI: 0.7-1.8) in language arts. The adjusted RR of mathematics decline with later treatment was higher among girls (RR, 2.7; 95% CI: 1.2-6.0) than boys (RR, 1.4; 95% CI: 0.9-2.0).

CONCLUSIONS

Later start of stimulant drug treatment of attention-deficit/hyperactivity disorder is associated with academic decline in mathematics.

Mental distress and subsequent use of psychotropic drugs among adolescents-a prospective register linkage study

PURPOSE

To investigate the association between mental distress, other factors, and subsequent use of psychotropic drugs in adolescents aged 15-16 years.

METHODS

This study is based on information retrieved from the Norwegian Youth Health Surveys (2000-2003) and linked to prescription data from the Norwegian Prescription Database (2004-2009). The study population included 11,620 adolescents aged 15-16 (87% response rate) years. Self-reported mental distress (Hopkins Symptom Checklist-10 score 1.85) was recorded along with health and lifestyle habits, education plans, and family economics. Incident psychotropic drug use (outcome measure) was defined ≥1 prescriptions of one of the following psychotropic drugs: anxiolytics, hypnotics, antidepressants, or phenothiazines registered in the Norwegian Prescription Database.

RESULTS

Overall, 15.5% of the adolescents reported mental distress, 75% of them were girls. For both genders, incident psychotropic use was significantly higher among those reporting mental distresses at baseline, compared with the rest of the participants. The highest psychotropic drug use was observed among mentally distressed girls (27.7%). Mental distress was significantly associated with incident use of psychotropic drugs (odds ratio: 2.25, 95% confidence interval: 1.97-2.55). After adjustment for confounding factors and inclusion of potential mediating factors, the odds ratio attenuated to 1.59 (95% confidence interval: 1.35-1.86).

CONCLUSIONS

The prevalence of mental distress among adolescents may have consequences for health promotion. Public health nurses in Norway, working in health centers and schools, have a responsibility to promote health and prevent health problems. They have the opportunity and a responsibility to identify vulnerable young people.

Does attention constrain developmental trajectories in fragile x syndrome? A 3-year prospective longitudinal study

Basic attentional processes and their impact on developmental trajectories in fragile X syndrome were assessed in a 3-year prospective study. Although fragile X syndrome is a monogenic X-linked disorder, there is striking variability in outcomes even in young boys with the condition. Attention is a key factor constraining interactions with the environment, so it is a perfect candidate to predict trajectories in cognitive and behavioral outcomes. In this study, 48 boys with fragile X syndrome were assessed 3 times over 24 months. Although nonverbal IQ declined, there were significant improvements in nonverbal growth scores and in cognitive attention. In contrast, behavioral difficulties (i.e., autistic symptomatology, hyperactivity-inattention) remained stable over this time frame. Attentional markers in the visual and auditory modalities predicted intellectual abilities and classroom behavior, whereas auditory markers alone predicted autistic symptomatology.

Prevalence of prescribed attention-deficit hyperactivity disorder medications and diagnosis among Canadian preschoolers and school-age children: 1994-2007

OBJECTIVE

To describe trends in the prevalence of prescribed attention-deficit hyperactivity disorder (ADHD) medication by Canadian preschoolers and school-age children and to compare these with trends in the prevalence of the ADHD diagnosis between 1994 and 2007.

METHODS

Subjects participated in the National Longitudinal Survey on Children and Youth, a Canadian prospective survey collecting data biennially. Three cross-sectional samples of nonreferred children, aged 3 to 9 years and representative of Canadian children for 1994-1995 (n = 12 595), 2000-2001 (n = 13 904), and 2006-2007 (n = 14 655), were selected for the analyses. Information on prescribed medications and ADHD diagnosis was reported by each child's parents. Prevalence was estimated at each cycle, taking the child's age and sex into account.

RESULTS

The estimated prevalence of prescribed medications and ADHD diagnosis in Canada was generally low (less than 3%), but higher for boys (less than 4%) and school-age children (less than 5%). Preschoolers' prevalence of both prescribed medications and ADHD diagnosis stayed stable between 1994 and 2007 (1% or less), while that of school-age children increased nearly 2-fold. Boys' prevalence was higher than that of girls, but girls show the steepest increase over time, up to 2.1-fold. The association between prescribed medications and ADHD diagnosis has strengthened during the 2000s: a greater number of medications were used for children with ADHD (from 43% in 2000 to 59% in 2007) while off-label use of prescribed medications decreased among school-age children.

CONCLUSIONS

The upward trend in the prevalence of prescribed ADHD medications and ADHD diagnosis currently observed in contemporary societies is also occurring in Canada, except with preschoolers.

Ten years of antipsychotic prescribing to children: a Canadian population-based study

OBJECTIVE

To report the prescribing of antipsychotics to the youth population of the Canadian province of Manitoba during the course of a decade.

METHODS

Use of antipsychotics in children and adolescents (aged 18 years or younger) was described using data collected from the administrative health databases of Manitoba Health and the Statistics Canada census between the fiscal years of 1999 and 2008.

RESULTS

The prevalence of antipsychotic use in this segment of the population increased with the introduction of the second-generation antipsychotics (SGAs) from 1.9 per 1000 in 1999 to 7.4 per 1000 in 2008. The male-to-female antipsychotic usage ratio increased from 1.9 to 2.7 as the male youth population represented the fastest-growing subgroup of antipsychotic users in the entire population of Manitoba. The total number of prescriptions also increased significantly despite the lack of approved indications in this population. Proportion of use remained equally split between high- and low-income users. More than 70% of antipsychotic prescriptions to children and adolescents were written by general practitioners. The most common diagnoses linked to antipsychotic use were attention-deficit hyperactivity disorder and conduct disorders. Use of antipsychotics in combination with methylphenidate increased from 13% to 43%.

CONCLUSION

Extensive off-label use of SGAs has been observed in the youth population of Manitoba for treatment of aggressive behaviours across a range of diagnoses. It is important to monitor antipsychotic prescribing to children as more reports of significant adverse events associated with antipsychotics become available.

Antidepressants and adolescent brain development

Despite being a first-line treatment for adolescent depression and anxiety, antidepressant drugs appear to have questionable efficacy and carry an increased risk of adverse effects in this population. The neural mechanisms underlying this phenomenon are currently unknown. Recent research into the neural effects of alcohol and recreational drugs suggests that the developmental trajectory of the adolescent brain may be particularly vulnerable to pharmacological disturbance. It is therefore important to consider whether prescription psychotropic drugs may have analogous effects. This article reviews the contribution of recent preclinical, clinical and pharmacogenetic literature to current knowledge on the short-term and enduring neural effects of antidepressants on the adolescent brain, with a particular focus on the major neurotransmitter systems and neuroplasticity.

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

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

OBJECTIVE

To compare national use of attention-deficit/hyperactivity disorder (ADHD) drugs between five Nordic countries.

METHOD

A population-based drug utilisation study based on nationwide prescription databases, covering in total 24 919 145 individuals in 2007. ADHD drugs defined according to the World Health Organization Anatomic Therapeutic Chemical classification system as centrally acting sympathomimetics (N06BA).

RESULTS

The 2007 prevalence of ADHD drug use among the total Nordic population was 2.76 per 1000 inhabitants, varying from 1.23 per 1000 in Finland to 12.46 per 1000 in Iceland. Adjusting for age, Icelanders were nearly five times more likely than Swedes to have used ADHD drugs (Prev.Ratio = 4.53, 95% CI: 4.38-4.69). Prevalence among boys (age 7-15) was fourfold the prevalence among girls (Prev.Ratio = 4.28, 95% CI: 3.70-4.96). The gender ratio was diminished among adults (age 21 +) (Prev.Ratio = 1.24, CI: 1.21-1.27).

CONCLUSION

A considerable national variation in use of ADHD drugs exists between the Nordic countries.

Dispensing of prescribed analgesics in Norway among young people with foreign-or Norwegian-born parents

Purpose To examine and compare dispensing of prescribed analgesics between young people with parents from countries with a Muslim majority and those with parents born in Norway. Methods Our study-population constituted 11,542 adolescents from the Norwegian Youth Health Surveys conducted in 2000-2003. Users and non-users of prescribed analgesics at baseline were analysed separately. Self-reported information on their parents' birth country was used to classify them into one of the three predefined groups: Norway, countries with a Muslim majority or others. To study and compare dispensing of prescribed analgesics, data from the youth surveys were linked to the Norwegian Prescription Database (NorPD) 2004-2007. Dispensed analgesics studied were antiinflammatory and antirheumatic products (non-steroid), opioids and other analgesics and antipyretics. Results Among non-users of prescribed analgesics at baseline, 34% of all males with parents born in Norway received prescribed analgesics at least once during 2004-2007, compared to 36% in the group with parents from countries with a Muslim majority. The proportions of females receiving prescribed analgesics were about 44% in both of the two previously mentioned groups. Among users of prescribed analgesics at baseline, the proportion of individuals who were dispensed prescribed analgesics in 2004-2007 was generally higher than for those that were non-users at baseline. Both males and females with parents from countries with a Muslim majority reported more pain compared to those with parents born in Norway. No statistical differences were detected between participants with parents from countries with a Muslim majority compared to those with parents born in Norway in terms of prescribed analgesics dispensed or total amount of analgesics dispensed in 2004-2007. For the dispensing of all analgesics in 2004-2007 the adjusted OR for having parents from countries with a Muslim majority compared to parents born in Norway was 1.02 (0.87-1.21) among non-users of prescribed analgesics at baseline and 0.82 (0.57-1.16) among users. Conclusions There were no differences in the dispensing of prescribed analgesics between young people with parents born in countries with a Muslim majority and those with parents born in Norway. Nor did the amount of prescribed analgesics differ between these groups.

The Shanghai Changfeng Study: a community-based prospective cohort study of chronic diseases among middle-aged and elderly: objectives and design

The Shanghai Changfeng Study is a community-based prospective cohort study of chronic diseases ongoing since February 2009 in Shanghai, China. The study focuses on multiple chronic diseases, including obesity and metabolic syndrome, diabetes, osteoporosis, liver diseases, cardiovascular diseases and neurologic diseases. 15,000 subjects of 40 years or over are planned to be recruited. The rationale, objectives and design of this study are described in this paper.

Analysis of individual drug use as a time-varying determinant of exposure in prospective population-based cohort studies

In pharmaco-epidemiology, the use of drugs is the determinant of interest when studying exposure-outcome associations. The increased availability of computerized information about drug use on an individual basis has greatly facilitated analyses of drug effects on a population-based scale. It seems likely that many negative findings in the early days of pharmaco-epidemiology can be explained by non-differential misclassification because of too simple (yes/no) exposure measures. In this paper, the authors discuss the importance of an adequate definition of drug exposure in pharmaco-epidemiological research and how this time-varying determinant can be analyzed in cohort studies. To reduce the risk of non-differential misclassification, a precise definition of exposure is mandatory and it is important to distinguish the complete follow-up period of a population into mutually exclusive episodes of non-use, past use and current use for each individual. By analyzing exposure to drugs as a time-dependent variable in a Cox regression model, cohort studies with complete coverage of all filled prescriptions can provide us with valid and precise risk estimates of drug-outcome associations. However, such estimates may be biased in the presence of time-dependent confounders which are themselves affected by prior exposure.