March 5, 2012
Hyperactivity: Increased Prevalence Of Children With ADHD And The Use Of Stimulants
A new study from the UniversitÃ© de MontrÃ©al shows an increase in prevalence of Canadian children diagnosed with attention-deficit hyperactivity disorder (ADHD) and in the use of medications associated with ADHD in school-age children.
The study, Prevalence of Prescribed Attention-Deficit Hyperactivity Disorder Medications and Diagnosis Among Canadian Preschoolers and School-Age Children: 1994—2007, was conducted by the doctoral student in sociology, Marie-Christine Brault, under the supervision of Professor Ãric Lacourse of the Research Unit on Children's Psychosocial Maladjustment (GRIP) at the UniversitÃ© de MontrÃ©al. It was published in the most recent issue of The Canadian Journal of Psychiatry.
Increased use of medications
In 2000, 43% of Canadian children with ADHD were taking medications, while in 2007, the number was 59%. The study's data comes from a sample of Canadian children aged 3 to 9 who participated in the National Longitudinal Survey on Children and Youth.
“The increased use of medications by children with ADHD in Canada is a reflection of the global trend, says Marie-Christine Brault, lead author of the study. Consumption of drugs like Ritalin, to name but one, has more than doubled since 1994, when it was 1.3%.”
The study also showed a decrease in the off-label use of ADHD medications, except for preschoolers, for whom there was a slight increase. “Some doctors may be prescribing ADHD medications to treat other problems such as oppositional defiant disorder or conduct disorder. This may explain the slight increase,” says Marie-Christine Brault.
Boys take more medications
According to the results of the study, boys' prevalence of medication use, at around 3%, was higher than that of girls; however, girls showed the steepest increase over time, up to 2.1-fold. This rise occurred essentially in the 1990s, while for boys, it was observed in the 2000s. 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.
Increased use of medications among school-age children
Preschoolers' prevalence of both ADHD diagnosis and prescribed medications stayed stable between 1994 and 2007 (1% or less), while that of school-age children increased nearly two-fold, suggesting, for the authors, that school environment plays a role in the increased use of medications. Boys' prevalence was higher than that of girls, but girls show the steepest increase over time, up to 2.1-fold.
“Can the upward trend in ADHD diagnoses explain the increased use of medications? Or is the opposite true?” asks Marie-Christine Brault. “Both hypotheses are plausible. Identifying the factors associated with these trends is the only way to answer the question: Are children with ADHD over-medicated?”
The question is not banal, because attention-deficit hyperactivity disorder is the most common mental illness in children.
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