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Why are so many youths with ADHD prescribed antipsychotic drugs?

A new study finds that 12 per cent Ontario youth diagnosed with ADHD are being prescribed antipsychotic drugs, even though there is little evidence of them having positive benefits for youth with ADHD.

The study, conducted by the Institute for Clinical Evaluative Sciences in Toronto, looked at medical records for 250,000 youths in Ontario aged one to 24 years and reviewed a random sample of 10,000 of them for the prevalence of ADHD and the various treatment options pursued in each case.

The researchers found that 7.9 per cent of males and 2.7 per cent of females were being treated for ADHD -an overall average of 5.4 per cent. 70 percent of them were prescribed ADHD-specific drugs such as Ritalin and Adderall, 19.8 per cent were receiving antidepressants and 11.9 per cent were being prescribed antipsychotics.

And while the prescription of antidepressants can be explained by the tendency for symptoms of depression and anxiety to be present alongside those for ADHD, the use of antipsychotics was less easily explained, since few of the youth, according to their records, were found to have conditions requiring treatment for psychosis.

“When we looked at the information on the children and youth with ADHD who were prescribed antipsychotics, a very, very small number of them had a condition where you would expect the use of an antipsychotic — conditions such as bipolar disorder or schizophrenia,” said senior author Dr. Paul Kurdyak, head of the mental health and addictions program at ICES, to the Canadian Press.

“We don’t know why these children and youth with ADHD are on antipsychotics, but there is a risk associated with early antipsychotic (drugs) exposure…”

This low but significant percentage of youth being prescribed antipsychotics is especially troubling, say the study’s authors, since the evidence for their efficacy in youth with ADHD is poor.

“Risperidone has a moderate impact on certain behaviours in youth with ADHD, such as oppositional and aggressive behaviour,” say the study’s authors, “but there is limited evidence to support the use of other antipsychotic medications, and they are not indicated for the core symptoms of inattention and hyperactivity.”

The known health risks associated with the use of antipsychotics in children and youth include an increased risk of type 2 diabetes, which is particularly problematic as studies have suggested that the prevalence of ADHD among youth in on the rise.

“We don’t know why these children and youth with ADHD are on antipsychotics, but there is a risk associated with early antipsychotic exposure, so we need to know more about why they are being used, so that the benefits can be weighed against the risks,” says Dr. Kurdyak.

The study’s authors say the results for prevalence of antipsychotic prescriptions for youth with ADHD in Ontario is comparable to results and patterns of medication found in other studies conducted in Canada and the United States. Demographically, the study found no statistically significant differences between the rate of youth with ADHD diagnoses in urban vs rural areas or within different economic strata.

ADHD is said to be a neurobiological disorder with genetic links which often presents as an inability to control attention, activity and behaviour often accompanied by impulsive and emotional responses. Treatment programs for ADHD commonly involve both behaviour therapy along with medications and, where available, accommodations at school.