One in six adults with intellectual and developmental disabilities newly prescribed an antipsychotic
Nearly one in six adults with intellectual and developmental disabilities (IDD) in Ontario started an antipsychotic medication over six years, and more than one-quarter of them did not have a psychiatric diagnosis, according to a new study by researchers at ICES, the Centre for Addiction and Mental Health (CAMH) and the Ontario Drug Policy Research Network (ODPRN).
The study published today in BMJ Open found that of the 6,924 individuals with IDD who initiated an antipsychotic, 1,863 (26.9 per cent) had no evidence of a psychiatric diagnosis in the two years before their first prescription of an antipsychotic. The researchers also found that this group was more likely to receive their first antipsychotic prescription from a family physician than a psychiatrist (65.3 per cent vs. 47.4 per cent), and even though this group was typically on these medications for a shorter period of time, 40 per cent continued on these medications for more than a year.
“The high rate at which adults with IDD are starting antipsychotic medication is concerning as it exceeds rates that we see in other groups like the elderly, a population that has historically been the focus of attention related to overprescribing of these medications. What’s even more concerning is that this population has high rates of comorbid health issues, and may have difficulty reporting side effects, which could delay medical intervention,” says Yona Lunsky, co-author of the study, director of the Health Care Access Research and Developmental Disabilities (H-CARDD) research program at CAMH, director of CAMH’s Azrieli Adult Neurodevelopmental Centre and adjunct scientist at ICES.
Intellectual and developmental disabilities affect at least one in 100 adults and are characterized by cognitive limitations and problems with social and practical skills. Some diagnoses include Down syndrome, fetal alcohol syndrome, and autism, but many people with intellectual and developmental disabilities have non-specific diagnoses with unknown causes.
The researchers looked at the health records for more than 66,000 Ontario adults with IDD between the ages of 18 and 64 as of April 1, 2009.
“Our findings suggest that antipsychotics may be used frequently in adults with IDD for off-label indications, such as managing behavioural issues, sedation or sleep. This is concerning given the risks associated with antipsychotic use and the ongoing need to re-evaluate the risk and benefit balance of these drugs,” says Tara Gomes, a scientist at ICES and the Li Ka Shing Knowledge Institute of St. Michael’s Hospital and a principal investigator of ODPRN.
“It is time for us to give the same attention to potential overuse of antipsychotics among adults with IDD as we do for other vulnerable populations like children and the elderly,” adds Gomes.
The researchers found that being male, living in a group home and prior use of psychiatric medications were independent factors associated with being prescribed an antipsychotic. While having diabetes, high blood pressure or a previous heart attack reduced the likelihood of being prescribed an antipsychotic.
Another important finding from this study is that people with IDD and no psychiatric diagnosis, who had received multiple other medications in the year prior, were more likely to be started on an antipsychotic, while those on multiple medications with a psychiatric diagnosis, were less likely to be newly prescribed an antipsychotic.
Author block: Gomes T, Khuu W, Tadrous M, Vigod S, Cobigo V, Lunsky Y.
The study “Antipsychotic initiation among adults with intellectual and developmental disabilities in Ontario: a population-based cohort study,” is published in the July 31 issue of BMJ Open. http://dx.doi.org/10.1136/bmjopen-2018-028125.
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