Nearly a quarter of seniors are prescribed with anti-psychotic drugs within a year of being admitted to a Canadian nursing home, according to a study published Tuesday in the Journal of the American Geriatrics Society.

A team of researchers at various Toronto institutions studied 19,780 anonymous medical records of people admitted to nursing homes in Ontario between Apr. 1, 1998 and Mar. 31, 2000. They had not been prescribed anti-psychotic drugs previously.

Within 100 days of admission, 17% were put on anti-psychotic drugs. After a year, that number increased to 24%. Nearly 70% of those on the drugs had five or more prescriptions. And nearly 10% of residents placed on drugs were started on a dose that exceeded recommended thresholds, the study showed.

Senior author Dr. Paula Rochon said overprescribing anti-psychotics is a concern across Canada and the world.

The study was funded by the Canadian Institutes of Health Research.