Prevalence of methylphenidate use among adolescents in Ontario.

Despite a growing interest in the use of methylphenidate (Ritalin) to treat attention deficit/hyperactivity disorders, prevalence data has been scarce in Canada. A probability school survey conducted in 1997 among Ontario students in grades 7, 9, 11 and 13 is used to collect data on such use. Overall, 3.4% of students (5.3% of males, 1.7% of females) used methylphenidate in the previous year. Rates and patterns are similar to those found in the United States. Future research needs to examine reasons and correlates of use, extent of medical supervision and possible non-medical use of methylphenidate.