Prevalence of methylphenidate use among israeli children 1998-2004

Background: Use of methylphenidate for the treatment of attention-deficit hyperactivity disorder (ADHD) has increased throughout the world in the past decade. In Israel, as elsewhere, there is much debate regarding the diagnosis of ADHD and methylphenidate use. The aim of this study was to examine methylphenidate use rates for the treatment of ADHD among children in Israel during the years 1998-2004 with a special focus on prescriptions among girls. Study design and methods: This was a longitudinal population-based prevalence study wherein we reviewed the computerised database of a major health maintenance organisation (HMO). Subjects studied included all children living in the central district of Clalit HMO in Israel who were prescribed methylphenidate in the 7-year period from 1998-2004. Main outcome measures and results: The overall 1-year prevalence rate of methylphenidate use in children aged 0-18 years increased from 0.7% in 1998 to 2.5% in 2004, an increase by a factor of 3.54 (95% CI 3.31, 3.79). In 1998, the rate of methylphenidate prescription ranged from 0.20% among schoolgirls to 1.2% among boys, a 6-fold difference. In 2004, the rate of methylphenidate prescription ranged from 1.1% among schoolgirls to 3.8% among boys; the sex difference had narrowed to only 3.45. Except for kindergarten girls, methylphenidate utilisation increased for all ages from kindergarten to high school, both among boys and among girls. Conclusion: The continuous increasing rate of methylphenidate use in Israel, especially among girls, represents a significant public health issue. There is a need for future research into the relationship between sex and ADHD diagnosis and treatment.