An 8-Year Follow-up Study of Profiles and Predictors of Methylphenidate Use in a Nationwide Sample of Boys

Objectives

To identify methylphenidate profiles over several years in a national sample of boys and examine behavioral and sociodemographic predictors of use.

Study design

Five cycles of a Canadian survey were used, resulting in 1447 boys followed from 2 to 3 years to 10 to 11 years. Mother reports of boys' methylphenidate use from 4 to 5 years to 10 to 11 years were used to identify profiles over time. Mother-reported sociodemographic and child behavior data at 2 to 3 years were then used to predict methylphenidate profiles.

Results

Three methylphenidate profiles were identified: no use (87.2%); slow-rising, intermittent (11.2%); and fast-rising, stable (1.6%). Sociodemographic variables were not significant predictors. Boys with greater hyperactivity-impulsivity, greater inattention, and less disruptive behavior were more likely to belong to the fast-rising, stable methylphenidate profile. Although 13% of boys were using methylphenidate over time, there were 2 heterogeneous profiles. In the first profile, there were very few initial users followed by a steady increase in the number of boys using methylphenidate over time. Among these boys, however, use was inconsistent over time. In the second profile, there was a sharp onset of methylphenidate use on school entry, followed by consistent use thereafter.

Conclusions

These findings have implications for the treatment effectiveness of attention deficit–hyperactivity disorder symptoms. It is important to continue examining the role of disruptive behavior because its co-occurrence with attention deficit–hyperactivity disorder symptoms and methylphenidate use is complex.

ADHD, Attention deficit–hyperactivity disorder, LFS, Statistics Canada's Labor Force Survey, NLSCY, National Longitudinal Survey of Children and Youth