An 8-year follow-up study of profiles and predictors of methylphenidate use in a nationwide sample of boys.
OBJECTIVE
To identify methylphenidate profiles over several years in a national sample of boys and examine behavioral and sociodemographic predictors of use.


METHODS
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.
Romano
Elisa
E
School of Psychology, University of Ottawa, Ottawa, Ontario, Canada. eromano@uottawa.ca
Thornhill
Stacey
S
Lacourse
Eric
E
D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D002652:Child Behavior / Q000187:drug effects*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004522:Educational Status; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D009034:Mother-Child Relations; D016017:Odds Ratio; D009864:Ontario; D010349:Patient Compliance / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D012016:Reference Values; D018570:Risk Assessment; D012959:Socioeconomic Factors; D013997:Time Factors; D016896:Treatment Outcome
D000697:Central Nervous System Stimulants; D008774:Methylphenidate