A Study about Long-Term Effects of Attention-Deficit Hyperactivity Disorder Medication on Height and Weight in the Korean School-Aged Boys with Attention-Deficit Hyperactivity Disorder Based on Observation of Natural Course

Objectives:This study was conducted naturalistically in order to observe the long-term effects of attention-deficit hyperactiv- ity disorder (ADHD) medications on growth rates among Korean school-aged boys with ADHD. Methods:Participants in the study were boys with ADHD aged 6 to 11 years who have taken ADHD medication, methylphe- nidate (extended release) or atomoxetine. They attended scheduled visits monthly or bimonthly for clinical assessment with mea- surement of height and weight. In this study, 35 boys with ADHD (mean age at baseline=7.90±1.77 years ; mean age at endpoint= 12.54±1.91 years) were included, with a mean follow-up period of 4.64 years (±1.62 years), ranging from 2 to 9.7 years. Height, weight, and body mass index (BMI) measurements were converted to "age-corrected Z-scores" using data from Growth Charts provided by the Korean Center for Disease Control and Prevention from 2007. Results:Age-corrected endpoint growth parameters (height, weight, BMI Z-scores) did not differ significantly from the baseline values (height t=0.027 ; weight t=-0.61 ; BMI t=-1.86, in paired t-test). Especially high correlation was observed between the baseline and endpoint height Z-scores (r=0.876, p<.001), for which the coefficient of determination r 2 was 0.767, meaning that the amount of variability in endpoint height Z-scores explained by the baseline height Z-scores was 76.7%. Conclusion:Our results suggested that the long-term effects of ADHD medications on growth parameters to be tolerable in Korean school-aged boys with ADHD.