Preliminary Investigation of Association between Methylphenidate and Serum Growth Markers in Children with Attention-Deficit/Hyperactivity Disorder: A Cross-Sectional Case-Control Study.

OBJECTIVES: It remains unclear whether methylphenidate (MPH) has yadverse effects on growth in children. This study aimed to investigate the association of MPH with serum biological markers of growth in children with attention-deficit/hyperactivity disorder (ADHD).

METHODS: The present study included 103 children with ADHD (64 drug-naive children, 39 MPH-treated children) and 112 control subjects. Children with ADHD were diagnosed on the basis of a semi-structured interview. Levels of biochemical markers of growth, including insulin-like growth factor-I, thyroid stimulating hormone (TSH), free T4 , calcium, phosphorus, alkaline phosphatase, vitamin D, hemoglobin, total protein, albumin, total cholesterol, and hematocrit were measured in these individuals.

RESULTS: Except in case of TSH, no intergroup differences were found in the levels of the growth markers. The levels of TSH were found to be lower in the MPH-treated boys with ADHD than in the drug-naive and control groups (p < 0.05), although the levels of TSH in all the groups were within normal limits.

CONCLUSION: In this cross-sectional study, no significant association was found between MPH and growth markers. This calls for the need to carry out prospective longitudinal research studies in the future that investigate the effect of MPH on the growth trajectory in children.