ADHD and Drug Holidays: Effects on Anthropometric Changes during Methylpenidate Treatment.

Objectives: The current study evaluated the long-term effects of methylphenidate (MPH) discontinuation on growth parameters in Turkish children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

Experimental design: 432 children and adolescents (aged 6-18 years) with ADHD receiving MPH for at least 1 year between March 2012 and January 2019 were included in a retrospective cohort study. We analyzed weight, height, and body mass index (BMI) standard deviation z scores (SDS) of groups that either did (ADHD-C) or did not (ADHD-DC) discontinue MPH. Growth parameters were converted to z scores as normative values for the Turkish population to compare the measurements at baseline and the last follow-up visit by using the paired sample t-test.

Principal observations: In patients from the ADHD-C group, statistically significant negative correlations were found between age at starting MPH and differences in weight and height SDS between baseline and follow-up. Children had a greater reduction in weight and height compared to adolescents. When we evaluated the differences in pre-and post-treatment growth factors, we found no significant differences between the groups in terms of growth parameters.

Conclusions: Our data showed that chronic use of MPH was likely responsible for changes in height and weight parameters.