Thyroid, Growth Hormones in Children Unaffected by 1 Year of Low-Dose ADHD Drugs
Low-dose medications to manage symptoms of attention-deficit/hyperactivity disorder (ADHD) do not appear to be associated with changes in thyroid and growth hormones over 1 year of treatment. Researchers published their findings in The Journal of Clinical Endocrinology & Metabolism.
“The trends in hormone indices of children with ADHD who received long-term medication treatment remains controversial,” explained lead author Liang-Jen Wang, MD, MPH, PhD, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taiwan, and coauthors in the study introduction.
To examine changes in growth hormone and thyroid hormone systems, the prospective study followed 118 children with ADHD over 12 months. At baseline, all participants were drug naïve. Some 22 of the children did not go on to receive any medication, while 39 were prescribed low doses of short-acting methylphenidate (14 ± 6.7 mg/d), 40 were prescribed osmotic-release oral system long-acting methylphenidate (32 ± 9.6 mg/d), and 17 were prescribed atomoxetine (29.2 ± 9.7 mg/d). Blood samples at baseline and 12 months later measured serum levels of insulin-like growth factor 1 (IGF-1), IGF binding protein 3 (IGFBP-3), prolactin, thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and free T4.
Related: Structural MRI Shows Only Modest Brain Measure Differences in Children With ADHD
According to the study, trends were similar among the 4 treatment groups for IGF-1, IGFBP-3, prolactin, TSH, T3, T4, and free T4 levels. IGF-1 changes positively correlated with changes in height and weight of all the children in the study.
Methylphenidate was linked with less gain in body weight compared with no medication, the study showed. “The ratio of MPH doses to body weight,” researchers added, “was inversely correlated with the increment in height.”
The study concluded that low doses of ADHD medications over 1 year were not linked with any thyroid or growth hormone changes.
“Nonetheless,” researchers advised, “patients’ growth and the appropriateness of drug dosage should be closely monitored.”
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