Precocious puberty (PP) is defined as the onset of secondary sex characteristics before age 8 in girls or age 9 in boys.
Because it accelerates skeletal maturation by prematurely shutting down the cartilage growth plate at the tip of long bones, it tends to lead to shorter height in adulthood. It is also known to place an additional psychological burden on children, especially girls. Girls are four to 38 times more likely to develop PP than boys.
Taiwan has a single-payer national health insurance system, called National Health Insurance, that encompasses 99.6% of the island’s population. The Ministry of Health and Welfare uses it to maintain the National Health Insurance Research Database (NHIRD), enabling researchers to conduct nationwide population studies.
Using this database, a Taiwanese study team investigated the relationship between ADHD and precocious puberty among children and adolescents (under 18). And because methylphenidate (MPH) is the only psychostimulant approved for the treatment of ADHD in Taiwan, the team also explored the effect of MPH on this relationship.
Most diagnoses of ADHD in the NHIRD are made by board-certified psychiatrists, enhancing diagnostic validity.
Of the more than 3.3 million persons born in Taiwan between 1997 and 2001, 186,681 were diagnosed with ADHD. Of these, 122,302 were prescribed MPH.
After adjusting for sex, low-income households, and neuropsychiatric comorbidities, children diagnosed with ADHD were twice as likely to be diagnosed with PP. This held equally true for boys and girls.
However, children diagnosed with ADHD and prescribed MPH were more than a third less likely to subsequently be diagnosed with PP than those diagnosed with ADHD but not prescribed MPH.
For girls with ADHD, who without an MPH prescription were nine times more likely than boys with ADHD to be diagnosed with PP, an MPH prescription reduced that ratio to five times more likely than boys with ADHD and prescribed MPH.
That suggests a strong protective effect of MPH.
The team concluded, “Our study found that children with ADHD were at a greater risk of PP, and girls with ADHD were a particularly vulnerable group. … MPH appeared to be protective against PP in patients with ADHD, especially in girls. However, these preliminary results need further validation.”
Yi-Chun Liu, Yin-To Liao, Vincent Chin-Hung Chen, and Yi-Lung Chen, “ADHD and Risk of Precocious Puberty: Considering the Impact of MPH,” biomedicines (2024), Vol. 12, Issue 10, 2304, https://doi.org/10.3390/biomedicines12102304.