Attention-deficit/hyperactivity disorder (ADHD) involves persistent difficulty focusing, excessive motor activity, and impulsive actions. Methylphenidate is a stimulant widely used to treat ADHD in children. Serdexmethylphenidate/d-methylphenidate is a drug combination designed to provide symptom relief that starts quickly and lasts throughout the day. Researchers tested whether this combination helps Chinese children with ADHD.
The trial enrolled 55 Chinese children with ADHD across multiple centers. Participants were randomly assigned to receive either serdexmethylphenidate/d-methylphenidate capsules (28 children) or placebo, an inactive pill (27 children). Neither the children nor the people assessing outcomes knew which group received active medication. Over 3 to 4 weeks, researchers used the ADHD Rating Scale-5, a 18-question survey completed by caregivers, to measure how much symptoms improved. This scale separately tracks inattention and hyperactivity-impulsivity. Assessors also recorded clinical impressions and how children behaved in the morning and evening.
At week 3, children taking the medication improved more on total symptom scores than those on placebo. The effect size—a statistical measure of how large the difference was—was 0.61, which represents a moderate benefit. By week 4, the medication group showed larger gains on inattention, hyperactivity-impulsivity, and overall clinical ratings. Researchers reported the medication was well tolerated and identified no serious safety problems during the trial.
This result matches findings from earlier short-term studies of similar formulations in other child populations. Several important gaps remain. The study included only 55 children, a small number that makes the true benefit uncertain; a larger and more diverse group would clarify whether results apply to other ethnic backgrounds and healthcare systems. The trial ran for only 3 to 4 weeks, so whether symptom control continues beyond that point, whether children's bodies adapt to the drug over time, or what safety issues might emerge with longer use are all unknown. The supplied information does not report how often side effects occurred, how many children stopped taking the medication, or the specific methods used to keep treatment assignments secret from participants and assessors.
