Methylphenidate Remains Effective for ADHD After Two Years of Regular Use

There is a wealth of evidence that methylphenidate can improve attention-deficit/hyperactivity disorder (ADHD) symptoms in the short term, but there are limited data on the long-term benefits of this medication. According to a study in AJP in Advance, youth with ADHD who have taken methylphenidate for two or more years continue to benefit from methylphenidate when compared with peers who are temporarily taken off this medication.

Anne-Flore Matthijssen, M.Sc., of Groningen University in the Netherlands and colleagues enrolled 94 children and adolescents aged 8 to 18 who had been taking methylphenidate regularly for at least two years. The participants were randomly assigned to either continue their treatment or go on gradual discontinuation (three weeks of drug tapering followed by four weeks of placebo medication).

At the end of seven weeks, ADHD symptom scores (assessed with the investigator-rated ADHD Rating Scale) remained stable among children taking methylphenidate (from 21.4 to 21.9) but increased among those who discontinued the medication (from 19.6 to 24.7). Similar outcomes were seen when using a teacher-rated symptom assessment (Conners’ Teacher Rating Scale–Revised: Short Form).

The authors found that the benefits of continuing to take methylphenidate were superior among participants 13.8 years and younger; youth older than 13.8 years did not have significantly worse symptoms on average upon discontinuing their medication.

Matthijssen and colleagues cautioned that most eligible families they contacted declined to enroll their children. “[O]ur sample likely included an overrepresentation of families who suspected that the medication may not have been working well and therefore wanted to try going off medication,” the authors wrote. “Those who declined to participate may have felt more confident that the medication was helpful and may therefore have been unwilling to risk being assigned to the placebo condition.” This recruitment issue may partially explain why the differences between the methylphenidate and discontinuation groups was modest.

“Nevertheless, the fact that most participants in our study did not experience significant worsening after discontinuation of methylphenidate supports guideline recommendations to periodically assess whether there is a continued need for methylphenidate treatment, for example, by considering a temporary discontinuation of medication in clinical practice to prevent unnecessary long-term medication use,” the authors concluded.

For related information, see the Psychiatric News article “Noninvasive Electrical Stimulation Shown Effective for ADHD.”

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