June 26, 2019
Methylphenidate — the popular central nervous system stimulant medication that comes in brand names including Ritalin, Concerta, and Daytrana, among others — remains effective in treating symptoms of attention deficit hyperactivity disorder (ADHD or ADD) in children and adolescents after two or more years of continued use, according to a study published in the American Journal of Psychiatry1.
A team of researchers from the University of Groningen in the Netherlands conducted a placebo-controlled discontinuation study using 94 children and adolescents ages 8-18 who had taken the ADHD medication methylphenidate for more than two years. A seven-week, double-blind continuation of ADHD treatment was administered to participants, or they were administered gradual withdrawal over three to four weeks with use of a placebo.
At the study’s culmination, researchers used common ADHD rating scales to compare symptoms before and after the seven-week period. They found that patients who discontinued treatment saw worsening symptoms while those who continued taking methylphenidate experienced uninterrupted symptom control, even after two years or more of treatment with methylphenidate. The ADHD Rating Scale (ADHD-RS) was the primary outcome measure, the Clinical Global Impressions improvement scale (CGI-I) and the Conners’ Teacher Rating Scale–Revised: Short Form (CTRS-R:S) were the secondary outcome measures.
Continuation and discontinuation groups had average (SD) ADHD-RS scores at baseline of 21.4 (SD=9.7) and 19.6 (SD=8.9), respectively. The average scores were 21.9 (SD=10.8) and 24.7 (SD=11.4) after 7 weeks. Between groups, the difference in change over time was −4.6 (95% CI=−8.7, −0.56), favoring the methylphenidate group. Also, The ADHD-RS inattention subscale and the CTRS-R:S ADHD index and hyperactivity subscale deteriorated substantially more in the discontinuation group. 40.4% of the discontinuation group worsened, according to the CGI-I, compared with 15.9% of the continuation group.
Researchers say the results suggest that long-term use of methylphenidate is effective, however some patients should be assessed regularly to determine whether they still have a need for methylphenidate or may function well without it.
Sources
1 Anne-Flore M. Matthijssen, et al. Continued Benefits of Methylphenidate in ADHD After 2 Years in Clinical Practice: A Randomized Placebo-Controlled Discontinuation Study. The American Journal of Psychiatry. (May 2019) https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2019.18111296