Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder commonly diagnosed in youth. One of the primary treatment approaches for managing ADHD symptoms is medication. However, concerns have been raised about the potential impact of these medications on growth trajectories in children. In a recent study conducted by Karl Weddige, PhD, and his colleagues, the growth trajectories of youth on different ADHD medications were compared. The study revealed interesting findings regarding the weight and height trajectories of youth on lisdexamfetamine dimesylate (LDX; Vyvanse) and delayed release/extended-release methylphenidate (DR/ER-MPH; Jornay PM). This article critically examines the study’s methodology, results, and implications, shedding light on the effects of ADHD medications on growth in youth.
The study conducted by Weddige et al. included a sample of youth diagnosed with ADHD who were newly prescribed one of three medications: LDX, DR/ER-MPH, or osmotic release oral system methylphenidate (OROS MPH; Concerta). The researchers analyzed weight and height trajectories of the youth over a one-year period after starting the medication. The results indicated that youth on DR/ER-MPH exhibited a greater weight trajectory compared to those on LDX. The difference in weight trajectory was statistically significant (P<0.0001), suggesting that DR/ER-MPH may lead to greater weight gain in the first year of treatment. However, it is important to note that the sample size of patients on DR/ER-MPH was small, potentially impacting the accuracy and generalizability of the findings.
In addition to comparing LDX and DR/ER-MPH, the researchers also examined the growth trajectories of youth on DR/ER-MPH and OROS MPH. Although the differences in weight and height trajectories between these two medications were not statistically significant, there were numerical variations favoring DR/ER-MPH. These findings suggest the possibility of differential effects on growth between different ADHD medications. However, as the researchers acknowledge, the small sample size of patients on DR/ER-MPH limits the reliability of these results.
Weddige explained that DR/ER-MPH is an evening-dosed, delayed-release, and extended-release methylphenidate that is absorbed in the colon. Its pharmacokinetic profile is characterized by a monophasic curve and an extended elimination phase. This smooth profile, with fewer peaks and troughs in methylphenidate plasma concentration, is hypothesized to be associated with less appetite suppression throughout the day. This may explain the greater weight trajectory observed in youth on DR/ER-MPH compared to LDX.
While the study provides valuable insights into the growth trajectories of youth on different ADHD medications, several limitations must be acknowledged. The small sample size of patients on DR/ER-MPH reduces the generalizability of the findings related to this specific medication. Additionally, the study’s retrospective design and reliance on electronic health record databases may introduce bias and limit the accuracy of the growth trajectory models. Furthermore, the study period coincided with the onset of the COVID-19 pandemic, which may have influenced growth patterns in youth, confounding the results.
Future research should aim to address these limitations and expand the understanding of how different ADHD medications impact growth trajectories in youth. Large-scale prospective studies with more diverse samples and longer follow-up periods would provide more robust evidence. Furthermore, investigating other factors such as age, gender, and comorbidities in relation to growth trajectories would enhance our understanding of the complex interactions between ADHD medications and growth.
The study conducted by Weddige and colleagues sheds light on the growth trajectories of youth with ADHD on different medications. The findings suggest that DR/ER-MPH may lead to a greater weight gain trajectory in the first year of treatment compared to LDX. However, the small sample size and limitations of the study warrant caution in interpreting these results. Further research is needed to validate and expand upon these findings, considering the potential impact of confounding factors and the generalizability of the results to a broader population of youth with ADHD. Ultimately, healthcare professionals should consider both the benefits and potential effects on growth when prescribing ADHD medications to youth, ensuring individualized and comprehensive treatment approaches.