Optimizing methylphenidate treatment in youths - beyond ADHD symptoms: From guideline adherence to long-term evaluations

Methylphenidate is the most frequently used medicine for the treatment of ADHD. While its short-term effects are well-known, long-term effects are much less clear.
In the first part of my thesis I investigated the effects of stopping methylphenidate (i.e., switching to a placebo) after approximately one year of use. Methylphenidate generally remained more effective than a placebo, based on teacher ratings. However, a large subgroup of children could stop using methylphenidate without deteriorating. Still, many of these children continued to use methylphenidate. Either stopping their medication or a critical reexamination of the dosage would be more fitting. Furthermore, I found that continued use of methylphenidate beyond two years has a beneficial effect on working memory.
In the second part of my thesis I investigated how well clinicians adhere to guidelines when prescribing methylphenidate. I found that guideline adherence can be improved, both during the initial dose finding phase and follow-up visits. More frequent follow-ups, better registration of height and weight, and using validated questionnaires could all contribute to reducing potential risks and overall unnecessary use of methylphenidate.
Finally, in a large database I found that better adherence to ADHD medication reduces the risk of minor offenses in adolescents, underscoring the importance of regular monitoring.
My thesis shows that optimizing methylphenidate is delicate: after one year, many children benefit from a dosage review or may stop their medication. However, methylphenidate may also reduce delinquent behavior. Thus, we need a practical, systematic evaluation method for clinical use that assesses multiple domains and helps create personalized treatment plans.