Introduction
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects approximately 5% of children and 2.5% of adults [^1]. Individuals with ADHD often experience impairments in psychosocial, physical, and societal functioning, leading to a decrease in overall quality of life [^1]. While medication, such as stimulants and non-stimulants, is a crucial part of managing ADHD and can greatly improve outcomes, there is a persistent gap between evidence-based guidelines and their implementation in clinical practice [^1] [^2]. This gap creates uncertainty about the effective use of ADHD medication.
The Benefits of ADHD Medication
ADHD medication has been shown to have significant short-term benefits in reducing core symptoms of ADHD [^1] [^6]. Numerous randomized controlled trials have demonstrated the efficacy of medication in managing ADHD symptoms [^1] [^6]. Additionally, observational studies have highlighted the positive effects of pharmacological treatment on important behavioral and functional outcomes, such as reducing the risk of injuries, accidents, substance use disorders, criminal convictions, and improving educational outcomes [^7] [^8].
Longitudinal studies have indicated that two-thirds of individuals with ADHD continue to experience impairing symptoms into adulthood, emphasizing the need for long-term treatment and support [^5]. Research has shown that medication use for up to 2 years is generally safe, and even after 2 years of treatment, methylphenidate has been found to effectively manage ADHD symptoms [^9] [^10].
Challenges of ADHD Medication Adherence
Despite the proven benefits of ADHD medication, there is a significant challenge in achieving consistent adherence to treatment. Previous studies have reported high rates of medication discontinuation, with 50-80% of individuals discontinuing medication within 1-2 years of initiation [^11] [^12] [^13] [^14] [^15] [^16]. These discontinuation rates exceed the expected age-related decreases in symptoms, suggesting premature discontinuation of medication in individuals whose symptoms persist [^5] [^17].
Various factors contribute to medication non-adherence and discontinuation. These include medication side effects, poor response, dosing inconvenience, stigma, and patient attitudes [^16]. Furthermore, the variation in methods and measures used to assess medication discontinuation makes it challenging to compare results across studies and countries [^13] [^16]. It is, therefore, crucial to address these barriers and improve medication adherence to optimize treatment outcomes in individuals with ADHD.
The Importance of Long-Term ADHD Medication Persistence
Understanding long-term medication persistence is essential for effective ADHD management. A multinational study examining ADHD medication persistence found that 30-60% of patients remained on medication for up to 5 years, considering reinitiation of treatment [^21]. This suggests that many individuals with ADHD reinitiate treatment after medication breaks, indicating the importance of considering medication persistence beyond initial discontinuation rates.
However, medication discontinuation and persistence rates vary significantly by age. Adolescents and adults have higher rates of early discontinuation compared to children [^21]. Late adolescence and early adulthood emerge as crucial intervention windows to reduce premature treatment cessation. The cause of treatment discontinuation is multifactorial, and factors contributing to discontinuation likely differ across the lifespan. Further investigation is needed to understand these factors and develop strategies to improve treatment adherence across age groups.
ADHD Medication Adherence Across Countries and Sexes
A multinational study examining ADHD medication discontinuation and persistence across nine countries and regions found similarities in treatment patterns. Early discontinuation rates were higher in adolescents and adults compared to children [^21]. This highlights the need for targeted interventions and support during the transition from childhood to adolescence and from adolescence to adulthood to ensure continued adherence to medication.
Furthermore, the study found that while a higher number of males with ADHD received medication compared to females, this difference decreased with age [^21]. The patterns of discontinuation and persistence were similar across sexes, emphasizing the importance of addressing medication adherence in both males and females with ADHD.
Strategies to Improve ADHD Medication Adherence
Improving medication adherence in individuals with ADHD requires a multifaceted approach. Healthcare providers should prioritize patient education and address concerns related to medication side effects, dosing inconvenience, and stigma. Open communication and shared decision-making between patients, caregivers, and healthcare providers can help set realistic expectations about treatment outcomes, promoting a sense of ownership and increasing commitment to medication adherence.
In addition to addressing patient concerns, healthcare systems should strive to simplify medication regimens and provide support services to promote adherence. This can include reminders, monitoring tools, and follow-up appointments to assess treatment response and adjust medication as needed. Collaborative care models involving healthcare providers, educators, and families can help create a supportive environment for individuals with ADHD, improving treatment adherence and overall outcomes.
Conclusion
Optimizing medication adherence is crucial for maximizing the benefits of ADHD treatment. While ADHD medication has proven efficacy in managing symptoms and improving functional outcomes, high rates of medication discontinuation pose a significant challenge to treatment success. Understanding the factors contributing to non-adherence and developing strategies to improve medication persistence across age groups and sexes is essential.
By addressing patient concerns, providing education, and implementing support services, healthcare providers can enhance medication adherence in individuals with ADHD. Collaborative care models and shared decision-making further promote patient engagement and treatment commitment. By optimizing medication adherence, we can improve the long-term outcomes and quality of life for individuals with ADHD.