Assessing therapeutic response to methylphenidate among children and adolescents with Attention-Deficit Hyperactivity Disorder: Narrative Review of its effects on emotional regulation, executive functions, and quality of life

Abstract

Attention deficit hyperactivity disorder (ADHD) is a relatively common neurodevelopmental disorder that is often accompanied, in addition to its core symptoms, by a myriad of impairments in at least some emotion regulation (ER) and executive function (EF) abilities that together translate to quality of life (QoL) impairments. Stimulants and methylphenidate in particular, have been shown to alleviate both core ADHD symptoms and some of these accompanying impairments. The objective of this review is to highlight some of the recent systematic and meta-analytic literature that discusses methylphenidate’s therapeutic effects on ADHD symptoms, ER and EF as well as its impact on the QoL of children and adolescents with ADHD. Methylphenidate’s effects have shown to be significant in terms of symptom reduction (e.g, Standard mean difference (SMD) = 0.78), ER (e.g., Cohen’s d = 0.84) and QoL (e.g., SMD = 0.61) improvement with effect sizes ranging from medium to large while its effects on EFs were relatively modest (e.g., SMD = 0.21-0.62) with effect sizes ranging from small to medium. Specifically, working memory updating showing a low effect size (e.g., SMD = 0.26), inhibitory control ranging from low to moderate with the majority showing a low effect size (e.g., SMD = 0.29), and cognitive flexibility with a moderate effect size (e.g., SMD = 0.62). In addition, Methylphenidate has shown to be less likely to be discontinued due to inefficacy, displaying good acceptability, and without significant concerns of discontinuation due to intolerability when compared to placebo. In conclusion, Methylphenidate has been shown to reduce core symptoms, improve ER, EFs, and QoL to varying degrees with conceptual and methodological issues tapering off effects as well as conclusions.