Do Children with Adhd Show Improvements in Memory and Behaviour When Stimulant Medication Dosage is Titrated?

Abstract

Abstract BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that often negatively impacts behaviour, memory, cognition, and academic achievement. Children with ADHD also exhibit deficits in executive functioning (EF). Currently, stimulant medications are the most commonly used treatment for ADHD; however, finding an ideal dose remains a challenge in the day-to-day practice of pediatricians. Medication titration is a possible option that might help in treatment. OBJECTIVES: 1) to determine if children with ADHD show improvements in both memory and behaviour when long active methylphenidate (MPH) medication dosage is titrated; 2) to report if differences exist in memory/behaviour results relative to baseline and placebo conditions. DESIGN/METHODS: A randomized controlled MPH medication trial was conducted with children ages 8-12 with a diagnosis of ADHD. Participants began with 1-week of baseline assessment, followed by a randomized 3-week trial order of placebo, low MPH dose, and high MPH dose. The Wisconsin Selective Reminding Test (WSRT) was used to measure long-term memory storage, retrieval, and learning (memory component) and the Behavior Rating Inventory of Executive Function (BRIEF) was used to measure parental perceptions of EF (behavioural component). These neuropsychological and behavioural assessment results were then graphically depicted and an optimal “best dose” determined for each child that was most effective in improving memory and behaviour. Also, a repeated-measures ANOVA was run to compare between baseline, placebo, and best dose conditions. RESULTS: A total of 19 children (10 males, 9 females) ages 8-12 (M = 10 years±1.3 years) were enrolled. Statistically significant improvements were noticed on the WSRT (F range = 22.30–48.17, p<.001), and on the BRIEF (F=22.68, p<.001) during the “best dose” condition relative to baseline and placebo. These improvements were similar across most measures for both males and females. In addition, no significant differences were noted between the baseline and placebo conditions for any measure on both the WSRT and BRIEF (F range 0 – 4.11, p range .061 – .994). CONCLUSION: When neuropsychological and behavioural test results are used to titrate medication and help with “best dose” selection, MPH appears to improve both memory and behaviour in children with ADHD. Overall, no differences were observed between baseline and placebo. Thus, a better understanding of memory and behavioural dose-response relationships may ultimately lead to targeted intervention plans that help foster long-term treatment efficacy in these ADHD children.