Effects of Stimulant Medication on Neuropsychological Functioning in Young Adults With Attention-Deficit/Hyperactivity Disorder

Abstract

consistent literature has documented significant associations between attention-deficit/hyperactivity Effects of Stimulant Medication on Neuropsychological Functioning in Young AdultsWith Attention-Deficit/Hyperactivity Disorder Objective:The main goal of this study was to evaluate the impact of stimulant medication on executive function deficits in a group of adolescents and young adults with attention-deficit/ hyperactivity disorder (ADHD; DSM-III-R criteria).Method: Male and female subjects aged 15 to 25 years were divided into 3 groups: subjects with ADHD treated with stimulants who took their medication at the time of testing (ADHD active stimulant treatment: N = 26), subjects with ADHD who had not taken stimulant medication in the past month (ADHD no stimulant treatment: N = 94), and non-ADHD control subjects (controls: N = 133). The neuropsychological battery assessed domains of cognitive functioning known to be relevant in ADHD, including tests of executive functions and learning and memory. Data were collected from July 1998 to April 2003.Results: The ADHD no stimulant treatment group had significantly lower aggregate scores compared with the controls for the total aggregate, working memory, interference control, processing speed, sustained attention, and verbal learning domains (all p < .001). The ADHD active stimulant treatment group had significantly poorer scores on the total aggregate (p = .002), interference control (p < .001), and processing speed (p = .003) domains compared with the controls. The ADHD active stimulant treatment subjects scored significantly higher on the domains of sustained attention (p = .04) and verbal learning (p = .03) compared with the ADHD no stimulant treatment subjects.Conclusions: Our study showed that subjects with ADHD who took stimulant medication had higher neuropsychological measures of attention compared with subjects with ADHD who did not take stimulant medication, but differences were not found for other measures of executive function.

Evidence of A Pharmacological Dissociation Between The Robust Effects of Methylphenidate on Adhd Symptoms and Weaker Effects on Working Memory

“…Taken together, these findings support the search for safe and effective treatments to help address WM deficits in individuals with and without ADHD. The absence of associations between CANTAB and BRIEF/BRIEF-A based definitions of WM are consistent with previous reports documenting similar absence of associations between psychometrically and behaviorally defined assessments of executive function deficits [42]. Taken together, these findings indicate that CANTAB and BRIEF/BRIEF-A definitions of WM are independent of each other.…”

A head-to-head randomized clinical trial of methylphenidate and atomoxetine treatment for executive function in adults with attention-deficit hyperactivity disorder

“…Methylphenidate not only reduces core symptoms of ADHD, but also improves many functional domains via blockage of the transporter for dopamine (DA) and norepinephrine (NE; Hechtman et al, 2004;Coghill, 2010). Moreover, some studies have demonstrated that methylphenidate can improve executive function deficits, including sustained attention (Bouffard et al, 2003;Turner et al, 2005;Wilson et al, 2006;Biederman et al, 2008b), verbal learning (Biederman et al, 2008b), verbal memory (Kurscheidt et al, 2008) and response inhibition (Aron et al, 2003;Boonstra et al, 2005) in adults with ADHD. Moreover, in a head-to-head comparison study in healthy adults, Marquand et al (2011) found that the effects of methylphenidate and atomoxetine on working memory were context-dependent.…”

Do Stimulant Medications for Attention-Deficit/Hyperactivity Disorder (ADHD) Enhance Cognition?

“…Second, Biederman et al, (2008b) showed that medication did not normalize Stroop interference control in young adults with ADHD. In our study, the Interference RT of the On Med group was normalized.…”

“…In this case, MPH did improve performance of ADHD adults on the Tower of London, but not on the verbal fluency task. Biederman et al, (2008b) administered a battery of tests to non-ADHD subjects and separate groups of ADHD patients who were either on or off medication. They found the largest beneficial effects on sustained attention (vigilance) and verbal learning, whereas stimulants did not significantly improve measures of interference (i.e.…”