Summary: Long-term treatment with both stimulant (Methylphenidate) and non-stimulant (Atomoxetine) medications significantly improves cognitive functions in individuals with ADHD. The study highlights improvements in attention, inhibition, reaction time, and working memory, which are crucial for academic and occupational performance.
This research underscores the importance of considering cognitive function alongside behavioral treatment for ADHD. The findings offer new insights into the efficacy of chronic medication use in managing ADHD symptoms over the long term.
Key Facts:
- Both stimulant and non-stimulant medications improve cognitive functions in ADHD patients.
- The study found significant enhancements in attention, inhibition, reaction time, and working memory.
- Long-term medication use is shown to be as effective as short-term use in improving cognition.
Source: King’s College London
Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most prevalent neurodevelopmental disorders and can persist into adulthood in the majority of cases.
ADHD is associated with deficits in cognitive functions, in particular executive functions such as motor and interference inhibition, sustained attention, working memory, timing, psychomotor speed, reaction time variability and switching.
This is the first meta-analysis paper of chronic medication effects on cognition in ADHD, looking at attention, inhibition, reaction time and working memory. All of these aspects can affect academic performance in school, and occupational performance in adults.
“The findings of this meta-analysis offer opportunities to further explore the use of stimulant and non-stimulants in the treatment of ADHD. Finding that cognitive function was comparatively improved in long term stimulant and non-stimulant treatment has implications for school and work performance for children and adults.
“This is an important aspect of ADHD treatment, alongside behaviour, as children particularly tend to exhibit problems with working memory and attention which can result in poor academic performance.
“Focus can be on behavioural improvements, but cognitive function is an important part of understanding and treating ADHD,” said Professor Katya Rubia, Department of Child & Adolescent Psychiatry, King’s IoPPN.
The meta-analysis shows for the first time that chronic Methylphenidate and Atomoxetine have comparable effects of improving executive functions in people with ADHD when taken over a longer period of time. For both drugs the best effect was on improving attention.
Previous meta-analysis has looked at single dose effects, but this is not quite as clinically significant as looking over a longer period, which reflects more typical administration of the drugs.
Previously, stimulants were considered to be the more effective treatment for cognition improvement, but this shows that non-stimulant treatment is comparable over longer term.
About this ADHD, cognition, and psychopharmacology research news
Author: Katya Rubia
Source: King’s College London
Contact: Katya Rubia – King’s College London
Image: The image is credited to Neuroscience News
Original Research: Open access.
“The effects of chronic administration of stimulant and non-stimulant medications on executive functions in ADHD: A systematic review and meta-analysis” by Katya Rubia et al. Neuroscience and Biobehavioral Reviews
Abstract
The effects of chronic administration of stimulant and non-stimulant medications on executive functions in ADHD: A systematic review and meta-analysis
Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with executive function deficits that are improved with medications. However, meta-analyses of stimulant effects on cognition have mostly tested single-dose effects, and there is no meta-analysis of non-stimulant effects.
This systematic review and meta-analysis tested the clinically more relevant longer-term effects of Methylphenidate (20 studies; minimum 1 week) and Atomoxetine (8 studies; minimum 3 weeks) on reaction time, attention, inhibition, and working memory, searching papers on PubMed, Embase, Ovid MEDLINE, and PsycINFO.
The meta-analysis of 18 studies in 1667 subjects showed that methylphenidate was superior to placebo in all cognitive domains with small to medium effect sizes (Hedges g of 0.34–0.59).
The meta-analysis of atomoxetine included 7 studies in 829 subjects and showed no effects in working memory, but superior effects in the other domains with medium to large effect sizes (Hedge’s g of 0.36–0.64). Meta-regression analysis showed no drug differences on cognitive effects.
The meta-analyses show for the first time that chronic Methylphenidate and Atomoxetine have comparable effects of improving executive functions in people with ADHD.
