The effects of psychostimulants on cognitive functions in individuals with attention-deficit hyperactivity disorder: A systematic review

Andrea Mckenzie; Shakila Meshkat; Leanna M W Lui; Roger Ho; Joshua D Di Vincenzo; Felicia Ceban; Bing Cao; Roger S McIntyre

doi:10.1016/j.jpsychires.2022.03.018

The effects of psychostimulants on cognitive functions in individuals with attention-deficit hyperactivity disorder: A systematic review

J Psychiatr Res. 2022 May:149:252-259. doi: 10.1016/j.jpsychires.2022.03.018. Epub 2022 Mar 11.

Authors

Andrea Mckenzie¹, Shakila Meshkat², Leanna M W Lui², Roger Ho³, Joshua D Di Vincenzo⁴, Felicia Ceban², Bing Cao⁵, Roger S McIntyre⁶

Affiliations

¹ Mood Disorder Psychopharmacology Unit, University Health Network, Toronto, ON, Canada. Electronic address: andrea.mckenzie@uhn.ca.
² Mood Disorder Psychopharmacology Unit, University Health Network, Toronto, ON, Canada.
³ Department of Psychological Medicine, National University Health System, Singapore; Institute for Health Innovation and Technology (iHealthtech, National University of Singapore, Singapore.
⁴ Mood Disorder Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.
⁵ Key Laboratory of Cognition and Personality, Faculty of Psychology, Ministry of Education, Southwest University, Chongqing, 400715, PR China.
⁶ Mood Disorder Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada. Electronic address: roger.mcintyre@uhn.ca.

PMID: 35303614
DOI: 10.1016/j.jpsychires.2022.03.018

Abstract

Background: Attention-deficit/hyperactivity disorder (ADHD) is associated with a broad range of deficits in cognitive functions which has significant implications for quality of life. Psychostimulants are demonstrated to improve symptoms of inattention and hyperactivity/impulsivity, however, their impact on cognition remains incompletely characterized. Herein, the aim of this systematic review is to synthesize the extant literature reporting on the effects of psychostimulants on cognitive function in individuals with ADHD.

Method: A systematic search of PubMed, Scopus, and Web of Science from inception to July 2021 was conducted. Additional studies were identified through Google Scholar and a manual search of the reference lists of relevant articles. Inclusion criteria were original studies that evaluated the cognitive function of individuals with ADHD taking psychostimulants drugs. We assessed the quality of the included papers using the Newcastle-Ottawa scale (NOS).

Results: A total of 10 studies involving 753 subjects with ADHD and 194 healthy controls were identified and eligible for inclusion. Nine studies evaluated the impact of methylphenidate on cognitive function and one study investigated the use of lisdexamfetamine. Results indicated that attentional deficits such as memory, vigilance, divided attention, phasic and tonic alertness, and focused attention were improved in ADHD patients treated with psychostimulants. The efficacy of psychostimulants in improving other domains of cognition remains inconclusive due to conflicting evidence or insignificant findings (ie. academic performance and executive function). Overall, results indicate that psychostimulants may improve only select domains of cognition (ie. memory and attention).

Conclusion: Psychostimulants are reported to improve several disparate aspects of cognition among individuals with ADHD. Further research is needed to better understand the complex relationships between cognition and behavior in ADHD, as well as the impact of medication on these distinct aspects of functioning. Further research is also needed to determine whether the pro-cognitive effect of stimulants would be transferable to other mental disorders.

Keywords: ADHD; Attention deficit hyperactivity disorder; Cognition; Depression; Executive function; Memory; Psychostimulants.

Publication types

Review
Systematic Review

MeSH terms

Attention Deficit Disorder with Hyperactivity* / complications
Central Nervous System Stimulants* / pharmacology
Central Nervous System Stimulants* / therapeutic use
Cognition
Humans
Methylphenidate* / pharmacology
Methylphenidate* / therapeutic use
Quality of Life

Substances

Central Nervous System Stimulants
Methylphenidate