{"title":"A systematic review and meta-analysis of the acute effect of caffeine on attention.","authors":"Kasper Kløve, Anders Petersen","doi":"10.1007/s00213-025-06775-1","DOIUrl":null,"url":null,"abstract":"<p><strong>Rationale: </strong>Although there is broad agreement that caffeine provides an acute improvement in attention in the normal population, estimates of effect size vary and the relationship between dose and effect is unclear.</p><p><strong>Objective: </strong>To examine the acute effect of caffeine on attention in a systematic review and meta-analysis.</p><p><strong>Methods: </strong>PsycINFO, PubMed, and Scopus were searched for records published in English with no limits on the year of publication. Studies were included if they were randomized, double-blinded, placebo-controlled, and if they examined the acute effect of pure caffeine on behavioral tests of attention in rested, healthy adults. For every included trial, eligible outcomes were extracted and aggregated to form one composite standardized mean difference (SMD; Hedges' adjusted g) for reaction time and one for accuracy. The SMDs were then combined in random-effects meta-analyses. Additionally, several subgroup analyses were conducted, including meta-regressions on dose-response relationships.</p><p><strong>Results: </strong>Thirty-one trials with a total of 1455 participants were included in the meta-analysis. Significant effects in favor of caffeine were found for both accuracy, g = 0.27, and reaction time, g = 0.28. Subgroup analyses showed that higher doses of caffeine (≥ 200 mg) improved both reaction time and accuracy more than lower doses, but whereas a positive linear dose-response relationship was found for reaction time, a quadratic relationship was found for accuracy. The effect of caffeine was not related to differences in habitual caffeine consumption, task complexity, or which attention network was taxed.</p><p><strong>Conclusion: </strong>The current evidence shows that in the normal population, caffeine acutely enhances attention by improving both reaction time and accuracy. However, whereas higher doses continue to enhance reaction time, accuracy improves only up to a certain point before declining.</p>","PeriodicalId":20783,"journal":{"name":"Psychopharmacology","volume":" ","pages":""},"PeriodicalIF":3.5000,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Psychopharmacology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s00213-025-06775-1","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Rationale: Although there is broad agreement that caffeine provides an acute improvement in attention in the normal population, estimates of effect size vary and the relationship between dose and effect is unclear.
Objective: To examine the acute effect of caffeine on attention in a systematic review and meta-analysis.
Methods: PsycINFO, PubMed, and Scopus were searched for records published in English with no limits on the year of publication. Studies were included if they were randomized, double-blinded, placebo-controlled, and if they examined the acute effect of pure caffeine on behavioral tests of attention in rested, healthy adults. For every included trial, eligible outcomes were extracted and aggregated to form one composite standardized mean difference (SMD; Hedges' adjusted g) for reaction time and one for accuracy. The SMDs were then combined in random-effects meta-analyses. Additionally, several subgroup analyses were conducted, including meta-regressions on dose-response relationships.
Results: Thirty-one trials with a total of 1455 participants were included in the meta-analysis. Significant effects in favor of caffeine were found for both accuracy, g = 0.27, and reaction time, g = 0.28. Subgroup analyses showed that higher doses of caffeine (≥ 200 mg) improved both reaction time and accuracy more than lower doses, but whereas a positive linear dose-response relationship was found for reaction time, a quadratic relationship was found for accuracy. The effect of caffeine was not related to differences in habitual caffeine consumption, task complexity, or which attention network was taxed.
Conclusion: The current evidence shows that in the normal population, caffeine acutely enhances attention by improving both reaction time and accuracy. However, whereas higher doses continue to enhance reaction time, accuracy improves only up to a certain point before declining.
期刊介绍:
Official Journal of the European Behavioural Pharmacology Society (EBPS)
Psychopharmacology is an international journal that covers the broad topic of elucidating mechanisms by which drugs affect behavior. The scope of the journal encompasses the following fields:
Human Psychopharmacology: Experimental
This section includes manuscripts describing the effects of drugs on mood, behavior, cognition and physiology in humans. The journal encourages submissions that involve brain imaging, genetics, neuroendocrinology, and developmental topics. Usually manuscripts in this section describe studies conducted under controlled conditions, but occasionally descriptive or observational studies are also considered.
Human Psychopharmacology: Clinical and Translational
This section comprises studies addressing the broad intersection of drugs and psychiatric illness. This includes not only clinical trials and studies of drug usage and metabolism, drug surveillance, and pharmacoepidemiology, but also work utilizing the entire range of clinically relevant methodologies, including neuroimaging, pharmacogenetics, cognitive science, biomarkers, and others. Work directed toward the translation of preclinical to clinical knowledge is especially encouraged. The key feature of submissions to this section is that they involve a focus on clinical aspects.
Preclinical psychopharmacology: Behavioral and Neural
This section considers reports on the effects of compounds with defined chemical structures on any aspect of behavior, in particular when correlated with neurochemical effects, in species other than humans. Manuscripts containing neuroscientific techniques in combination with behavior are welcome. We encourage reports of studies that provide insight into the mechanisms of drug action, at the behavioral and molecular levels.
Preclinical Psychopharmacology: Translational
This section considers manuscripts that enhance the confidence in a central mechanism that could be of therapeutic value for psychiatric or neurological patients, using disease-relevant preclinical models and tests, or that report on preclinical manipulations and challenges that have the potential to be translated to the clinic. Studies aiming at the refinement of preclinical models based upon clinical findings (back-translation) will also be considered. The journal particularly encourages submissions that integrate measures of target tissue exposure, activity on the molecular target and/or modulation of the targeted biochemical pathways.
Preclinical Psychopharmacology: Molecular, Genetic and Epigenetic
This section focuses on the molecular and cellular actions of neuropharmacological agents / drugs, and the identification / validation of drug targets affecting the CNS in health and disease. We particularly encourage studies that provide insight into the mechanisms of drug action at the molecular level. Manuscripts containing evidence for genetic or epigenetic effects on neurochemistry or behavior are welcome.