The effect of prior caffeine consumption on neuropsychological test performance: a placebo-controlled study

Abstract

Background: The aim of this study was to investigate whether the prior consumption of 200mg of pure caffeine affected neuropsychological test scores in a group of elderly participants aged over 60 years. Method: Using a double blind placebo vs. caffeine design, participants were randomly assigned to receive 200mg of caffeine or placebo. A neuropsychological assessment testing the domains of general cognitive function, processing speed, semantic memory, episodic memory, executive function, working memory and short-term memory was carried out. Results: Significant interaction effects between age, caffeine and scores of executive function and processing speed were found; participants who had received caffeine showed a decline in performance with increasing age. This effect was not seen for participants who received placebo. Conclusion: The results highlight the need to consider and control prior caffeine consumption when scoring neuropsychological assessments in the elderly which is important for accuracy of diagnosis and corresponding normative data.