Can somebody help me find the following study: Effects of Low Doses of Caffeine on Mood, Physiology and Mental Function, listed under trial identifier NCT00487227 on ClinicalTrials.gov.

It's a very interesting study regarding the effect of very low doses of caffeine on cognitive variables. The study is listed as completed but I'm unable to find the study on google, google scholar or pubmed

  • $\begingroup$ It may not have been published. Not all papers are accepted for publication. $\endgroup$
    – Arnon Weinberg
    Commented Mar 29, 2021 at 2:54

2 Answers 2


See Caffeine at levels found in decaffeinated beverages is behaviourally active Appetite Volume 50, Issues 2–3, March–May 2008, Page 559.

It's just a conference abstract though.

  • 1
    $\begingroup$ Nice!! Thanks a lot!!! $\endgroup$ Commented Mar 29, 2021 at 16:27

Short answer
Haskall et al., The effects of L-theanine, caffeine and their combination on cognition and mood, Biol Psych (2008); 77: 113–22.

Here's some of the detective work I've done:

The principal investigator of this study is listed on your link on ClinicalTrials.gov as Andrew Scholey of Northumbria University.

Looking on Google Scholar, and searching with the key terms "Andrew + Scholey + Caffeine" and looking for publications after the study's 'actual completion date', as listed on ClinicalTrials.gov, I found an article by Scholey & coworkers, namely: Haskall et al., Biol Psych (2008); 77: 113–22.

The study doesn't mention 'ClinicalTrials.gov Identifier: NCT00487227' explicitly, but given the study's senior author (Scholey), the publication date (2008) being a few years after the clinical study's completion date (2005), and the topic of the paper (cognitive effects of caffeine) that closely resembles the clinical trial's topic, I bet this is the article you're after.

Otherwise, I should simply contact Scholey - most researchers appreciate an email enquiry about their work. More often than not they're eager to spread their work across the scientific community.

  • 4
    $\begingroup$ Thanks for your effort. I doubt the the study you provided is the actual study, because the caffeine levels are very different. (2.5mg, 5mg, 10mg vs. 0mg, 150mg, 150mg & 250mg theanine, 250mg theanine) I will follow your advice and contact the author.. $\endgroup$ Commented Mar 29, 2021 at 9:00
  • 3
    $\begingroup$ @Rubus aha, I hadn't looked that specifically :) Good luck! Please add your own answer here when you find the paper. $\endgroup$
    – AliceD
    Commented Mar 29, 2021 at 9:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.