Clinical trial NCT02461693: Evaluating the Role of Expectations in Response to Caffeine Consumption: An RCT
Official title: Evaluating the Role of Expectations in Response to Caffeine Consumption: A Randomized Control Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Caffeine
Affect
Cognitive Ability, General
Mood
Keywords: Vigilance
Mood
Randomized Controlled Trial
Probability
Lead sponsor: University of Alabama at Birmingham
Sponsor class: OTHER
First posted: 2015-06-03
Enrollment: 205
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief summary: The purpose of this project is to examine the effect of expectancy on mood and alertness after consumption of caffeine "treatment" or placebo "control" pill, given that participants know their probability for receiving the caffeine versus placebo pill. Participants will be randomly assigned a probability (ranging from 0-100%) of receiving caffeine vs. placebo, and this probability will be revealed to them before consumption of the assigned pill and subsequent cognitive testing. At the time of consumption, neither study staff administering the intervention nor participants will know for certain which pill is given to each participant. Pill assignment will depend on pre-determined randomization probabilities, which will be provided and assigned by the study statistician. By revealing participants' individual probability of receiving the caffeine pill, we will induce positive or negative expectancies regarding likelihood for receipt of the caffeine pill. These experimental manipulations will: 1) estimate the effect of expectancy on cognitive and affective outcomes, and 2) allow for a more direct estimate of the effect of the caffeine pill under real-world conditions than would a conventional randomized trial.


Eligibility criteria: Inclusion Criteria:

* 18 years-old or older
* available to participate on the dates specified
* willing to take a caffeine or placebo pills at study session
* willingness to abstain from caffeine for 12 hours prior to study visit (8:30pm-8:30am)
* UAB employees or students with some college education (including current enrollment)

Exclusion Criteria:

* self-reported use of ADHD medication
* self-reported use of anxiety medication
* self-reported use of sleep medication
* self-reported use of nicotine products
* self-reported lactose intolerance
* self-reported uncorrected vision
* self-reported pregnancy or trying to become pregnant

Primary outcomes:
measure: Mood State Score on POMS-2 Test
timeFrame: 30 minutes post pill consumption
measure: Vigilance Score on Computer-based Test Using Random, Visual Stimulus: Proportion Correct (Out of 60)
timeFrame: 45 to 105 minutes post pill consumption
measure: Vigilance Score on Computer-based Test Using Random, Visual Stimulus: Number Correct, Number of False Alarm Hits
timeFrame: 45 to 105 minutes post pill consumption
measure: Vigilance Score on Computer-based Test Using Random, Visual Stimulus: Mean Time to a Correct Hit
timeFrame: 45 to 105 minutes post pill consumption
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: University of Alabama at Birmingham
name: David B Allison, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: George BJ, Li P, Lieberman HR, Pavela G, Brown AW, Fontaine KR, Jeansonne MM, Dutton GR, Idigo AJ, Parman MA, Rubin DB, Allison DB. Randomization to randomization probability: Estimating treatment effects under actual conditions of use. Psychol Methods. 2018 Jun;23(2):337-350. doi: 10.1037/met0000138. Epub 2017 Apr 13.