The effect of regular caffeine consumption and caffeine withdrawal on the desire for caffeinated drinks

ISRCTN	ISRCTN13021878
DOI	https://doi.org/10.1186/ISRCTN13021878
Sponsor	University of Sussex
Funder	Biotechnology and Biological Sciences Research Council

Submission date: 15/09/2026
Registration date: 16/09/2026
Last edited: 16/09/2026

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Other

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Many people drink coffee regularly and become dependent on it, but it is unclear what motivates this behaviour. This study explored two theories that may explain coffee consumption: negative reinforcement (motivated by relief from unpleasant symptoms such as tiredness) and Incentive Sensitisation Theory (motivated by an increased urge or “wanting”).

Who can participate?
Healthy volunteers aged 18 - 50 years

What does the study involve?
Participants were screened and recruited into two groups: high (more than two cups of coffee a day) and low (less than one cup of coffee a day) coffee consumers. The study involved two laboratory-based test sessions that were conducted on separate days at least a week apart, where the participant was given either caffeine (100 mg) or placebo dissolved in and consumed as a lemon and ginger tea.

What are the possible benefits and risks of participating?
Participants were rewarded with cash or University course credits for taking part and the risks for participating were negligible.

Where is the study run from?
University of Sussex (UK)

When is the study starting and how long is it expected to run for?
February 2024 to July 2026

Who is funding the study?
Biotechnology and Biological Sciences Research Council (BBSRC) (UK)

Who is the main contact?
1. Tatum Sevenoaks, T.Sevenoaks@sussex.ac.uk
2. Martin Yeomans, martin@sussex.ac.uk

Contact information

Prof Martin Yeomans
Principal investigator

Falmer
Brighton
BN1 9RH
United Kingdom

Phone	+44 (0)1273678617
Email	martin@sussex.ac.uk

Ms Tatum Sevenoaks
Scientific, Public

Falmer
Brighton
BN1 9RH
United Kingdom

Phone	+44 (0)7384506522
Email	T.Sevenoaks@sussex.ac.uk

Study information

Primary study design	Interventional
Allocation	Randomized controlled trial
Masking	Blinded (masking used)
Control	Placebo
Assignment	Crossover
Purpose	Basic science
Scientific title	Effects of habitual caffeine consumption and caffeine deprivation on ‘wanting’ and ‘liking’ for caffeinated drinks
Study objectives	The primary objective of this study was to investigate explicit and implicit 'wanting' and 'liking' for coffee controlling for acute caffeine deprivation.
Ethics approval(s)	Approved 01/02/2024, University of Sussex Sciences and Technology Research Ethics Committee (Falmer, Brighton, BN1 9RH, United Kingdom; +44 (0)1273606755; frecsemset@sussex.ac.uk), ref: ER/TS580/9
Health condition(s) or problem(s) studied	Habitual coffee consumption
Intervention	The study implemented a randomised double-blind placebo controlled crossover design. Participants were screened and recruited into two groups: high (>2 cups of coffee a day) and low (<1 cup of coffee a day) coffee consumers. The study involved two laboratory-based test sessions that were conducted on separate days at least a week apart, where the participant was given either caffeine (100 mg) or placebo dissolved in and consumed as a lemon and ginger tea. A double-blind procedure was implemented so that neither the participants nor the researcher knew whether caffeine or placebo was administered to the participant during the testing session. The order of the caffeine and placebo conditions was randomised using a computer-generated randomisation schedule by a faculty member external to this study, who also ensured that caffeine or placebo was stored in distinct sealed containers for each study session.
Intervention type	Drug
Phase	Not Applicable
Drug / device / biological / vaccine name(s)	Caffeine
Primary outcome measure(s)	Explicit 'wanting' and 'liking' for coffee measured using explicit taste test measure at two timepoints: before and after caffeine or placebo Implicit 'wanting' and 'liking' for coffee measured using the Implicit Association Task (IAT) at one timepoint: after receiving caffeine or placebo
Key secondary outcome measure(s)	Mood measured using the Bond-Lader Mood Battery at three timepoints: before and after receiving caffeine or placebo and following the IAT before the completion of the test session
Completion date	14/07/2026

Eligibility

Participant type(s)
Age group	Adult
Lower age limit	18 Years
Upper age limit	50 Years
Sex	All
Target sample size at registration	64
Total final enrolment	64
Key inclusion criteria	Healthy volunteers
Key exclusion criteria	1. Those who smoke more than 5 cigarettes per week or vaped 2. Those taking prescription medication other than the oral contraceptive pill 3. Those who are diabetic 4. Did not drink coffee
Date of first enrolment	27/02/2024
Date of final enrolment	16/10/2025

Locations

Countries of recruitment

United Kingdom
England

Study participating centre

University of Sussex

Sussex House
Falmer
Southern Ring Road
Brighton
BN1 9RH
England

Results and Publications

Individual participant data (IPD) Intention to share	No

Editorial Notes

15/09/2026: Study's existence confirmed by the University of Sussex Sciences and Technology Research Ethics Committee.