Recruiting

Caffeine

Sponsor:

Hsiao-Ying Wey

Code:

NCT06763172

Conditions

Healthy

Caffeine

Adenosine

Dopamine D2/3 Receptor Availability

Eligibility Criteria

Sex: All

Age: 18 - 45

Healthy Volunteers: Accepted

Interventions

Caffeine (200 mg)

Placebo

Study Details

Brief summary:

This research study aims to determine whether and how caffeine intake affects learning process through reward feedback compared to placebo. The data acquired from this study would improve our understanding on the consequence and mechanism of caffeine intake in the aspect of learning process.

Participants will perform a reinforcement learning task (i.e. Probabilistic Selection Task) and a motor inhibition task (i.e. Go/NoGo task) in a brain scan. The scan will be done with the Siemens Biograph mMR positron emission tomography (PET)/ magnetic resonance imaging (MRI) 3 Tesla scanner. The PET allows us to see the changes in the "reward signals" - dopamine - in the brain using a radioactive dye called \[11C\]Raclopride. The MRI, on the other hand, enables us to take detailed pictures of the brain activities during cognitive tasks using a high-powered magnet. Reviewing these pictures will help us understand the influence of caffeine on reward signals and brain activities during the learning process.

Conditions

Healthy

Caffeine

Adenosine

Dopamine D2/3 Receptor Availability

Study ID

NCT06763172

Start date

May 17, 2023

Status verified date

Jan, 2025

Completion date

Dec 31, 2026

Anticipated

Primary completion date

Dec 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 45

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Age ≥ 18 and ≤ 45.
  • Habitual caffeine intake ≥ 100 mg and ≤ 450 mg daily.
  • Non-smokers.
  • Clinically healthy.
  • Have normal vision or corrected to normal vision.

Exclusion Criteria:

  • Pregnant or lactating women.
  • Women using hormonal contraceptives.
  • BMI < 18.5 or > 29.9
  • Sleep disturbance or extreme chronotype.
  • Urine test positive on one of the following substances: benzoylecgonine, morphine, d-Methamphetamine, d-Amphetamine, Benzodiazepines, Secobarbital, Methadone, Buprenorphine Glucuronide, Nortriptyline, MDMA, Oxycodone, PCP, Propoxyphene, and Cannabis/THC
  • Diagnosis of depression, anxiety, psychosis, or neurologic disorders in the last 5 years.
  • Heart or cardiovascular diseases.
  • Diabetes or other metabolic diseases.
  • Under chronic medications, for instance, painkiller and steroid.
  • Allergy to lactose (main ingredient of blank control dose)
  • Incapable to operate the tasks or comprehend the study information in English.

General MRI and PET safety exclusion criteria for all subjects:

  • Metallic foreign bodies such as cardiac pacemakers, perfusion pumps, aneurysm clips, metallic tattoos anywhere on the body, tattoos near the eye.
  • Pre-existing medical conditions including a likelihood of developing seizures or claustrophobic reactions
  • Inability to lie flat on scanner bed for about 90 min as assessed by physical examination and medical history (e.g. arthritis)
  • Recent exposure to radiation (i.e., PET from other research studies) that, when combined with this study, would be above the allowable limits
  • Pregnancy or breastfeeding: A negative serum or urine pregnancy test is required on the day of the PET procedure
  • Body weight of > 300 lbs (weight limit of the MRI scanner table)

Study Design

Enrollment

12 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Caffeine

Caffeine tablet, 200mg

placebo comparator: Placebo

Lactose tablet

Interventions

Caffeine (200 mg)

Caffeine (200mg) will be administered per os 20 minutes prior to the PET/fMRI data acquisition.

Placebo

Lactose tablet will be administered per os 20 minutes prior to the PET/fMRI data acquisition.

Primary outcome measure

  • Dopamine D2/D3 receptor availability [ Time Frame: During the PET/fMRI scan on the study day ]
  • Effects of caffeine on reinforcement learning assessed by Probabilistic Selection Task (PST) in fMRI [ Time Frame: During the PET/fMRI scan on the study day ]

Central Contacts and Locations

Central contacts

Hsiao-Ying Wey, PhD

6177241384hsiaoying.wey@mgh.harvard.edu

Locations

Athinoula A. Martinos Center for Biomedical Imaging

Recruiting

Charlestown, Massachusetts, United States, 02129

Contacts

Hsiao-Ying Wey, PhD

617-724-1384hsiaoying.wey@mgh.harvard.edu

hsiaoying.wey@mgh.harvard.edu

More Information

Sponsor

Hsiao-Ying Wey

Last update posted

Jan 9, 2025

Last verified

Jan, 2025

Keywords

  • PET/fMRI

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Hsiao-Ying Wey on 2025-01-09.