Cognitive and Cerebral Blood Flow Effects of 2-week Caffeine Abstinence or Maintenance

Study Overview
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Brief Summary
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The purpose of this study is to determine the effects of 2 weeks caffeine abstinence as compared to 2 weeks caffeine maintenance (300mg per day)on cognition and mood. Cerebral blood flow effects will also be assessed in a subset of participants. The role of caffeine abstinence/maintenance in the acute effects of caffeine will also be explored.

Detailed Description
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The current randomised, placebo-controlled, double-blind, parallel groups study aims to explore the behavioural effects of 2-weeks caffeine abstinence as well as establishing the role of abstinence in the effects of caffeine administration by administering caffeine or placebo to those in a state of chronic and acute abstinence. This research also aims to explore, in a subset of participants, the cerebral blood flow effects of caffeine abstinence and caffeine administration using Near Infrared Spectroscopy (NIRS). Cerebral blood flow will be measured both at rest and during performance of cognitive tasks.

Official Title
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Behavioural and Cerebral Haemodynamic Effects of Caffeine Withdrawal and Caffeine Administration Following 2-week Maintenance or Abstinence

Conditions
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Cognitive Function, Mood, Cerebral Haemodynamics, Caffeine Withdrawal

Intervention / Treatment
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* Dietary Supplement: Placebo
* Dietary Supplement: Caffeine and Placebo
* Dietary Supplement: Placebo and Caffeine
* Dietary Supplement: Caffeine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male/Female 18 - 40 years Healthy Consume ≥ 150 mg caffeine daily No herbal supplements/prescription medications (excl. contraceptive pill) Non smoker Native English speaker Exclusion Criteria: Diagnosis of any significant medical condition or disorder Any known allergy or hypersensitivity to food. BMI >29.9 or <18.5 Blood pressure >139/89

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Acute withdrawal<br>Chronic intervention 100 mg caffeine capsules 3 times per day for 14 days. Acute intervention of placebo capsule on day 15. | Dietary Supplement: Caffeine and Placebo<br>* 100 mg Caffeine capsules 3 times per day for 14 days and 1 size 0 capsule of inert placebo containing silica powder CAB-O-SIL-M-5Pharma (Pharmaceutical grade)CABOT GmbH on day 15.<br>|
| Experimental: Acute caffeine-independent of withdrawal<br>Chronic intervention of placebo capsules 3 times per day for 14 days. Acute intervention of 100 mg caffeine capsule on day 15. | Dietary Supplement: Placebo and Caffeine<br>* Inert placebo capsules containing silica powder CAB-O-SIL-M-5Pharma (Pharmaceutical grade)CABOT GmbH, 1 Size 0 capsule 3 times a day for 14 days and a 100mg caffeine capsule on day 15.<br>|
| Experimental: Chronic abstinence<br>Chronic intervention of placebo capsules 3 times per day for 14 days. Acute intervention of placebo capsule on day 15. | Dietary Supplement: Placebo<br>* Inert placebo containing silica powder CAB-O-SIL-M-5Pharma (Pharmaceutical grade)CABOT GmbH. 1 Size 0 capsule 3 times a day for 14 days and 1 size 0 capsule on day 15.<br>|
| Experimental: Acute caffeine-in state of withdrawal<br>Chronic intervention of 100 mg caffeine capsule 3 times per day for 14 days. Acute intervention of 100 mg caffeine capsule on day 15. | Dietary Supplement: Caffeine<br>* Capsule containing 100 mg caffeine, one 3 times a day for 14 days and then one capsule on day 15.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cognitive performance | Performance is assessed using COMPASS (Computerised Mental Performance Assessment System), which presents a battery of standard cognitive tasks assessing aspects of attention and memory. | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mood | Mood will be evaluated using Visual Analogue Scales administered using COMPASS. | 2 weeks | 
| Cerebral haemodynamic | Cerebral blood flow will be measured in a subset of participants using Near Infrared Spectroscopy (NIRS). | 2 weeks | 
| Sleep | Quality of sleep will be measured using the Pitsburgh Sleep Quality Index (PSQI). | 2 weeks | 
| Caffeine withdrawal | Symptoms of caffeine withdrawal will be measured using a Subjective and Somatic State Questionnaire. | 2 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Caffeine, Withdrawal, Cognitive function, Mood, Cerebral haemodynamics