View clinical trials related to Caffeine.
Filter by:Caffeine is the most used psychoactive drug in Canada, with regular consumption by 88% of the adult population, While rates of caffeine consumption are considered to be high in the general population, there is some evidence that they may be even higher within schizophrenia patients; in a 2006 U.S. study, daily consumption rates of caffeine were nearly double those observed in a healthy control population (471.6 mg/day vs. 254.2 mg/day). Furthermore, 13% of the schizophrenia population studied ingested more than 1000 mg/day of caffeine, well above the 400 mg daily maximum recommended by Health Canada. High doses of caffeine are particularly concerning for individuals with schizophrenia; caffeine alters dopaminergic activity at post-synaptic neurons through its actions at adenosine A2A receptors, which may exacerbate positive symptoms, such as delusions and hallucination. This significant rate of consumption is likely due in part to caffeine's actions on the human brain, resulting in increased arousal, elevated mood and beneficial effects on a wide-range of cognitive processes including verbal working memory, sustained attention, and executive function. These areas of caffeine-induced cognitive improvement notably overlap with the cognitive domains that are reported to be diminished in schizophrenia. Despite this overlap and the rates of caffeine consumption observed within schizophrenia, research reports examining the effects of caffeine on cognition and brain activity are all but non-existent in this population. The primary objective of this proposal is to compare the effects of caffeine and placebo on brain function during cognitive tasks in participants with schizophrenia. While the investigators have specific hypotheses for each task, overall the investigators hypothesize that caffeine will improve cognitive function (as evidenced by larger ERP amplitudes and/or reduced ERP latencies) compared to placebo in schizophrenia patients, with similar effects (albeit reduced in magnitude) observed in non-patient healthy controls.
Objective: Assess the effect of caffeine in the following vestibular function tests: Cervical Vestibular Evoked Potential (cVEMP), Ocular Vestibular Evoked Potential(oVEMP) and Caloric Test. Methods: Randomized, prospective triple-blind, placebo controlled clinical trial. All participants underwent otoscopy, tympanometry, responded to the Profile of Mood State (POMS), submitted to the cVEMP, oVEMP and caloric tests. After that they received placebo or caffeine capsule (300mg) and repeated the procedures 45 minutes after.
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.
Almost all infants born <29 weeks gestational age develop apnea of prematurity and are treated with caffeine. Type of diet and disease states may be significant contributors of variability in caffeine metabolism and pharmacokinetics (PK) in this population. This prospective, observational, open-label, opportunistic PK study will compare the population PK of caffeine between infants fed formula and infants fed exclusively breast milk; compare the activities of caffeine metabolizing enzymes between infants fed formula and infants fed exclusively breast milk; and determine the effect of hypoxia, hypotension, and infection on caffeine PK and metabolism in premature infants.
The purpose of this study is to observe effects of caffeine on overactive bladder symptoms and wellbeing. This study looks at whether caffeine has bad effects on urinary symptoms or if lower doses of caffeine decrease the effects. The study will propose the following hypothesis: 1. The voiding and mental health symptoms will be greatest in the high dose treatment and lowest in the placebo treatment. 2. The low dose treatment will produce more voiding and mental health symptoms than the placebo treatment. 3. Voiding and mental health symptoms will be mediated by hydration status of the patient which will be assessed using a Tanita Scale.
The aim is to investigate the influence of caffeine on heart rate variability and on performance in a 3 min exercise test in different population groups (able-bodied, paraplegic and tetraplegic subjects). In general, the investigators are interested in the differences between the heart rate variability before and after caffeine supplementation and if the subjects exercise performance is enhanced using this type of supplementation. Another objective is to see whether there are differences between able-bodied and disabled subjects. Tetraplegic subjects showed in some previous studies no Low-Frequency-component (LF) for heart rate variability and no increase in catecholamines after the ingestion of caffeine. Therefore the investigators think, that tetraplegic subjects won`t show any ergogenic effect in exercise performance after the intake of caffeine. On the other hand, paraplegic subjects should show similar differences of heart rate variability after the ingestion of caffeine as able-bodied subjects. Paraplegic subjects should benefit from caffeine supplementation in an increase in exercise performance.
The Hershey Company is interested in investigating the effects of various chocolate beverages on brain physiology and cognitive function. The main substances in the drinks that are known to influence the brain are caffeine and related chemicals such as theobromine. Caffeine and chemicals related to caffeine are all naturally occurring and all potentially alter brain physiology. This study will evaluate changes in brain blood flow and cognition following the consumption of drinks with various combinations of the Primary Ingredients. The study proposed here will evaluate ingredients in a 4-arm cross-over double-blind design in an attempt to understand the differential effects of these compounds in chocolate drinks.
The Hershey Company is interested in investigating the effects of various chocolate beverages on brain physiology and cognitive function. The main substances in the drinks that are known to influence the brain are caffeine (and related chemicals such as theobromine) and flavonoids. Flavonoids are chemical found in plants and are most commonly associated with antioxidant activity. Caffeine, chemicals related to caffeine, and flavonoids are all naturally occurring and all potentially alter brain physiology. This study will evaluate changes in brain blood flow and cognition following the consumption of drinks with various combinations of the Primary Ingredients. Caffeine is likely to have peak effects within 1-hour of ingesting the chocolate while the flavonoids are likely to have peak effects 3-4 hours after ingestion. The study proposed here will evaluate ingredients in a 4-arm cross-over double-blind design in an attempt to understand the differential effects of these compounds in chocolate drinks.
Premature infants are at risk of having pauses in breathing, or apneas, due to their immaturity. Premature infants are routinely given caffeine, a respiratory stimulant, on the first day of life to prevent apneas. However, if they continue to have apneas, they may require a breathing tube to be placed in the trachea. There are risks to having a breathing tube, so it would be beneficial to avoid it if possible. If caffeine is given earlier, it may decrease the need for a breathing tube. Some studies also suggest that caffeine may also improve heart function which may prevent low blood pressure if given early.
The main purposes of this randomized cross-over trial are to characterize and compare the effects of a moderate dose of caffeine intake in healthy physically active males on hydration and energy metabolism specifically: 1. Total body water and its compartments (intracellular and extracellular) assessed by by dilution techniques, and hydration state by urine specific gravity; 2. Total energy expenditure by double labeled water, resting energy expenditure by indirect calorimetry, and physical activity energy expenditure; 3. Energy expenditure in physical activity of daily living, in particular duration and intensity of activity. 4. If the changes occurred between placebo and caffeine ingestion on the main outcomes were dependent on specific covariates, namely body composition and dietary intake.