Study Title and Description
Caffeine withdrawal, acute effects, tolerance, and absence of net beneficial effects of chronic administration: cerebral blood flow velocity, quantitative EEG, and subjective effects.
Key Questions Addressed
|1||For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on behavior*?|
Primary Publication Information
|Title||Caffeine withdrawal, acute effects, tolerance, and absence of net beneficial effects of chronic administration: cerebral blood flow velocity, quantitative EEG, and subjective effects.|
|Author||SC Sigmon,RI Herning,W Better,JL Cadet,RR Griffiths,|
Secondary Publication Information
There are currently no secondary publications defined for this study.
Extraction Form: Behavior - Design Details - INCLUDED Studies
No arms have been defined in this extraction form.
|Question... Follow Up||Answer||Follow-up Answer|
|What outcome is being evaluated in this paper?||Behavior|
|What is the objective of the study (as reported by the authors)?||Caffeine withdrawal, acute caffeine effects, caffeine tolerance, and net beneficial effects of chronic caffeine administration were investigated using cerebral blood flow velocity,quantitative EEG and subjective effects.|
|Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods)||The 7-week outpatient study used a double-blind, within-subject cross-over design to examine the effects of acute caffeine and placebo administration under conditions of caffeine maintenance (400 mg per day) and placebo maintenance (cf. Table 1). Within each maintenance phase, subjects participated in two challenge sessions (a caffeine and a placebo challenge session). Order of challenge sessions was mixed within and across subjects.Participants were maintained on placebo or caffeine for a minimum of 14 days before the first challenge session. Each challenge session consisted of oral administration of either caffeine(200 mg b.i.d.) or placebo (b.i.d.), followed by collection of subjective and physiological measures (described below). At one visit per week, participants received a new container of capsules for the upcoming week and returned the empty container. During the caffeine maintenance phase, they ingested a capsule containing 200 mg caffeine anhydrous twice daily, once between 8 and 9 AM in the morning and then again between 2 and 3 PM, fora total daily caffeine dose of 400 mg. During the placebo maintenance phase, participants ingested a placebo capsule twice daily (8-9 AM and 2-3 PM). For the eight subjects who received the caffeine maintenance phase first, caffeine content in the daily capsules was gradually reduced during the first 3 days of the subsequent placebo maintenance phase to minimize caffeine withdrawal symptoms when switching from the caffeine to placebo maintenance condition. The subjective effects measured included the Profile of Mood States (POMS), a 65-item questionnaire designed to assess mood states (McNair et al. 1971) and a 33-item subjective questionnaire, a portion of which was previously reported to be sensitive in measuring caffeine withdrawal (e.g., Griffiths et al. 1990; Jones et al. 2000). Although questionnaires were completed at every study visit, only those from the 4 challenge sessions were used in data analyses. On challenge days, subjects completed the questionnaires approximately 20 minutes after the afternoon capsule and were instructed to respond based on how they felt at the time of assessment. A single factor (drug condition) ANOVA was performed on the raw scores of each of the subjective measures using the planned post-hoc comparisons described above. All statistical significance was indicated at P=0.05. Adjustments for sphericity were done using Huynh-Feldt corrections.|
|How many outcome-specific endpoints are evaluated?||4|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||tired|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|What is the study design?||Controlled Trial|
|Randomized or Non-Randomized?||NCT|
|What were the diagnostics or methods used to measure the outcome?||Subjective|
|Optional: Name of Method or short description||Profile of Mood States (POMS) Questionnaire|
|Caffeine (general)||Caffeine (general)|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||placebo/placebo exposure group in comparison to placebo/caffeine exposure group|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||NA|
|Provide a general description of results (as reported by the authors).||On the POMS, six items and two subscales were also significantly altered by the experimental conditions: ratings of Fatigue (F(3,45)=4.64, P=.007), Sluggish (F(3,45)=3.34, P=.027), Weary(F(3,45)=6.50, P=.001), Energetic (F(3,45)=5.91, P=.002), Friendly (F(3,45)=3.21, P=.032),Lively (F(3,45)=2.92, P=.049), the Vigor Scale (F(3,45)=3.72, P=.018) and the Fatigue Scale(F(3,45)=3.03, P=.039). Ratings of Fatigue and Weary were highest in the acute abstinence condition (caff/plac) (Figure 3). For ratings of Fatigue, post-hoc comparisons between drug conditions showed that caff/plac was significantly greater (P≤.05) than caff/caff and plac/caffas well as the two chronic maintenance conditions combined (caff/caff and plac/plac). For ratings of Weary, caff/plac was significantly greater (P≤.05) than plac/plac and plac/caff.Ratings of Energetic were lowest in the acute abstinence condition (caff/plac) (Figure 3), with post-hoc comparisons showing that caff/plac was significantly lower (P≤.05) than plac/plac and plac/caff as well the two chronic maintenance conditions combined (caff/caff and plac/plac).|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||No|
|What were the authors's observations re: trend analysis?|
|What were the author's conclusions?||Finally, the changes in cerebral blood flow velocity and EEG were accompanied by significant changes in subjective effects, including increased ratings of tired, fatigue, sluggish, weary and decreased ratings of energetic, friendly, lively and vigor. These subjective effects are consistent with the previously reported profile of subjective effects commonly associated with caffeine withdrawal which have been demonstrated under a wide range of methodological conditions (Juliano and Griffiths 2004).|
|What were the sources of funding?||This research was supported in part by research grant R01 DA-03890 and training grant T32-DA07209 from the National Institute on Drug Abuse.|
|What conflicts of interest were reported?||No COIs reported|
|Does the exposure (dose) need to be standardized to the SR?||No|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).|
|List all the endpoint(s) followed by the dose (mg) which will be used in comparison to Nawrot. Characterize value as LOAEL/NOAEL, etc. if possible.||Tired NOAEL = 400 mg/d Fatigue NOAEL = 400 mg/d Weary NOAEL = 400 mg/d Bushed NOAEL = 400 mg/d|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||Subjects were administered either placebo or 400 mg caffeine. Ratings for tired, fatigue, weary, and bushed were significantly lower in the placebo/caffeine group than the placebo/placebo group.|
|What is the importance of the study with respect to the adverseness of the outcome?||Important|
No baseline characteristics have been defined for this extraction form.
Results & Comparisons
No Results found.
|Arm or Total||Title||Description||Comments|
No quality dimensions were specified.
No quality rating data was found.