Study Title and Description
Mood and Psychomotor Tremor Changes following Acute Caffeine Consumption in Moderate and Minimal Caffeine Consumers
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||Mood and Psychomotor Tremor Changes following Acute Caffeine Consumption in Moderate and Minimal Caffeine Consumers|
|Author||H. R. Sands, L. A. Downey, R. P. Wilson, L. R. Abbott, B. Tysse and A. C. Parrott|
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)?||The current placebo-controlled balanced-crossover study aimed to investigate the acute effects of caffeine on mood and psychomotor performance in both moderate consumers and minimal/nonconsumers of caffeine.|
|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)||Following overnight caffeine abstinence (approximately 12 hours), 15 moderate consumers (mean 316.2 mg/day) and 14 minimal/nonconsumers (mean 37.07 mg/day) received a beverage containing either 150 mg caffeine or a matched placebo at ‡ 48 hours apart. Mood and psychomotor assessments were carried out at baseline and 30 minutes postdrink. Bond–Lader visual analogue scales (VAS) and caffeine research VAS were used to assess mood, while three simple motion tasks (using an accelerometer device to record dynamic bodily movement) were used to assess psychomotor control. Caffeine research VAS. A further six VAS—‘‘relaxed,’’ ‘‘alert,’’ ‘‘jittery,’’ ‘‘tired,’’ ‘‘tense’’ and ‘‘headache’’— were presented.32 Participants rated their current subjective status for each of the descriptors by placing a mark on a 100-mm line with the end points labeled ‘‘not at all’’ (left) and ‘‘extremely’’ (right). Alert and tired ratings were combined (as previously recommended)32 to give a composite ‘‘alertness’’ rating, and tense and relaxed were combined to give a composite ‘‘tension’’ score.|
|How many outcome-specific endpoints are evaluated?||3|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||Tension|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|Notes||Study also measured alertness which was a combined measure including alert and tired components.|
|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||Caffeine research VAS. A further six VAS—‘‘relaxed,’’ ‘‘alert,’’ ‘‘jittery,’’ ‘‘tired,’’ ‘‘tense’’ and ‘‘headache’’— were presented.32 Participants rated their current subjective status for each of the descriptors by placing a mark on a 100-mm line with the end points labeled ‘‘not at all’’ (left) and ‘‘extremely’’ (right). Alert and tired ratings were combined (as previously recommended)32 to give a composite ‘‘alertness’’ rating, and tense and relaxed were combined to give a composite ‘‘tension’’ score.|
|Caffeine (general)||Caffeine (general)|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||Two drinks containing 0 mg (cornflour placebo) vs 150 mg of Caffeine Anhydrous BP|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||None listed.|
|Provide a general description of results (as reported by the authors).||Mean predose baseline scores and CFB scores for both treatment conditions for each mood factor are displayed in Table 3. A higher score indicates a higher rating of each mood factor. Two-way ANOVAs (group [moderate or minimal consumers] · treatment [caffeine/placebo]) revealed composite ratings of alertness increased significantly more following caffeine consumption than placebo [F (1, 27) = 4.77, p < 0.05, gp2 = 0.15], as did participants ratings of jitteriness [F (1, 27) = 6.36, p < 0.05, gp2 = 0.15]. Neither of these treatment effects revealed a significant interaction with group ( p > 0.05) or group difference. Furthermore, no significant changes in composite tension ratings or headache ratings were observed between treatments.|
|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?||The results of the present study suggest caffeine does exert psychoactive effects over elements of both mood and psychomotor control; however, this effect was generally irrespective of group, providing evidence against the withdrawal reversal hypothesis of caffeine consumption. The mood results are suggestive of an absolute increase in alertness and jitteriness and decrease in calmness—independent of group. The present results also support previous findings of induced anxiety following caffeine consumption; however, previous studies had suggested a higher dose (400–600mg) was necessary for anxiogenic effects to be seen, whereas the present study suggests 150mg is enough for these effects to surface. The increased jitteriness also supports previous findings 32,34; however, previous studies have also found an interaction of treatment and group (e.g., Ref.34). Although no significant interaction was found in the present study, the means trend does suggest that nonconsumers report a higher increase in jitteriness than consumers. From the mean mood rating results, we can also observe that the minimal/nonconsumers rated themselves to be higher in ‘‘tension’’ following consumption of both caffeine and placebo. Nehlig8 suggested that those who do not habitually consume caffeine are often more sensitive to the anxiogenic and psychostimulant effects; thus, the tension results here may reflect an uncertainty of condition and a worry about subsequent sensitive responses. Nonconsumers also display a larger decrease in ‘‘calmness’’ than consumers, which supports this notion, although it must be noted that these group differences were not statistically significant.|
|What were the sources of funding?||None listed.|
|What conflicts of interest were reported?||None listed.|
|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.||Tension- NOAEL = 150 mg Jitteriness - LOAEL = 150 mg Headache - NOAEL = 150 mg|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||single dose Anxiogenic effects are seen at lower doses than reported in the literature|
|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.