Table 4.

Description of analyzed studies on arousal, according to the PICOS ¹ method.

Study	Participants	Interventions	Comparisons	Outcomes	S. Design
Barry et al. (2009) [26]	30 children; ages 8–13	Caffeine administration: 80 mg (1.3–3.3 mg/kg/day)	Caffeine vs. placebo: electrodermal activity and EEG 2 changes	Caffeine increases arousal	Randomized double blind placebo control cross-over trial
Barry et al. (2012) [27]	18 ADHD children; ages 8–13.	Caffeine administration: 80 mg caffeine	Caffeine vs. placebo: electrodermal activity	Caffeine increases arousal	Randomized double blind placebo control cross-over trial

¹ PICOS = P: participants; I: interventions; C: comparisons; O: outcomes; S: study design. ² EEG = Electroencephalogram.