Table 8.

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

Study	Participants	Interventions	Comparisons	Outcomes	S. Design
Whalen et al. (2008) [42]	53 children and adolescents (30 with major depressive disorder); ages 7–17	Caffeine intake questionnaires; structured diagnosis interviews	Caffeine vs. no caffeine: structured diagnostic interviews differences	Higher caffeine intake in major depressive disorder	Clinical evaluation longitudinal study
Luebbe and Bell (2009) [43]	135 children aged 10–12; 79 adolescents aged 15–17	Frequency of consumption questionnaire of caffeine; depression inventory for youth; treatment of anxiety inventory for children	Low and high caffeine consumption: mood differences	Young children who consume higher doses proportionally to weight are more sensitive to caffeine	Cohorts
Benko et al. (2011) [44]	51 children; aged 9–12	Nutrition-behavior inventory; depression inventory for youth; child behavior checklist	Low vs. high caffeine intake: mood differences	Caffeine increases depressive symptoms	Longitudinal

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