Effects of L-theanine-caffeine combination on selective attention in adolescents with ADHD: a double-blind placebo-controlled crossover study

A controlled trial tested L-theanine-caffeine combination versus methylphenidate and placebo in 21 adolescents with ADHD using a visual attention task and EEG recording. L-theanine-caffeine reduced false alarms compared to placebo but did not improve reaction time or discrimination sensitivity, whereas methylphenidate showed broader benefits across attention measures.