title: Expectation of having consumed caffeine can improve performance and mood.
abstract: We explored whether caffeine, and expectation of having consumed caffeine, affects attention, reward responsivity and mood using double-blinded methodology. 88 participants were randomly allocated to 'drink-type' (caffeinated/decaffeinated coffee) and 'expectancy' (told caffeinated/told decaffeinated coffee) manipulations. Both caffeine and expectation of having consumed caffeine improved attention and psychomotor speed. Expectation enhanced self-reported vigour and reward responsivity. Self-reported depression increased at post-drink for all participants, but less in those receiving or expecting caffeine. These results suggest caffeine expectation can affect mood and performance but do not support a synergistic effect.
authors.affiliation: School of Psychology, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4NO, United Kingdom. l.e.dawkins@uel.ac.uk
authors.forename: Lynne
authors.initials: L
authors.lastname: Dawkins
authors.forename: Fatima-Zahra
authors.initials: FZ
authors.lastname: Shahzad
authors.forename: Suada S
authors.initials: SS
authors.lastname: Ahmed
authors.forename: Caroline J
authors.initials: CJ
authors.lastname: Edmonds
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects*; D002110:Caffeine / Q000494:pharmacology*; D003863:Depression; D004311:Double-Blind Method; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D011930:Reaction Time / Q000187:drug effects*; D057566:Self Report; D055815:Young Adult
chemical_list: D002110:Caffeine