Caffeine reinforcement demonstrated in a majority of moderate caffeine users.

@article{Evans1994CaffeineRD,
  title={Caffeine reinforcement demonstrated in a majority of moderate caffeine users.},
  author={S. M. Evans and T S Critchfield and R G Griffiths},
  journal={Behavioural pharmacology},
  year={1994},
  volume={5 3},
  pages={231-238}
}
A mutually exclusive choice procedure was used to evaluate the reinforcing effects of caffeine in eleven normal subjects with histories of regular caffeine consumption (mean 256mg/day). Subjects participated for 24 weeks; each week consisted of three consecutive daily sessions (two sampling days followed by a choice day) during which subjects were required to abstain from dietary sources of caffeine. On each sampling day subjects ingested four capsules, one every 2h. Capsules contained placebo… CONTINUE READING