A multicomponent learning model of drug abuse. Drug taking and craving may involve separate brain circuits underlying instrumental and classical conditioning, respectively.

@article{Haracz1999AML,
  title={A multicomponent learning model of drug abuse. Drug taking and craving may involve separate brain circuits underlying instrumental and classical conditioning, respectively.},
  author={J L Haracz and Deborah C. Mash and Ratna Sircar},
  journal={Annals of the New York Academy of Sciences},
  year={1999},
  volume={877},
  pages={811-9}
}