Methylphenidate and cocaine have a similar in vivo potency to block dopamine transporters in the human brain

Nora D. Volkow, Gene Jack Wang, Joanna S. Fowler, Marian Fischman, Richard Foltin, Naji N. Abumrad, Samuel J. Gatley, Jean Logan, Cristopher Wong, Andrew Gifford, Yu Shin Ding, Robert Hitzemann, Naomi Pappas