En rekke studier har sett på klassisk betinging av ulike typer medisiner. Kort fortalt betyr klassisk betinget placeboeffekt at en forsøksperson blir ledet til å oppleve et fordelaktig resultat. Resultatene viser at den betingede placeboeffekten gir liknende effekt som medisinene i seg selv. En viktig faktor i å oppnå betinget placeboeffekt er at forsøkspersonen har opplevd medisinsk effekt tidligere (Amanzio M, Benedetti F (1999) Neuropharmacological dissection of placebo analgesia: expectation-activated opioid systems versus conditioning-activated specific subsystems. J Neurosci 19:484–494.; Benedetti F, Pollo A, Colloca L (2007) Opioid-mediated placebo responses boost pain endurance and physical performance: is it doping in sport competitions? J Neurosci 27:11934–11939.; Goebel MU, Trebst AE, Steiner J, Xie YF, Exton MS, Frede S, Canbay AE, Michel MC, Heemann U, Schedlowski M (2002) Behavioral conditioning of immunosuppression is possible in humans. FASEB J 16:1869–1873.; Pacheco-López G, Riether C, Doenlen R, Engler H, Niemi MB, Engler A, Kavelaars A, Heijnen CJ, Schedlowski M (2009) Calcineurin inhibition in splenocytes induced by Pavlovian conditioning. FASEB J 23:1161–1167.; Benedetti F, Colloca L, Torre E, Lanotte M, Melcarne A, Pesare M, Bergamasco B, Lopiano L (2004) Placebo-responsive Parkinson patients show decreased activity in single neurons of subthalamic nucleus. Nat Neurosci 7:587–588.; Petrovic P, Kalso E, Petersson KM, Ingvar M (2002) Placebo and opioid analgesia— imaging a shared neuronal network. Science 295:1737–1740.
Betinget smertelindrende placeboeffekt er som sagt avhengig av tidligere eksponering til effektiv behandling (Colloca L, Benedetti F (2006) How prior experience shapes placebo analgesia. Pain 124:126–133.; Morton DL, El-Deredy W, Watson A, Jones AKP (2010a) Placebo analgesia as a case of a cognitive style driven by prior expectation. Brain Res 1359:137–141.), men det er også avhengig av antall ganger man har blitt eksponert(Colloca L, Petrovic P, Wager TD, Ingvar M, Benedetti F (2010) How the number of learning trials affects placebo and nocebo responses. Pain 151:430–439.; Colloca L, Miller FG (2011a) How placebo responses are formed: a learning perspective. Philos Trans R Soc Lond B Biol Sci 366:1859–1869; Colloca L, Sigaudo M, Benedetti F (2008a) The role of learning in nocebo and placebo effects. Pain 136:211–218.)
