PLACEBO EFFECTS CONTINUE AFTER DRUG ADMINISTRATIONS HAVE CEASED
Benedetti, F., Pollo, A., & Colloca, L. (2007). Opioid-mediated placebo responses boost pain endurance and physical performance: is it doping in sport competitions? Journal of Neuroscience, 27, 11934-11939.
"The neurobiological investigation of the placebo effect has shown that placebos can activate the endogenous opioid systems in some conditions. So far, the impact of this finding has been within the context of the clinical setting. Here we present an experiment that simulates a sport competition, a situation in which opioids are considered to be illegal drugs. After repeated administrations of morphine in the precompetition training phase, its replacement with a placebo on the day of competition induced an opioid-mediated increase of pain endurance and physical performance, although no illegal drug was administered. The placebo analgesic responses were obtained after two morphine administrations that were separated as long as one week from each other. These long time intervals indicate that the pharmacological conditioning procedure has long-lasting effects and that opioid-mediated placebo responses may have practical implications and applications. For example, in the context of the present sport simulation, athletes can be preconditioned with morphine and then a placebo can be given just before competition, thus avoiding administration of the illegal drug on the competition day. However, these morphine-like effects of placebos raise the important question whether opioid-mediated placebo responses are ethically acceptable in sport competitions or whether they have to be considered a doping procedure in all respects".
Implication. Placebo effects are manifested by beliefs. Some individuals will react with "appropriate symptomatic behaviors" while never having had pre-conditioning trials with an actual drug. The role of placebo effects, socially termed as an aberration of the self-fulfilling prophecy phenomenon, rarely is considered as an option for coaching and performance-enhancement. Any use of such a technique would not be cheating because it solely involves the belief-system of the individual.