Placebo Effect ▶ Placebo Placebo Response ▶ Placebo Placement - Pending Requirement ▶ Stay - Put Requirement Placenta

A simulated intervention (often a drug but potentially other interventions) used as a control/comparison in research studies. As suggested in the title of a book on the subject (Shapiro & Shapiro, 2000), the effects of such treatment can be powerful (what is termed to placebo response or effect). In drug studies, for example, the use of a placebo (inert agent that is packaged so as to be indistinguishable from the drug being studied) control provides one of the most stringent tests in demonstrating drug efficacy. As Volkmar and Wiesner (2009) note that the nature of the placebo response in studies involving children with autism reflects several factors: high levels of attention from parents, teachers, and clinicians; provision of high-quality care during a study; variation in symptoms over time; and the effects of expecting a change with a new treatment (see also Volkmar, 2001). The effects of placebo treatments can be quite strong, as demonstrated in studies of secretin which did not significantly outperform secretin (Sandler & Bodfish 2000); on the other hand, studies of agents like risperidone (McCracken et al., 2002), the active drug, proved significantly better than placebo even after only a few weeks of administration.