Di questi uno studio presenta, inoltre, un
balanced placebo design (28), in cui lo stesso gruppo di soggetti viene sottoposto a 4 differenti condizioni (suggestione sostanza attiva-somministrazione sostanza attiva, suggestione sostanza attiva-somministrazione placebo, suggestione placebo-somministrazione sostanza attiva, suggestione placebo-somministrazione placebo).
Studies employing a balanced placebo design to examine the effects of alcohol consumption often report that the non-alcoholic placebo beverage used was credible as an alcoholic drink.
Studies often employ a balanced placebo design (Hull and Bond, 1986), where a low or nonalcoholic beverage serves as a control treatment, allowing for the effects of an alcohol intervention to be compared against a control.
Foad et al., (2008) used the balanced placebo design (Marlatt and Rohsenow, 1980) in an attempt to quantify the respective pharmacological and psychological contributions to the ergogenic effects of caffeine in 40-km cycling performance.
(1980) Cognitive approaches in alcohol use: Expectancy and the balanced placebo design. In: Advances in substance abuse: Behavioural and biological research.
* A variation on the balanced placebo design is used, along with a within-subjects design, in order to estimate the effects of conditioned tolerance and expectancy, compared to unconditioned alcohol responses and a control placebo condition.
Although the sample is not large enough to do a complex regression analysis, we will present comparisons of the different conditions of the balanced placebo design. Correlations among predictor variables and selected dependent variables will also be presented.