The mechanisms that generate and steer the placebo response in clinical trials and clinical practice are increasingly better understood. Pavlovian conditioning of physiological responses to medication that are associated with the intake of a drug, and expectation-driven evaluation of symptoms and symptom changes by the patient after the intake of a presumed medication, contribute to symptomatic improvement as well after intake of an inert pill (placebo), as long as he/she is unaware of its nature [1]. It has also been shown that the likelihood of receiving active treatment in clinical trials modulates the placebo response [2]. Recent research has, however, shown that even the knowledge to receive a placebo will generate clinical improvements as long as the patients have had a positive experience (history) with medication and positive expectations are maintained [3]. Separating expectancy-mediated and conditioned placebo responses may be feasible in experimental research, but in clinical trials as well as in daily routine, “much like the laws of gravity, the laws of learning are always in effect” [4] and do not allow such isolation. If expectation and conditioning are ingredients of the placebo response, the quest of how to make use of them in medical practice and research arises. One precondition is to rigorously follow principles of ‘associative learning’ that were set by Ivan P Pavlov. This was realized by – among others – Robert Ader (1932–2011), a psychologist at the Rockefeller University (NY, USA) who pioneered psychoimmunology, the investigation of CNS influence and control of immunological functions using Pavlovian conditioning principles since 1975 [5]. In the 1980s, Ader had hypothesized that the placebo effects as seen in clinical studies, specifically with randomized, placebo-controlled crossover trials (a frequently used design until today), may be due to conditioning [6]. He was among the first to propose using a conditioning procedure to partially replace drugs with placebos in tandomized-controlled trials [7], and he even patented a “Method and device for administering medication and/or placebo” to test his hypotheses [101]. In an initial study, the effects of atenolol, a beta-blocker, were investigated in 24 patients with mild or moderate hypertension [6]. Patients received either placebo, followed by the drug, followed by no treatment (Group 1); or the drug, followed by placebo (Group 2); or the drug, followed by no treatment (Group 3); with each period lasting for 1 week. Prior to drug intake, Group 1 did not differ from Group 2 and 3 in the average blood pressure taken daily at home. After 1 week of drug treatment for all, blood pressure and heart rate were significantly lower in the placebo treated group (Group 2) than in the nontreatment controls (Groups 1 and 3), indicating that the placebo response was more than a residual drug effect. This is consistent with a conditioning model of the placebo effect. Such a conditioned response to placebo pills can be achieved if it is preceded by an acquisition period that is sufficiently long and effective.