Consciousness, Placebo Effects, and the Therapeutic Allure of Psychoneuroimmunology.

Since psychoneuroimmunology's (PNI) inception four decades ago, so-called "mind-body" approaches relying on or inspired by PNI have offered the promise of healing various ailments based on the age-old but metaphysically ambiguous principle that the mind can heal the body. How this principle is operationalized not only reveals limitations of PNI-based mind-body therapies but offers a test kit of possibilities for exploring the conceptual foundations of PNI. This article presents an integrative analysis of the role of consciousness-related phenomena (such as willful intentions, thoughts, beliefs) in their causal efficacy, examining their relationships with placebo effects and the boundaries of immune homeostatic control, as well as their therapeutic prospects. Focusing on mindfulness, the article notes how understanding the mechanisms of mindfulness, specifically those mechanisms related to consciousness and placebo effects, can lend insight into how it can validly be evaluated for effectiveness. While taking care not to overstate the role of consciousness in the control of immune homeostatic functions, this article places consciousness center stage to evaluate how mindfulness might be harnessed to modulate the immune system in a clinically relevant manner.