Placebo, meaning, and health.

Placebos are boon and bane to medical theory and clinical practice. On the one hand, randomized controlled trials employ concealed allocations of placebo to control for effects not due to specific pharmacological mechanisms. As a result, nearly all of evidence-based medicine derives from principles and practices based on placebo. On the other hand, medical researchers and physicians have tended to ignore, minimize, or deride placebos and placebo effects, perhaps due to values emphasizing scientific understanding of mechanistic pathways. We argue that intention, expectation, culture, and meaning are central to placebo-effect phenomena and are substantive determinants of health. We introduce three dualities that are integral to placebo/meaning phenomena: body-mind, subconscious-conscious, and passive-active. These placebo-related dualities should be acknowledged, explored with research, and incorporated in theory. While we view consideration of placebo and meaning effects as essential to any adequate understanding of human health, we feel that lessons from this area of inquiry may already provide practical tools for astute clinicians. Toward this end, we list eight specific clinical actions: speak positively about treatments, provide encouragement, develop trust, provide reassurance, support relationships, respect uniqueness, explore values, and create ceremony. These clinical actions can empower patients to seek greater health and may provide a healthful sense of being cared for.