Placebo–Placebo, Nocebo–Nocebo, Placebo–Nocebo, and Nocebo–Placebo Effects: A Review of Eastern and Western Perspectives

Abstract

This study examined placebo and nocebo effects, characterized by classical conditioning, operant conditioning, and expectancy effects. The placebo–placebo and nocebo–nocebo effects can be categorized to function independently, including the influence of various factors such as pill color, size, genetics (including other biological factors), branding, the demeanor of healthcare providers, and treatment settings and also considering beyond science understandings (spiritual perspective). To enhance understanding and optimize treatment outcomes, these effects can be categorized under classical conditioning, operant conditioning, and expectancy effect as follows in dominating pre-dominants of nature and beliefs ranging in the respective involuted evolutionary probability of occurrence: 1) placebo–placebo effect, driven by optimistic nature and belief leading to pure placebo effect which can be divided into double placebo and yogic placebo effect; 2) nocebo–nocebo effect, influenced by a pessimistic nature and belief leading to pure nocebo effect which can be divided into double nocebo and vamamarya nocebo effect; 3) placebo–nocebo effect, where optimism nature counters pessimistic belief, resulting in a impure placebo effect; and 4) nocebo–placebo effect, where pessimistic nature undermines optimistic belief, leading to a impure nocebo effect; understanding that not an individual will go through only one of the categories discussed here. It is recommended that future studies adopt this categorization and consider adjusting the definitions of placebo and nocebo to accommodate Eastern and Western (Universal) perspectives.