Clinical implications and applications of placebo effects: potential for post-operative pain management

• Applicant: Privatdozentin Dr. Regine Klinger
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 138279939

Analgesic placebo effects are present in healthy persons as well as in patients. Classical conditioning and processes of expectation were investigated as basic mechanisms. Previous studies were predominantly conducted in experimental treatment settings. The studies conducted during the first funding phase illustrated that patients with chronic back pain showed a significant placebo-induced reduction in back pain and a significant increase in the flexibility of their movements. Participants with negative prior experience showed better treatment effects through manipulation by conditioning than by expectation and a more positive expectation towards analgesic medication was related to a higher placebo response. These results suggest the use of the analgesic placebo effect in clinical practice. The aim of the second funding period is to exploit placebo mechanisms to improve the outcome of post-operative pain management. In this study, we will not investigate placebo analgesia solely induced by placebo but rather the additive placebo component, which is an inherent part of each medication in addition to the pharmacological component. The study will examine 90 participants treated after surgery for artificial knee or hip joint replacement in an acute inpatient ward. They will be randomly allocated to three groups: 1. ‘Hidden medication group’ (standard post-operative analgesic medication), 2. ‘Open medication’ (standard post-operative analgesic medication in combination with optic and haptic cues pointing to the pain medication [labeling]). 3. ‘Maximized open medication’ (standard post-operative analgesic medication in combination with optic and haptic cues pointing to the pain medication (labeling) and additional verbal instruction and interaction with the experimenter). It is expected that group 2 and 3 will yield a superior pain reduction compared to group 1 and that group 3 will show a higher pain reduction than group 2. The results could have immediate clinical relevance for post-operative pain management.

• DFG Programme: Research Units
• Subproject of: FOR 1328: Expectation and Conditioning as Basic Processes of the Placebo and Nocebo Response
• Participating Person: Professorin Dr. Herta Flor