The Roles of Endogenous Opioids in Placebo and Nocebo Effects: From Pain to Performance to Prozac

Placebo Effect: The Stem of Seminal Studies with Active Treatment Neurobiological Mechanisms, And Implications for Parkinson’s Disease with Deep Brain Stimulation

“…Since rostral anterior cingulate cortex and brainstem are involved in regulating opioid analgesia, increased activity in contralateral thalamus, the insula bilaterally and the caudal AAC can also be found in this part by utilizing positron emission tomography (Willoch et al, 2000;Petrovic, 2002). In the study of cerebral blood flow in comparison to the opioid analgesia responses, the involvement of placebo and opioid receptors and brainstem regions has revealed that placebos have the possibility of triggering the bodily opioid mechanisms which provide the sense of pain relief and the release of neurotransmitters such as dopamine and endorphin (Ortega et al, 2022;Kerr & Gregg, 2024). In Petrovic's trials, μ-opioid receptor agonist remifentanil on regional cerebral blood flow synchronized with the effect of placebos.…”