Patient's Placebo Effect: Understanding The Biochemical Process

While being witnessed numerous times in clinical settings the benefits of the placebo effects in patients, taking a close look at patients undergoing treatment for Parkinson’s disease, pain management and depression, very little is understood about the biochemical process that is activated by the placebo effect according to Raul de la Fuente-Fernandez and A. Jon Stoessl in their publication of “The Biochemical Bases of the Placebo Effect”. The benefits to that of the placebo effect are best defined as the patient perceives that they are being treated therefore the patients can display behaviors that suggest they are not ill at all. The placebo’s original intent was to serve as a control in clinical trials versus the potential drug being tested on other patients and no clinical trial has been done that validate the claim of its clinical importance. Placebo effect has been seen to be effective in various forms of treatment. It is hypothesized that this mindset initiates a biochemical process within the nervous system that involves limbic circuitry and the release of dopamine that can lead to observed clinical improvement, even to patient who did not receive an actual drug. Evidence has shown that the belief that patients are getting effective treatment helps their condition clinically improve. Stoessl and de la Fuente-Fernandez have gathered results from numerous studies, including past research of their own, in this review article to support the claim of the placebo effect being essential to beginning of the biochemistry of healing with the body (de la Fuente-Fernandez and Stoessl, 2004).

Scientist have been able to determine an important psychological aspect is need in order to start the biochemical role involved with the placebo effect however, what scientist are not completely sure what the biochemical process is. After taking a close look at studies involving Parkinson’s disease, depression and pain, there has been evidence from positron emission tomography (PET) to prove that structures of the limbic system are involved in the biochemistry of the placebo effect which include cortical areas and subcortical nuclei. A major role of the limbic system is to regulate emotions and reward circuitry. Such emotions include fear, anxiety, anger and sorrow. Emotions that can be associated with conditions like depression and Parkinson’s disease. The authors also address another theory that one’s ability to move has relation to one’s mood along with correlation of Parkinson’s patients and depression, but they highlight the important findings of limbic system via PET and the placebo effect. Further studies reveal that the limbic system is the setting of the placebo effect when the reward system and the function of dopamine is also observed (de la Fuente-Fernandez and Stoessl, 2004).

Attention is also given to the correlation of placebo effect and placebo analgesia by de le Fuente-Fernandez and Stoessl from their gatherings of studies involving pain and depression. Both conditions which have been seen associated to one another. The importance of placebo analgesia has been valued by clinicians for years and the connection of the placebo effect to biochemistry was first discovered though the study of pain disorders. Since then evidence from studies of placebo analgesics show that it is mediated by endogenous opioids found within the brain that involve the reward system. This brings scientists to the theory that dopamine plays a major within the limbic system based on factual evidence that opioids and placebo analgesics increase activity in the cortical and subcortical areas (limbic system) that are known to receive dopamine projections. Dopamine is essential for motor function. Without it there is decrease in speed of movement and muscle rigidity, common symptoms found in Parkinson’s patients. Oddly enough, through the placebo effect patient with normal decreased levels of dopamine have been seen to have increased levels during treatment with the placebo. The placebo effect in depression studies also contribute to dopamine being a key molecule. The authors describe depression as “a failure in reward mechanisms” since dopamine is involved in transmitting reward signals to the limbic system. As seen with Parkinson’s disease, patient express actions and words similar to those without a mood disorder under the placebo effect thus showing a correlation between placebo effect and the reward circuitry. There is an expectation of reward that causes a release of dopamine is the principle hypothesis in pain studies. The relation between pain, depression and Parkinson’s is the limbic system acting as the neuroanatomical substrate for all these conditions (de la Fuente-Fernandez and Stoessl, 2004).

The placebo should be considered a subject that falls under the category of biopsychology. John Pinel defines biopsychology as a study of neuroscience that pertain to the focus of brain and behavior relationships that acts as the connection of psychology to neuroscience in his publications about biopsychology (Pinel). If the placebo effect starts a neurophysiological process in the brain that has a direct consequence to the patient’s behavior and health status then reveals the placebo effect is related to biopsychology and in the future could be used as a regular healthcare practice (de la Fuente-Fernandez and Stoessl, 2004).

Psychological aspects initiate the biochemical process of the placebo in order for patients to benefit from the placebo effect. It is known that the biochemical bases of this phenomenon involves limbic circuitry and dopamine is suspected to be a key molecule in the process but the exact mechanism of action of the brain is unknown (de la Fuente-Fernandez and Stoessl, 2004). Future hopes are that neuroscientist will be able to describe what takes place from a neurophysiological standpoint in the future so that information can be used to help find a cure for Parkinson’s disease or depression. Perhaps an ultimate solution to pain management can be found that does not result in addiction or substitution of drugs. The possibilities of what can be accomplished are endless as we discover the unique design and function of the human brain.