Placebo accounts for significant portions of clinical outcomes in many illnesses. Neural correlates of placebo response is increasingly subjected to research.Physician interaction is a key element of placebo response. Placebo response is associated with changes in certain areas in brain.One previous study has shown that effective psychiatrists can augment placebo as well as drug effect ( Mackay 2006). It would be interesting to see neural correlates of doctors during treatment as it is thought that social interaction may be promoted by mirrored brain activations between individuals. Would the act of administration of pain relief to the patient lead to increased activations in physician’s own brain regions that have been suggested to be implicated in expectancy for pain relief, such as the right ventrolateral prefrontal cortex (VLPFC)?
This fMRI study scanned physician’s brain while they were having direct face-to- face interaction with a patient and perform a pain treatment paradigm. 18 physicians participated in the study along with simulated patients. Physicians were introduced to a thermal pain stimulator and rated the pain on a scale. Then, they were introduced to the sham analgesic device and this was introduced in such away that physicians experienced less pain when this was on. Physicians then performed a 20 mt structured physical examination.After the clinical examination, physicians were placed in the scanner for an individual pain scan. The heat probe was placed on the physicians’ left arm and a 10-min scan was performed during intermittent high-pain and low-pain stimuli. Then, the patient was led into the scanner room. The heat probe was taken from the physician and placed on the patient’s arm instead. There were three experimental conditions; ‘treatment’, ‘no-treatment’ and ‘control’. During ‘no-treatment’, patient received high intensity pain while the physician was prompted to press the dummy button, knowing there was no pain relief. The patient reacted with a high-pain facial expression during the 12 s of heat administration. During the ‘treatment’ condition, the physician was prompted to activate the analgesic device while believing that the patient was receiving the same high intensity heat. Based on the proven effectiveness of the analgesic device, the patient reacted with a neutral facial expression, giving the impression that the treatment was successful. The third condition was a control task, in which the physician was prompted to press the dummy button while informed that no heat was administered, resulting in a neutral observation of the patient.
The initial fMRI scan, in which calibrated thermal pain was administered to the physicians, several regions of the cerebral pain network were activated including the bilateral insulae, cingulum and secondary somatosensory cortex.
Physicians, while treating patients, activate the right VLPFC. This region has been implicated in placebo responses. This region may represent expectancy for relief by exerting control over brain circuitries with neuro chemical resources to modulate pain.
The perspective-taking score is an independent measure of the ability to imagine how things look from another person’s perspective. ( ie cognitive aspect of empathy) .Physicians with high perspective-taking skills were more likely to activate the rACC (rostral anterior cingulate cortex) ( associated with processing of reward and subjective value) during ‘treatment’ and thus simulate the patient’s pain relief. rACC is also implicated in the coding of value and might therefore be a correlate of the physicians motivation to treat during the treating task.
Physician treatment involves neural representations of treatment expectation, motivation, reward processing and empathy.
Interaction between physician and patient responses ( matching/ augmenting etc) might be crucial in the final outcome of placebo response.This needs to studied further.
Summary of the article:
Sharing pain and relief: neural correlates of physicians during treatment of patients.Jensen KB, Petrovic P, Kerr CE, Kirsch I, Raicek J, Cheetham A, Spaeth R, Cook A, Gollub RL, Kong J, Kaptchuk TJ. Mol Psychiatry. 2014 Mar;19(3):392-8.