FIG. 1.

Placebo neurobiology. Placebo responses are initiated through higher-order cognitive and affective processes occurring in the dorsolateral prefrontal cortex (dlPFC), orbitofrontal cortex (OFC), and anterior cingulate cortex (ACC). They are next propagated through dopaminergic reward systems in the ventral striatum (VS). Placebos ultimately trigger various end-organ effects, including modulation of endogenous opioids, dopamine, serotonin, sympathetic nervous system (SNS) activity and cortisol.