Impaired hemodynamic activity in the right dorsolateral prefrontal cortex is associated with impairment of placebo analgesia and clinical symptoms in postherpetic neuralgia.

•Patients with chronic pain due to postherpetic neuralgia (PHN) were used.•Hemodynamic activity in the dorsolateral prefrontal cortex (dlPFC) was analyzed.•PHN showed less placebo effects and smaller hemodynamic responses in the right dlPFC.•PHN symptoms were associated with smaller placebo effects and right dlPFC responses.•Deficits in placebo effects due to dlPFC disturbance are involved in chronic pain.