title: Neuromodulation of conditioned placebo/nocebo in heat pain: anodal vs cathodal transcranial direct current stimulation to the right dorsolateral prefrontal cortex.
abstract: Placebo and nocebo play an important role in clinical practice and medical research. Modulating placebo/nocebo responses using noninvasive brain stimulation methods, such as transcranial direct current stimulation (tDCS), has the potential to harness these effects to therapeutic benefit in a clinical setting. In this study, we assessed the effect of anodal and cathodal tDCS over the right dorsolateral prefrontal cortex (rDLPFC) on conditioned placebo/nocebo cue response to heat pain. Two matched groups of healthy volunteers were subjected to an identical session of conditioning, during which low and high cues (abstract images) were associated with low and high pain levels, respectively. Twenty-minute 2-mA tDCS (either anodal or cathodal) over the rDLPFC was applied. The influence of tDCS current polarity (anodal vs cathodal) on placebo and nocebo was assessed, using subjects' pain ratings in response to identical pain preceded by the conditioned high or low cues. The duration of cue presentation varied to allow either fully conscious or subliminal processing. Significant placebo and nocebo effects in the anodal but not the cathodal group were elicited with the conditioning paradigm. This study provides evidence of a possibility to modulate the conditioned placebo and nocebo effect by changing the excitability of the rDLPFC using tDCS.
authors: Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA, USA Department of Psychiatry Harvard Medical School, Boston, MA, USA Department of Psychology, National University of Singapore, Singapore, Singapore MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA.
authors: Natalia
authors: N
authors: Egorova
authors: Rongjun
authors: R
authors: Yu
authors: Navneet
authors: N
authors: Kaur
authors: Mark
authors: M
authors: Vangel
authors: Randy L
authors: RL
authors: Gollub
authors: Darin D
authors: DD
authors: Dougherty
authors: Jian
authors: J
authors: Kong
authors: Joan A
authors: JA
authors: Camprodon
mesh_terms: D000328:Adult; D003213:Conditioning, Psychological / Q000502:physiology*; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D008297:Male; D064786:Nocebo Effect; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement / Q000379:methods / Q000523:psychology*; D010775:Photic Stimulation / Q000379:methods; D015990:Placebo Effect; D017397:Prefrontal Cortex / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D055815:Young Adult