How well do someone’s personality or genetics relate to their responsiveness to placebo effects?

Placebo analgesia in heat pain was induced with 7 different learning manipulation combinations (verbal suggestions, classical conditioning, social learning) or none (control). 208 healthy participants were randomized across 1 of 8 conditions. Personality traits were assessed with the Life Orientation Test–Revised (LOT-R), Eysenck Personality Questionnaire (EPQ), Penn-State Worry Questionnaire (PSWQ), Interpersonal Reactivity Index (IRI), and the Somatosensory Amplification Scale (SSAS). The three different SNPs were examined by collecting saliva cells and analyzing DNA with next-generation sequencing.