Hypnosis, response expectancy and migraines and tension-type headaches: 'They can because they think they can: how would it be if you imagined it to be?'

SECTION A
Response expectancies have been suggested to mediate hypnosis intervention outcomes. This review examined relevant studies to determine the quality of evidence for this proposed association. A systematic search produced ten studies that fulfilled inclusion criteria. The review provided some evidence for an association between response expectancy and mediation of hypnosis outcomes. However, study quality, generalisability and evidence for mediation were mixed. Further controlled trials of hypnosis-based interventions with varied clinical populations are needed to validate response expectancy as a mediator of hypnosis outcomes.

SECTION B
The methodological rigour of studies examining the effects of hypnosis upon migraines and tension-type headaches has been limited. This study developed and evaluated a single online- group session plus self-hypnosis intervention for this population. People with diagnoses of migraines or tension-type headaches (N = 35) participated in a pilot randomised controlled trial. The hypnosis group demonstrated significantly greater decreases in mean daily headache ratings and increases in medication-free days at four-week follow-up compared with waitlist-controls. Outcomes were not moderated by expectancy, attitudes to hypnosis, suggestibility or mediated by post-intervention changes in expectancy. Secondary improvements in depression, wellbeing, self-efficacy and internal-locus-of-control were not observed. Findings are discussed and future research recommendations provided.