This section of the chapter reviews studies of five promising applications of clinical hypnosis in behavioral medicine.
HypertensionIt is estimated that approximately 45% of adults in the United States have hypertension (Centers for Disease Control and Prevention [CDC], 2020). Hypertension, or high blood pressure, occurs in two stages with Stage 1 being defined as systolic blood pressure at 130 to 139 mm Hg or diastolic blood pressure at 80 to 89 mm Hg and Stage 2 being defined as systolic blood pressure greater than or equal to 140 mm Hg or diastolic blood pressure greater than or equal to 90 mm Hg (Whelton et al., 2018). Hypertension increases risk for heart disease and stroke (CDC, 2020), and nearly half a million deaths in the United States were attributable to hypertension in 2018 (CDC, 2020). Hypertension costs the United States about $131 billion each year (Kirkland et al., 2018). It is estimated that only 24% of adults who are diagnosed with hypertension have it under control (CDC, 2020); therefore, interventions to address hypertension are important.Research has examined the use of hypnosis for lowering blood pressure and targeting risk factors of hypertension such as anxiety and stress. One randomized controlled trial examined the efficacy of hypnosis for reducing mild hypertension and also whether the effect is influenced by hypnotizability and imagery skills. In this study, 30 participants were randomized to either a hypnosis or wait-list control condition. Hypnosis treatment consisted of eight weekly sessions that were 30 minutes long. A standardized relaxation induction was used and indirect suggestions of blood pressure regulation were given, but never referred directly to hypertension. Participants were encouraged to practice self-hypnosis and suggestions for self-hypnosis practice were given at the end of each session.Participants in the hypnosis condition had lowered diastolic blood pressure after 8 weeks of treatment, at a 6-month follow up, and at a 12-month follow up compared with the control condition, which had stable or slightly increased diastolic blood pressure levels (Gay, 2007). Additionally, participants in the hypnosis condition had lower systolic blood pressure levels at each time point when compared to controls (Gay, 2007). There was no significant relationship between self-hypnosis practice and blood pressure levels, and participants who practiced fewer than four times a week had blood pressure levels similar to those who practiced four or more times per week at end-point and follow-up. No significant relationships were