Use of hypnosis in studies of the effect of stress on cardiovascular function and hormones

In an attempt to separate the somatic and mental components of stress, groups of young male volunteers underwent running exercises and sauna baths, and roughly one year later had the same experiences recalled under hypnosis. In addition, experiments involving mental stress in the form of mental arithmetic were performed. A variety of physiological and biochemical parameters was measured on each occasion. Results for cardiovascular responses, renin-angiotensin-aldosterone, cortisol, testosterone, androstenedione, prolactin and growth hormone are reported. It is concluded that the mental component of combined mental and somatic stress may be separated from the somatic component by hypnotic suggestion. The response during hypnotic suggestion of the stress is usually of less but sometimes of the same magnitude as that obtained during the actual stress. Occasionally the response goes in the opposite direction during hypnotic suggestion as compared to the real situation. The individual responses vary considerably between individuals. The hormones most sensitive to mental stress are growth hormone, androstenedione, cortisol, renin and angiotensin II. In the present study, mental stress had a depressing effect, if any, on plasma prolactin. Hypnosis in itself has no effect on plasma hormones in unstressed subjects compared to the normal diurnal variations.