Expectations and Sequelae to Hypnosis: Initial Findings

Abstract

As part of the introduction to an experiment using the Harvard Group Scale, subjects were given one of three brief instructions before being hypnotized: (1) no mention of negative or positive aftereffects, (2) vague warning of negative aftereffects, i.e., "some mildly unpleasant experiences", plus, "most persons report their experiences to be pleasurable and interesting", (3) specific warning of negative aftereffects, i.e., "approximately one half subjects have reported mild, short-term aftereffects such as headache", etc. (no positive information). The "specifically warned" Ss showed more negative aftereffects than both of the other groups, and the "no mention" Ss showed more than the "vaguely warned" Ss. The positive suggestions in the "vaguely warned" Ss instructions may have confounded the expectation for negative effects. A follow up study used instructions varying only in the degree of expectations for negative aftereffects (no mention of positive aftereffects). The results did not show group differences in negative aftereffects as predicted, however, correlational results suggested some interesting interactions among subject variables and the type of prehypnotic instructions administered.

Hypnotizability and Somatic Complaints:A Gender-Specific Phenomenon

“…Roughly 3% of research participants may experience adverse effects, although scales using more cognitive (Stanford Hypnotic Susceptibility Scale, Form C; SHSS:C; Weitzenhoffer & Hilgard, 1962) than ideomotor (Harvard Group Scale of Hypnotic Susceptibility, Form A; HGSHS:A; Shor & Orne, 1962) items may cause a much higher incidence of somatic aftereffects (Crawford, Hilgard, & Macdonald, 1982;Page & Handley, 1993). Some evidence also suggests prehypnosis expectations predict aftereffects on the HGSHS:A (Coe, Peterson, & Gwynn, 1995). Hypnotizability, therefore, has been shown to predict somatic complaints following a hypnosis session, with high hypnotizability being associated with more aftereffects (Page & Handley, 1993.…”

Identifying Hypnotic Sequelae: The Problem of Attribution

“…However, previous research in our laboratory (Page & Handley, 1993) has shown that taking a few simple precautions did significantly reduce the frequency of long-term effects, although the overall incidence of effects (both short-and long-term) was not significantly reduced, These precautions were: a brief lecture dispelling some myths about hypnosis; telling participants that no psychological treatment would be undertaken, and eliminating all references to aftereffects (e.g., the mention of headache) in a standard susceptibility scale. The wisdom of employing at least the last of these precautions has been confirmed by a recent study (Coe, Peterson, & Gwynn, 1995) that demonstrated even warnings in informed consent forms may in part determine the number and kind of negative sequelae that are reported. It should be noted that the problem of informed consent itself possibly producing negative sequelae would not be unique to hypnosis, but extends to psychological and even medical research in general.…”