Hypnotizability and phobic behavior: further supporting data

Is high hypnotizability a necessary diathesis for pathological dissociation?

During the 19th century, high hypnotizability was considered to be a form of psychopathology that was inseparable from hysteria. Today, hypnotizability is considered to be a normal trait that has no meaningful relationship with psychopathology. Psychiatric patients generally manifest medium to low hypnotizability. Nevertheless, several psychiatric diagnoses are marked by an unexpectedly large proportion of patients with high hypnotizability. This is especially true of the diagnostic categories that were subsumed by the 19th-century concept of hysteria: dissociative identity disorder, somatization disorder, and complex conversion disorders. These hysteria-related modern diagnoses are also highly dissociative. A review and analysis of the literature regarding the relationship between hypnotizability and dissociation indicates that high hypnotizability is almost certainly a necessary diathesis for the development of a severe dissociative disorder. Such a diathesis has significant implications for (a) the psychiatric nosologies of the American Psychiatric Association and the World Health Organization, (b) the hypnosis field, and (c) the etiology and construct validity of dissociative identity disorder and other severe dissociative disorders. Specifically, the dissociative disorders (excepting depersonalization disorder, which is not classified as a dissociative disorder by the World Health Organization) are manifestations of hypnotic pathology.

Postural effects of imagined leg pain as a function of hypnotizability

It has been shown that, in subjects with high hypnotizability (Highs), imagined somatosensory stimulation can involuntarily activate the neural circuits involved in the modulation of reflex action. In this vein, aim of the study was to investigate whether the imagery of nociceptive stimulation in one leg may produce both subjective experience of pain and congruent postural adjustments during normal upright stance. The displacement of the centre of pressure (CoP) was studied during imagery of leg pain (LP) and during the control conditions of imagery of tactile stimulation of the same leg and of throat pain (TP) in 12 Highs and 12 low hypnotizable subjects (Lows). The results showed that the vividness of imagery was higher in Highs than in Lows for all tasks and that only Highs reported actually feeling pain during LP and TP. Congruently, during LP only Highs displaced their CoP towards the leg opposite to the one that was the object of painful imagery and increased their CoP mean velocity and area of excursion. Since the Highs' postural changes were not accounted for only by vividness of imagery and perceived pain intensity, high hypnotizability is apparently responsible for part of the postural effects of pain imagery.

Hypnotic trait and specific phobia: EEG and autonomic output during phobic stimulation

In a previous study we showed that healthy highly hypnotizable subjects, during the suggestion of a moderately unpleasant situation administered in awake conditions, exhibited a sympathetic response greatly attenuated with respect to non-hypnotizable individuals. This was interpreted as a natural protection of hypnotizable subjects against the cardiovascular effects of cognitive stress. Aim of the present study was to investigate whether the hypnotic trait is able to modulate the autonomic and cerebral activities also in specific phobic awake hypnotizable (Highs) and non-hypnotizable (Lows) subjects. Electroencephalogram, electrooculogram, electromiogram of corrugator muscle, electrocardiogram, respirogram and tonic electrodermal activity were recorded during a guided mental imagery of an animal phobic object. Phobic stimulation induced in both groups the rise of heart and respiratory frequency and the lowering of skin resistance. These changes are less pronounced in Highs than in Lows and are sustained by a different modulation of the sympatho-vagal balance. During phobic stimulation both groups exhibited a similar significant increase of EEG gamma relative power. At variance, significant stimulation-related decrements of alpha1, theta1 and theta2 activities were found only in Highs that exhibited similar changes during the control and phobic stimulation. Results suggest that hypnotizability is able to modulate cerebral and autonomic responses also in specific phobic subjects. However, the presence of a specific phobia attenuates the effectiveness of hypnotizability as a protective factor against possible stress-related cardiac illness.

The Harvard Group Scale of Hypnotic Susceptibility and related instruments: individual and group administrations

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), Tellegen's Absorption Scale (TAS); Dissociative Experiences Scale (DES); and Phenomenology of Consciousness Inventory (PCI) were administered either individually or in groups. Eighty students from undergraduate Introduction to Psychology classes were randomly assigned to 1 of the 2 administration conditions with 40 students each. Although there was a general trend of differential item difficulty levels across the 2 administration conditions, a variety of results (descriptive characteristics, reliability, and validity) point to the similarity of behavioral and subjective responses to hypnosis in the 2 conditions. The TAS, DES, and PCI also produced similar results across both conditions of administration.

Does preference for type of treatment matter? A study of exposure in vivo with or without hypnosis in the treatment of panic disorder with agoraphobia

There is evidence that preference for a given therapy may influence results. Literature also suggests that hypnotizability may be elevated in agoraphobic patients, making hypnosis a potentially powerful method for treatment. Agoraphobic patients (N = 64) were treated with either exposure in vivo or exposure combined with hypnosis in a crossover design. Half of the patients started with the treatment they preferred and the other half received the other treatment first. Although patients' preference clearly shifted in favor of the combined therapy in the course of the study, no effect of preference on outcome was evident. Although hypnotizability clearly correlated to outcome in the combined therapy, no difference in effect between the two therapies was found on behavioral, self-report, and observer measures. No additional effect of hypnosis could be shown and preference was not found to be a powerful mediator of effect.

Depersonalization and derealization during panic and hypnosis in low and highly hypnotizable agoraphobics

The primary aim of the present study was to investigate the association between spontaneous experiences of depersonalization or derealization (D-D) during panic states and hypnosis in low and highly hypnotizable phobic individuals. Secondarily, the association among level of hypnotizability, capacity for imaginative involvement, and severity of phobic complaints was also assessed. Sixty-four patients with panic disorder with agoraphobia according to the DSM-III-R (American Psychiatric Association, 1987) criteria participated in the study. Proneness to experience D-D during hypnosis was positively related to hypnotizability, but only for agoraphobic patients who had already experienced these perceptual distortions during panic episodes. Correlations of level of hypnotizability and capacity for imaginative involvement with severity of agoraphobic complaints were not significant. These findings suggest that hypnotizability may be a mediating variable between two different, although phenotypically similar, perceptual distortions experienced during panic states and hypnosis. Implications for both theory and clinical practice are discussed.

On the interaction of hypnotizability and negative affect in chronic pain. Implications for the somatization of trauma

The high risk model of threat perception predicts that high hypnotizability is a risk factor for trauma-related somatization. It is hypothesized that high hypnotizability can increase experimentally induced threat or negative affect, as measured by skin conductance level, in a linear or dose-response manner. This hypothesized interaction of hypnotic ability and negative affect was found in a consecutive series of 118 adult patients with chronic pain symptoms. Larger increases in skin conductance levels during cognitive threat were significantly related to higher levels of hypnotizability. In addition, individuals with high hypnotizability retained higher skin conductance levels than individuals with low hypnotizability after stress. The clinical implications of the interaction of hypnotizability and negative affect during threat perception and delayed recovery from threat perception are discussed in terms of cognitive mechanisms in the etiology and therapy of trauma-related dissociative disorders.

Phobias and hypnotizability: a reexamination

25 phobic Ss were administered the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) of Weitzenhoffer and E. R. Hilgard (1962). The mean SHSS:C score was 3.5 (S.D. = 2.6), which was lower than that obtained by comparison groups. The results are in direct opposition to previous results and the predictions of Frankel (1974; Frankel & M. T. Orne, 1976). Potential explanations for the discrepancy in results are discussed, including the possibility that previous studies used unrepresentative samples of phobics. It is suggested that hypnosis may sometimes play a role in the production of phobic symptoms but that other processes must be considered as well.