Hypnotic Susceptibility, or F-bias: Its Relevance to Eating Disorders

Hypnosis research and theory has recently paid increasing attention to hypnotizability as a trait in its own right and to a convergence with ideas in neuropsychology. Hypnotizability, or F-bias, may be broadly characterized as involving focused attention, flexibility in switching cognitive styles and the activity of frontal cortical systems. F-bias/hypnotizability correlates with a number of activities other than hypnotic performance, one of which is disordered eating behaviour. Within the clinical literature the general finding has been that restricting anorexics are of normal or slightly above normal hypnotizability whereas bulimics are very significantly above normal hypnotizability and show increased dissociative tendencies. In normal weight non-clinical populations also there is also a positive correlation between hypnotizability, dissociative tendencies and attitudes to food intake. A recent study looked at both dissociation and hypnotizability in relation to disordered eating, as measured by an eating questionnaire, in a normal weight female undergraduate population. The data confirmed that those with bulimic tendencies scored higher on both hypnotizability and dissociation. The results also showed that hypnotizability was specifically related to a factor of dietary restraint, whereas dissociation was related to a factor of impulsive eating. The latter may account for the binge components of disordered eating. In contrast to earlier views, which tended to equate hypnotizability and dissociative tendencies, these data suggest that they are independent factors which influence different aspects of eating behaviour. Other work is described, which indicates that restrained eaters are more responsive than non-restrained eaters to suggestions of increased body size, which may account in part at least for the distortions of body image seen in clinical eating disorders. The ways in which both hypnotizability and dissociative tendencies might operate as independent moderators in a sociocultural model of the development of anorexia and bulimia nervosa are