ABSTRACT
The psychometric structure of the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was tested in a Rasch analysis using data from 279 subjects. The Rasch model is the model of choice because it justifies the use of the sum of the item scores as a measure for the underlying construct. Rasch analysis revealed that use of a single sum score (number of suggestions passed) to express hypnotic ability is not sufficiently justified. However, the omission of the mosquito-hallucination and anosmia items (Items 3 and 9) rendered this short 10-item form of the SHSS:C sufficiently compatible with requirements of one-dimensionality, local stochastic independence,and equi-discriminability. Hence, the 10-item form justifies use of a sum score.
Subject(s)
Hypnosis , Personality Assessment/statistics & numerical data , Psychometrics/statistics & numerical data , Suggestion , Factor Analysis, Statistical , Humans , Models, Statistical , Observer Variation , Reproducibility of Results , Stochastic Processes , Students/psychologyABSTRACT
OBJECTIVE: Despite the fact that the assumption of a relationship between conversion disorder and childhood traumatization has a long history, there is little empirical evidence to support this premise. The present study examined this relation and investigated whether hypnotic susceptibility mediates the relation between trauma and conversion symptoms, as suggested by Janet's autohypnosis theory of conversion disorder. METHOD: A total of 54 patients with conversion disorder and 50 matched comparison patients with an affective disorder were administered the Structured Trauma Interview as well as measures of cognitive (Dissociative Experiences Scale) and somatoform (20-item Somatoform Dissociation Questionnaire) dissociative experiences. RESULTS: Patients with conversion disorder reported a higher incidence of physical/sexual abuse, a larger number of different types of physical abuse, sexual abuse of longer duration, and incestuous experiences more often than comparison patients. In addition, within the group of patients with conversion disorder, parental dysfunction by the mother-not the father-was associated with higher scores on the Dissociative Experiences Scale and the Somatoform Dissociation Questionnaire. Physical abuse was associated with a larger number of conversion symptoms (Structured Clinical Interview for DSM-IV Axis I Disorders). Hypnotic susceptibility proved to partially mediate the relation between physical abuse and conversion symptoms. CONCLUSIONS: The present results provide evidence of a relationship between childhood traumatization and conversion disorder.
Subject(s)
Child Abuse, Sexual/psychology , Child Abuse/psychology , Conversion Disorder/psychology , Adult , Child , Child Abuse/diagnosis , Child Abuse, Sexual/diagnosis , Child of Impaired Parents/psychology , Conversion Disorder/diagnosis , Dissociative Disorders/diagnosis , Dissociative Disorders/psychology , Female , Humans , Hypnosis , Incest/psychology , Male , Middle Aged , Personality Assessment , Psychiatric Status Rating Scales , Risk Factors , Somatoform Disorders/diagnosis , Somatoform Disorders/psychologyABSTRACT
Conversion disorder has been associated with hypnotic susceptibility for over a century and is currently still believed to be a form of autohypnosis. There is, however, little empirical evidence for the relation between hypnotic susceptibility and conversion symptoms. The authors compared 50 patients with conversion disorder with 50 matched control patients with an affective disorder on measures of hypnotic susceptibility, cognitive dissociation, and somatoform dissociation. Conversion patients were significantly more responsive to hypnotic suggestions than control patients. In addition, conversion patients showed a significant correlation between hypnotic susceptibility and the number of conversion complaints. These results provide the first evidence of a relationship between hypnotic susceptibility and the presence and number of conversion symptoms.