Innovations in the assessment of thought disorder.

Since the early descriptions of thought disorder in psychiatric patients were recorded by clini-cians such as Bleuler and Kraepelin, numerous studies have attempted to examine this phenomenon through the use of various techniques. Harvey (1983) suggests that three main methods have been used to assess thought disorder. Clinical investigations of deviant communication patterns and natural language studies have both examined the verbal communication of individuals believed to possess thought disorder. Similarly, laboratory studies have examined cognitive deficits in these same individuals in the hope of discovering the processes that underlie deviant speech. In reviewing the present state of research on thought, it becomes immediately apparent that the vast majority of research in this area has focused on speech as a direct reflection of thought. A possible explanation for this emphasis has been postulated by Schwartz (1978), who suggests that since most patients are capable of verbal communication, this stable form of behavior may be easily obtained as an index of psycho-pathology among subjects. While deviant speech patterns have been used extensively as a tool for assessing disordered thought, agreement about the definition of thought disorder and its assessment techniques has eluded researchers thus far (Andreasen and Grove 1986). In light of this inconsistency, it has been our aim over the past several months to study thought disorder from an entirely different perspective. We are currently developing a self-report questionnaire designed to assess thought disorder in psychiatric patients. Unlike previous questionnaires of its kind, this particular inventory focuses directly on the thoughts of the patient instead of relying on speech as a potential index of thought. Since previous research has indicated that psychiatric patients can'give subjective reports of their illness (Beaber et al. 1985; Davidhizer 1985; Phillipson and Harris 1985), it was our belief that such reports would provide a more accurate and efficient means of diagnosing and predicting outcome in patients with thought disorder. Fifteen subscales composed of 304 items were generated by clinicians and researchers based on interviews with psychiatric patients. Thus far, following the method outlined in Jackson's Sequential System for Personality Scale Development (Jackson 1970), statistical analyses performed on the responses of 100 inpatient and normal subjects have yielded reliability coefficients for the subscales ranging from 0.8141 to 0.9412. In a preliminary analysis on a small sample of subjects, it was also discovered that schizophrenic subjects scored significantly higher than normal subjects on 13 of the 15 …