The stability of ideas--measuring changes in delusions in a state hospital

Barbara A. Belcher-Timme (1989)

Research on delusions has been difficult to assimilate into mainstream psychology. In part this is because delusions have traditionally been viewed as unitary, discrete entities occurring in severe psychopathology. This paper follows Strauss' (1969) idea that delusions ought to be placed, instead, on a continuum. In contrast to the idea of a unitary, discrete entity, such a continuum conceptualization allows for a good deal more flexibility in the understanding of the phenomenon of delusions and establishes a more complete frame within which to conduct meaningful research. This continuum reflects the underlying processes found in general idea formation, as reflected in that literature. Traditionally delusions have been seen as fixed or unchanging. In contrast to this traditional position, the general thesis of this paper is that delusions and normal essential ideas are formed and maintained according to the same underlying mental processes. Therefore delusions ought not to be more or less durable than other ideas, and what we know about each should inform the other. This research measured change in delusions over time in a state hospital. Kendler, Glazer, and Morgenstern's (1983) seven point Likert scale, measuring the dimensions of bizarreness, extension, disorganization, pressure, and conviction, was used with 21 schizophrenics. Results revealed poor interrater reliability and showed unexpectedly significant changes across all dimensions which suggested dramatic change. Rather than assuming that ideas and delusions are in fact different phenomena, these results call into question the method of measuring changes in delusions used in this research. A modification of the scale, for use in this setting, from administration using interviews to record review was implicated in the unexpected results. The qualitative analysis of the data supported the hypothesis that typically there are more subtle changes by degree in the underlying processes of delusions while there is basic stability in the content core. It is argued that through a constriction of available imagery and schema, and via a self confirmatory bias, delusional subjects selectively attend to and even distort their context to make durable attributions. It is speculated that the same process is evident in nondelusional patients.