Positive psychosis symptom structure in the general population: Assessing dimensional consistency and continuity from “pathology” to “normality”

Abstract

The current study assessed the dimensionality of positive psychosis symptoms. Data from the National Comorbidity Survey (1990–1992) was used to examine the underlying factor structure of positive psychosis symptoms based on participants’ responses to the 13 Composite International Diagnostic Interview (CIDI) psychosis screening items. Confirmatory factor analysis (CFA) was used to compare four theoretically based competing factor analytic models of positive psychosis. Fit statistics indicated that the best fitting model was comprised of three correlated factors: a hallucinations factor, a Schneiderian delusions factor, and a paranoid delusions factor. There were no significant differences between the sexes on scores for the Schneiderian Delusions and Paranoid dimensions; however, females scored significantly higher on the Hallucinations dimension. At an item level, male respondents were significantly more likely to report experiences of paranoia; being controlled by an external force; and having their thoughts stolen by another. Females, on the other hand, were significantly more likely to experience auditory, olfactory, and tactile hallucinations. They were also more likely to believe that others were reading their mind. The three underlying factors were consistent with existing clinical models of positive psychosis symptom dimensionality and provide further evidence of a continuum of psychosis.

Keywords:

• psychosis
• continuum
• confirmatory factor analysis
• hallucinations
• delusions