Factorial structure of the hallucinatory experience: continuity of experience in psychotic and normal individuals

Examination of the distribution of the hallucinatory experience may aide in the determination of their continuity and the psychological mechanisms that mediate their occurrence. Past investigators have found that hallucinatory experiences are not limited to disordered individuals and can be induced in the laboratory and occur naturally in the general population. Few reports to date, however, have directly investigated the continuity of the experience by comparing hallucinatory behavior of psychotic patients with a nonclinical sample. In the present study, we examined the architecture of the hallucinatory experience by comparing the factorial structure of the Launay-Slade Hallucination Scale using psychotic patients with active hallucinations, psychotic inpatients without hallucinations, and a group of university students. In support of the continuum model of psychosis, a very similar factor-analytic solution was obtained for all three groups. Discriminant function analysis, however, revealed that all groups achieved a high classified rate by their item responses. These results are consistent with the notion that expression of hallucinatory behavior exists along a continuum, but at a certain level of symptom severity beyond a critical threshold, the behavior becomes discontinuous and dysfunctional.