[Polish version of the Revised Hallucination Scale (RHS) by Morrison et al. Its factor analysis and the prevalence of hallucinatory-like experiences among healthy participants].

AIM

The study aimed at presenting the Polish version of Morrison's et al. (2002) Revised Hallucinations Scale (RHS). Factor structure of the RHS was of interests. Moreover, we were interested in the incidence of hallucinatory-like experiences among healthy subjects.

METHOD

Polish version of RHS was elaborated following the back-translation procedure. Then, it was administered to 213 healthy persons. Factor structure analysis of RHS was conducted. Finally, based on the RHS scores, frequency of selected visual and auditory hallucinatory like experiences were calculated.

RESULTS

Factor analysis of RHS revealed four factors structure: 1) imagery vividness; 2) auditory and visual perceptual anomalies; 3) experience of dissociation; 4) auditory hallucinatory like experiences. Four factors explained 51.54% of total variance in the RHS. The scale has good reliability (Cronbach's alpha varied from 0.7 to 0.88). Frequency of selected auditory hallucinatory like experiences varies from several to a dozen percent. Similar results were revealed for visual hallucinatory like experiences. These experiences that are similar to hallucinations observed among psychotic patients were observed seldom.

CONCLUSIONS

The factor structure of Polish versions of the RHS is comparable to the original one. However, we have found a new subscale that may represent the experience of dissociation. The Polish version of the RHS is characterised by good psychometric properties and may be used as an assessing scale for psychotic like experiences in a population. Our results suggest that hallucinatory like experiences are present among healthy subjects and those phenomenon may represent a psychosis phenotype.