Validation studies of the Paranoia Checklist (Portuguese version) in mixed sample of patients and healthy controls

Introduction

Paranoid ideation has been consistently found as a phenomenon presented across the population continuum, and a theme that most people find in their everyday thoughts.

Objective

To validate and study the psychometric properties of the Paranoia Checklist in a mixed (clinical and non-clinical) sample, in an extension of the study by Freeman et al. (2005).

Method

Self-report questionnaire were completed by 392 individuals, with the aid of a psychologist when necessary.

Results

The PC has shown to be a measure capable of distinguishing between clinical and non-clinical group of participants regarding the two dimensions of paranoid thoughts: frequency and conviction. Scores fitted an exponential curve, similar to the initial studies with the original version of the checklist.

Conclusion

The assessment of paranoia has shown to be a continuum process common to clinical and non-clinical groups. The PC is a psychometrically sound measure to assess different paranoid thoughts on a multidimensional perspective and with sensitivity to distinguish groups of patients and healthy individuals, being suitable for use both in clinical and research settings.