title: Correlates of perceptual distortions in clinical and non-clinical populations using the Cardiff Anomalous Perceptions Scale (CAPS): associations with anxiety and depression and a re-validation using a representative population sample.
abstract: Although the literature on hallucinations in psychiatric patients shows clear links with anxiety and depression, associations of affect with a wider array of anomalous perceptual experiences have been much less studied. This study investigated patients with psychosis (N=29) and a non-clinical population (N=193) using the Cardiff Anomalous Perceptions Scale (CAPS), a measure of perceptual distortion and associated distress, intrusiveness and frequency; along with measures of depression, anxiety and worry. The study also allowed a re-validation of the CAPS in a more representative sample of the UK population. Moderate, reliable correlations with depression, anxiety and worry were found in the non-clinical population with the association being stronger in psychotic patients. The study re-confirmed that anomalous perceptual experiences are common in the general population and that a significant minority (11.9%) have higher levels than the mean of psychotic patients. Scale reliability and validity were also re-confirmed, and the CAPS score was found to be unrelated to age or gender in either sample. As in the original study, factor analysis produced a three-factor solution, although factor theme was not fully replicated: as before, a cluster of first-rank symptoms emerged, but with equivocal evidence for a temporal lobe factor and no replication of a 'chemosensation' component.
authors.affiliation: Institute of Psychiatry, King's College London, UK. HalliganPW@cf.ac.uk
authors.forename: Vaughan
authors.initials: V
authors.lastname: Bell
authors.forename: Peter W
authors.initials: PW
authors.lastname: Halligan
authors.forename: Katherine
authors.initials: K
authors.lastname: Pugh
authors.forename: Daniel
authors.initials: D
authors.lastname: Freeman
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001007:Anxiety / Q000175:diagnosis* / Q000503:physiopathology*; D003863:Depression / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010469:Perceptual Distortion / Q000502:physiology*; D011594:Psychometrics; D015203:Reproducibility of Results; D012727:Sex Characteristics; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D055815:Young Adult