Dissociative and metacognitive factors in hallucination-proneness when controlling for comorbid symptoms.

INTRODUCTION: Recent studies have linked hallucination-proneness to dysfunctional metacognitive beliefs, dissociation, and disrupted capacity to discriminate between internal and external cognitive events (reality discrimination). This study addressed a number of methodological limitations of previous research by investigating the relationship between hallucination-proneness and the aforementioned variables while controlling for comorbid symptoms. METHOD: A large sample of nonclinical participants was screened on measures of hallucination-proneness, cognitive intrusions, paranoid ideation, metacognitive beliefs, and dispositional mindfulness (including measures of dissociation-like experiences). In addition, a signal detection task was used to investigate reality discrimination in four subgroups of participants selected on the basis of their scores on hallucination-proneness and intrusions. RESULTS: Regression analyses for the self-report data were conducted to investigate the predictors of hallucination-proneness and paranoia when controlling for comorbid symptoms. Also, between-group differences on the behavioural data were tested to determine whether perturbed reality discrimination is specifically associated with hallucination-proneness rather than cognitive intrusions. Results revealed that metacognitive beliefs are more strongly associated with intrusions and paranoia than hallucination-proneness, whereas hallucination-proneness is related to perturbed reality discrimination and dissociation. CONCLUSIONS: These results clarify previous research on metacognitive dysfunction in hallucination-proneness, and highlight the importance of controlling for the covariation among symptoms when investigating the cognitive processes underlying psychotic experiences.