Background. Cognitive models suggest that auditory hallucinations are experienced when mental events are misattributed to an external source; therefore, this study was designed to examine attributional biases in patients experiencing auditory hallucinations. The study also examined the role of metacognitive beliefs in the experience of auditory hallucinations, as some theories have implicated metacognition in the development and maintenance of auditory hallucinations.

Methods. Fifteen participants with a diagnosis of schizophrenia experiencing auditory hallucinations were compared with 15 non-hallucinating schizophrenics and 15 non-psychiatric control subjects on several measures, including an immediate source monitoring task and a questionnaire assessing metacognitive beliefs.

Results. Results indicated that patients experiencing hallucinations exhibited the predicted bias towards misattributing internal events to an external source, as measured by ratings of internality of responses in a word association task. All groups had lower perceived levels of internality and control for emotionally salient words, which provides further evidence for the importance of emotional content in hallucinations. Patients experiencing hallucinations were found to score higher than the other two groups on metacognitive beliefs about uncontrollability and danger and positive beliefs about worry. In addition, a logistic regression analysis showed that beliefs about uncontrollability and danger were predictive of whether subjects experienced auditory hallucinations or not.

Conclusions. These results offer considerable support to cognitive bias models of auditory hallucinations, particularly those that implicate metacognition.