Auditory hallucinations in schizophrenia: Intrusive thoughts and forgotten memories

Introduction. This paper presents a new cognitive model of auditory hallucinations in schizophrenia. We suggest that auditory hallucinations are auditory representations derived from the unintentional activation of memories and other irrelevant current mental associations. Our model proposes that a combination of deficits in intentional inhibition and contextual memory is critical to the experience of auditory hallucinations. The failure in intentional inhibition produces unwanted and uncontrollable mental events which are not recognised because they have lost the contextual cues that would normally facilitate recognition. Methods. This article amalgamates recently published data and presents a reanalysis of the findings on 43 patients with a diagnosis of schizophrenia (Badcock, Waters, Maybery, & Michie, 2005; Waters, Badcock, Maybery, & Michie, 2003a; Waters, Maybery, Badcock, & Michie, 2004a). Relative risk was also estimated to determine whether the combination of deficits increases the risk of having auditory hallucinations. Results. Almost 90% of patients currently experiencing auditory hallucinations showed the predicted combination of deficits on both inhibition and context memory, compared to only a third of patients without hallucinations. In addition, the results showed that those patients with the specified cognitive deficits were at an especially increased risk of having auditory hallucinations relative to patients without the deficits. Conclusions. The results of our investigations strongly support the role of intentional inhibition and context memory in auditory hallucinations. Critical consideration of the findings also suggests that additional cognitive processes might be important for the expression of this symptom.