On keeping (intrusive) thoughts to one's self: testing a cognitive model of auditory hallucinations

Previous studies have linked intrusive cognitions (hallucinations and obsessions) with inhibitory dysregulation. Combined deficits in intentional inhibition and context memory have been proposed to explain the intrusive nature and perceived nonself origin of auditory hallucinations (Waters et al., 2006). This study tested the prediction, from this model, that individuals with obsessive-compulsive disorder (OCD), who do not mistake the origin of their intrusive thoughts, will show a deficit of intentional inhibition but intact contextual memory.

The performance of 14 individuals with OCD and 24 healthy controls was compared on two measures of intentional cognitive inhibition and on a context memory task.Results. Participants with OCD were significantly impaired on both measures of inhibition but were not significantly different from controls in any condition of the context memory task.

The predictions were confirmed. Individuals with OCD, like schizophrenia patients with auditory hallucinations, showed impaired intentional inhibition. This impairment might be responsible for the intrusive thoughts reported in both disorders, and might also partially account for the high rates of comorbidity of OCD and schizophrenia. Finally, intact context memory abilities in OCD may contribute to an efficient memory system, and may differentiate this group from those with hallucinations.