Prospective memory in schizophrenia: primary or secondary impairment?

Although a number of studies have now shown that schizophrenia is associated with impaired memory for future intentions (prospective memory), the degree and nature of the impairment remains to be clarified, as does the degree to which this impairment is secondary to deficits in other aspects of cognition. In the present study thirty participants with schizophrenia were compared with demographically matched controls on Virtual Week, a measure that closely represents the types of prospective memory tasks that actually occur in everyday life, and provides an opportunity to investigate the different sorts of prospective memory failures that occur. Participants with schizophrenia were significantly and comparably impaired on Virtual Week, irrespective of the specific prospective memory task demands. Importantly, after controlling for general cognitive functioning, executive functioning and retrospective memory, although the absolute magnitude of the deficit was reduced, significant impairment remained. These results suggest that individuals with schizophrenia experience generalized difficulties with prospective memory, and that whilst other cognitive deficits contribute to these difficulties, there is something unique to prospective remembering that is additionally disrupted in schizophrenia.