Measuring memory impairment in community-based patients with schizophrenia. Case-control study

Abstract

Background: The majority of memory impairment studies in schizophrenia are cohort studies using laboratory-based tests, which make it difficult to estimate the true extent and relevance of memory impairment in patients with schizophrenia in the community.

Aims: To examine the extent of memory impairment in community-based patients with schizophrenia using a clinically relevant test.

Method: All patients with schizophrenia (n=190) in one catchment area were identified, of whom 133 were potentially eligible for the study; 73 patients volunteered to take part. They were assessed using the Rivermead Behavioural Memory Test (RBMT), the National Adult Reading Test, the Positive and Negative Syndrome Scale, the Health of the Nation Outcome Scales and the Scales and the Office for National Statistics Classification of Occupation. Their performance on the memory test was compared with that of matched controls (n=71).

Results: Patients as a group performed significantly worse (P<0.001) than controls on the RBMT. Using the RBMT normative scores, 81% of patients were found to have impaired memory compared with 28% of controls.

Conclusions: Using a clinically relevant test, the majority of community-based patients with schizophrenia may have memory impairment.