Spatial working memory deficits and clinical symptoms in schizophrenia: a 4-month follow-up study.

BACKGROUND: Our goal was to examine spatial working memory function in relation to clinical symptoms of schizophrenia over a period of 4 months. METHODS: We assessed spatial working memory, spatial detection and clinical symptoms in 34 acutely psychotic schizophrenia patients within the first 2 weeks of hospitalization, and 4 months later. Spatial working memory was assessed by a delayed response task. A spatial control task was included to rule out simple sensorimotor deficits. Positive and negative symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). Thirty-nine matched normal control subjects were also examined on the same tasks over the same period. RESULTS: Patients showed deficits in working memory, but they performed well on the spatial control task. Both positive and negative symptoms improved at the 4-month follow up. Spatial working memory also improved over time but there was still a significant deficit at the follow-up session. CONCLUSIONS: These results indicate that both symptoms and spatial working memory improved 4 months after the initial hospitalization but spatial working memory, hypothesized to be mediated by the dorsolateral prefrontal system, did not normalize. Thus, spatial working memory deficit may be a stable marker for schizophrenia.