Neurocognitive function and outcome in first-episode schizophrenia: a 10-year follow-up of an epidemiological cohort

The natural history of neurocognitive impairments in schizophrenia is unclear. We aimed to characterise this in an epidemiological first-episode cohort and relate it to long-term outcome. All but I of 112 first-episode psychosis cases ascertained from a geographical catchment area were traced at 10-12 years. Neurocognitive and multi-dimensional outcome assessments were made at interview in 49 cases with schizophrenia and related disorders. Twenty-four of these had completed the same neurocognitive battery at index admission. Comparisons with normative data showed impaired executive function in a proportion of the first episode (FE) sample at baseline. Significant deterioration was seen over the follow-up period in three of nine sub-tests: object assembly, picture completion and memory for designs. Neurocognitive impairments at outcome, but not baseline, correlated with clinical outcome. Poor outcome was associated with a decline in performance on visuo-spatial tasks and a failure to improve on frontal-temporal tasks during the follow-up period. Executive deficits may be present in the FE, but do not progress over 10-12 years. Visuo-spatial function is spared in the FE but may deteriorate over time. Changes in both these patterned deficits are predictive of clinical outcome. (C) 2003 Elsevier Science B.V. All rights reserved.