OBJECTIVE: It has been well established that schizophrenic patients have
neurocognitive deficits, but it is not known how these deficits influence
the daily lives of patients. The goal of this review was to determine
which, if any, neurocognitive deficits restrict the functioning of
schizophrenic patients in the outside world. METHOD: The author reviewed
studies that have evaluated neurocognitive measures as predictors and
correlates of functional outcome for schizophrenic patients. The review
included 1) studies that have prospectively evaluated specific aspects of
neurocognition and community (e.g., social and vocational) functioning (six
studies), 2) all known studies of neurocognitive correlates of social
problem solving (five studies), and 3) all known studies of neurocognitive
correlates and predictors of psychosocial skill acquisition (six studies).
RESULTS: Despite wide variation among studies in the selection of
neurocognitive measures, some consistencies emerged. The most consistent
finding was that verbal memory was associated with all types of functional
outcome. Vigilance was related to social problem solving and skill
acquisition. Card sorting predicted community functioning but not social
problem solving. Negative symptoms were associated with social problem
solving but not skill acquisition. Notably, psychotic symptoms were not
significantly associated with outcome measures in any of the studies
reviewed. CONCLUSIONS: Verbal memory and vigilance appear to be necessary
for adequate functional outcome. Deficiencies in these areas may prevent
patients from attaining optimal adaptation and hence act as "neurocognitive
rate-limiting factors." On the basis of this review of the literature, a
series of hypotheses are offered for follow-up studies.
Abstract Teaser