Symptoms versus neurocognitive skills as correlates of everyday functioning in severe mental illness.

A critical review of cross-sectional and longitudinal studies conducted from 2001-2005 investigating the relationship of symptoms and neurocognitive skills to everyday functioning in patients with severe mental illness was completed. Literature and bibliographic searches identified seven studies, which were grouped according to the methodology of measurement of everyday function selected: clinician-rated scales of psychosocial function based on patient and proxy report; performance-based measures of functional capacity; or competitive vocational success. Results of the review revealed that negative symptoms, such as social withdrawal, psychomotor slowing and blunted affect, and neurocognitive measures of attention, executive function, working memory, verbal memory and psychomotor speed, were most commonly linked to all three domains of everyday function. With the exception of one study, there was no evidence of a relationship between positive symptoms, such as delusions and hallucinations, and everyday function. The implications of these findings for guiding future research are discussed.