Predictors of cognition in first episode psychosis

Cognitive deficits are common in the first episode of psychosis (FEP) and may begin much earlier. While some evidence suggests that the decline in cognition occurs over the untreated symptomatic period, including the prodromal phase, others point to these deficits being present even earlier. We aimed to investigate the differential effect of untreated symptomatic and pre-morbid phases on cognition in a large sample of FEP.

Two hundred and sixty eight FEP patients, admitted into a specialized early intervention service, were administered neuro-cognitive tests. The Circumstances of Onset and Relapse Schedule (CORS) was administered for measurement of duration of untreated psychosis (DUP), the duration of untreated illness (DUI) and demographic factors. The Pre-morbid Adjustment Scale (PAS) was used to measure different domains of pre-morbid adjustment. Seventy three healthy controls were also recruited for neuro-cognitive comparison.

We observed no effect of DUP and a minimal effect of DUI on cognitive functioning in FEP. Instead, the early educational pre-morbid adjustment domain was most strongly associated with cognition and predicted both global cognitive and verbal memory outcome in FEP.

Our results suggest that symptoms associated with the symptomatic phase of a FEP do not influence cognitive functioning in FEP. Instead, cognitive deficits in FEP may predate illness onset and may indicate susceptibility to such illness.