Correlates of cognitive impairment in first episode schizophrenia: the EUFEST study.

Background: Profile and correlates of cognitive deficits in first episode (FE) schizophrenia patients are still debated. The present study is aimed to clarify in a large sample of FE patients the extent of impairment in key cognitive domains and its relationships with demographic and clinical variables.

Method: The European First Episode Schizophrenia Trial collected demographic, clinical and neurocognitive baseline data in 498 FE patients with minimal or no prior exposure to antipsychotics. Two-hundred-twenty healthy subjects (HS) were also evaluated. Neurocognitive assessment included the Rey Auditory Verbal Learning Test; Trail Making A and B, Purdue Pegboard and Digit-Symbol Coding.

Results: Patients performed worse than HS on all tests (effect sizes from -0.88 to -1.73). Correlations with psychopathological dimensions were weak and involved reality distortion and disorganization. The duration of untreated psychosis (DUP) was not associated with cognitive impairment. Subjects living alone had a better neurocognitive performance, while the occupation status did not reveal any association with cognition.

Conclusions: A moderate/severe impairment of processing speed, motor dexterity, verbal memory and cognitive flexibility was found in the largest sample of FE patients analyzed so far. The impairment was largely independent from psychopathology and not associated with DUP.