Abstract
Work and social functioning in schizophrenia are strongly influenced by cognitive impairment so improving cognition is a priority in the treatment of schizophrenia. Until recently the lack of a widely accepted index of cognitive change for use in schizophrenia was a major obstacle to the development of cognition enhancing treatments. The MATRICS (measurement and treatment research to improve cognition in schizophrenia) consensus cognitive battery (MCCB) was developed as a standard cognitive battery for use in clinical trials of cognition enhancing treatments for schizophrenia and has attracted worldwide interest. To analyze the reliability and validity of a translated and adapted Polish approved academic version of the MCCB. Sixty one patients were assessed at baseline and again after 30 days. The study protocol approximated the MATRICS psychometric and standardization study; the 10 tests that comprise the MCCB were administered to participants. Functioning and psychopathological symptoms were also assessed. Patients and test administrators also assessed the tolerability and practicality of all the cognitive tests. All tests in the battery were found to have high test-retest reliability. All the tests were rated as tolerable and practical by patients and administrators. However practice effects were generally higher in the Polish version of the MCCB than in the original version. Our analysis corroborates previous evidence that the MCCB represents a good tool for assessing cognitive deficits in research studies of schizophrenia also in non-English speaking countries.