Measuring stability of cognitive impairment in inpatients with schizophrenia with alternate forms of the Montreal Cognitive Assessment during acute hospitalization.

Cognitive impairment is a core feature of schizophrenia. Measuring the stability of cognitive impairment is important for further understanding of this disorder. The Montreal Cognitive Assessment (MoCA) has been demonstrated to be a brief and effective screening tool in detecting cognitive impairment in patients with schizophrenia. It has alternative versions designed for longitudinal settings. The current study retrospectively analyzed the total and subscores of two versions of the MoCA, administered to a group of inpatients with severe schizophrenia at admission and discharge, to measure their cognitive stability during hospitalization. The results revealed that the test-retest reliability coefficient of the MoCA had good reliability, suggesting the two alternative versions of the MoCA are reliable measurements for assessing cognitive impairment repeatedly in patients with schizophrenia. The paired-samples t-test showed that the overall cognitive impairment of patients measured by two forms of the MoCA remained stable during acute hospital stay and across symptom changes. Furthermore, the results showed that patients' cognitive stability was not related to their symptom/illness severity improvement, age, education, or length of stay.