Cognitive dysfunction and real world disabilityin clinically stable patients with bipolar disorderand schizophrenia: a cross sectional study fromIndia

Introduction : Cognitive deficits in various domains have been shown in patients with schizophrenia and bipolar disorder in the western population. The purpose of the present study was to compare the neurocognitive function in a cohort of Indian patients with that of normal controls. Methods: Performance on tests of attention, visual and verbal memory in 25 patients with schizophrenia in remission and 25 euthymic bipolar disorder patients was compared to 25 normal controls. Correlation analysis was used to look for relationship between illness factors, cognitive function and disability. We also correlated the effect sizes of cognitive deficits in the patient groups. Results: Both patient groups performed significantly worse than normal controls on most cognitive tests. The resulting effect sizes ranged from 0.37 to 0.98 (mean = 0.83) across tests for schizophrenia patients and from 0.08 to 0.85 (mean = 0.63) for bipolar disorder patients. There was a correlation between memory dysfunction and functional disability. Discussion: Patients with bipolar disorder displayed cognitive deficits that were milder but qualitatively similar to those of patients with schizophrenia. This finding is similar to studies done in the western population. The cognitive deficits were significantly associated with real-world functional disability. However, employment rates remained high in the patient population suggesting that factors such as family support reduce disability due to major mental illnesses in developing countries like India.M