Executive functions and cognitive deficits in schizophrenia: comparisons between probands, parents and controls in India.

ABSTRACT

BACKGROUND: Cognitive impairment is said to be a core feature of schizophrenia. Executive function is an important cognitive domain. AIM: This study was undertaken to assess cognitive impairment among Indian patients with schizophrenia (Sz) or schizoaffective disorder (SzA), compared with their parents and unaffected individuals (controls). SETTINGS AND DESIGN: Executive functions as measured by Trail-making Test (TMT), of patients and their parents were compared with controls. The patients were recruited from the Outpatients' Department (OPD) of a government hospital. MATERIALS AND METHODS: Patients diagnosed as Sz or SzA (n=172) and their parents (n=196 families n=132, 119 fathers and 77 mothers) participated. We also included 120 persons with no history of psychiatric illness. Cognitive function was assessed with the TMT. The Information Score of the Post Graduate Institute Battery of Brain Dysfunction test, developed in India for Indian subjects was used as a proxy for general fixed knowledge. STATISTICAL ANALYSIS: Logistic and linear regression was used to compare cognitive deficits of cases, parents and controls. RESULTS: Cases and their parents took significantly more time than controls on Part B of the TMT. There were no statistically significant differences between cases and parents on any of the TMT parameters. Using regression analysis, the most significant correlates of all TMT parameters among cases were with occurrence of auditory hallucinations and current age. CONCLUSION: Cases, as well as their parents showed more cognitive impairment than controls on the TMT.