Prevalence and Correlates of Cognitive Impairment in schizophrenia: A cross-sectional study from Southern Sri Lanka

Abstract Introductions: Cognitive impairment is a core feature of schizophrenia. This study assessed the prevalence of cognitive impairment, the degree of impairment in individual cognitive domains and sociodemographic and clinical correlates among patients with schizophrenia in southern Sri Lankan. Methods: A cross-sectional study was carried out at the psychiatry outpatient clinics of Teaching Hospital, Karapitiya, Sri Lanka. Their cognitive functions were assessed using the culturally validated Sinhala version of Addenbrooke’s Cognitive Examination – III (ACE-III-S). ACE-III-S score below 85.5 was considered as significant cognitive impairment. Linear and multiple regression analyses were used to assess the factors associated with cognitive impairment. A P value of 0.05 is considered significant. Results: One hundred forty patients with schizophrenia were assessed. Of this, 125 patients had significant cognitive impairment with a prevalence of 89.3% (95% CI:84.1-94.5). Impairment in each cognitive domain was as follows: 60% in attention, 65.7% in memory, 55% in fluency, 61.4% in language, and 63.6% in visuospatial skills. Impairment was not different between cognitive domains. A shorter duration of formal education (P = <0.001), longer duration of illness (P = <0.001) and higher dose of antipsychotics (P = 0.034) were independently associated with cognitive impairment. Conclusions: Nine out of ten patients with schizophrenia experienced significant cognitive impairment. Patients showed more than 50% impairment in all the cognitive domains. The cognitive domains did not show disproportionate impairment. This study highlights the importance of introducing routine cognitive assessment protocols and frequent reviews of antipsychotic medications.