Prevalence and correlates of cognitive impairment in schizophrenia: a cross-sectional study from a teaching hospital southern Sri Lanka.

Introductions: This study assessed the prevalence of cognitive impairment, the degree of impairment in individual cognitive domains and sociodemographic and clinical correlates among patients attending to psychiatry clinics at Teaching Hospital, Karapitiya, Sri Lanka.

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 regression analysis was 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. Advancing age (P < 0.001), shorter duration of formal education (P = < 0.001), longer duration of illness (P = < 0.001) and not having a full-time employment (P = 0.020) showed a positive association with cognitive impairment.

Conclusions: Nine out of ten patients with schizophrenia experienced significant cognitive impairment. Patients showed more than 50% impairment in all cognitive domains. The cognitive domains did not show disproportionate impairment. This study highlights the importance of introducing routine cognitive assessment protocols in patients with schizophrenia.