Impact of Anticholinergic Burden on Cognitive Functions in Individuals With Bipolar Disorder, Schizoaffective Disorder, and Schizophrenia

Abstract

Objective: Bipolar disorder (BD), schizoaffective disorder (SAD), and schizophrenia (SCH) are psychiatric disorders characterized by persistent cognitive impairments, even during periods of remission. Psychotropic medications commonly used to manage these conditions have anticholinergic properties, which may contribute to cognitive impairment. Methods: This study examined the relationship between anticholinergic medication burden and cognitive function in individuals diagnosed with BD, SAD, and SCH. Anticholinergic burden was assessed using two validated scales, the Anticholinergic Cognitive Burden Scale (ACB) and the CRIDECO Anticholinergic Load Scale (CALS). Cognitive function was evaluated using the Digit Span and the Öktem Verbal Memory Process Test. Retrospective data analysis was conducted to examine the association between anticholinergic medication burden and cognitive performance. Results: The study included 132 participants including individuals with BD (n = 45), SAD (n = 29), and SCH (n = 58). Higher scores on the ACB and CALS scales were associated with impairments in working memory and immediate memory in the BD group. Similarly, increased anticholinergic burden was associated with immediate memory deficits in the SCH group. However, no significant association was found in the SAD group despite a higher anticholinergic burden. Conclusion: Our findings highlight the impact of anticholinergic burden on neurocognitive function in individuals with severe psychiatric disorders. The association between anticholinergic burden and cognitive impairment extends beyond SCH spectrum disorders to include BD. These findings underscore the importance of considering anticholinergic burden in psychiatric treatment strategies and call for further research with larger samples to better understand cognitive consequences and refine prescribing practices. Copyrightⓒ 2025, Korean College of Neuropsychopharmacology.