The effect of anticholinergic burden on cognitive and daily living functions in patients with schizophrenia

This study aimed to explore the association between medication-associated anticholinergic burden and cognitive and daily living functions in patients with schizophrenia.

Sixty patients with schizophrenia were recruited. We used the Anticholinergic Drug Scale (ADS) for evaluating medication-associated anticholinergic burden. The MATRICS Consensus Cognitive Battery (MCCB) and the University of California San Diego Performance-based Skills Assessment (UPSA) were used for evaluating cognitive and daily living functions. To assess clinical symptoms, psychiatrists conducted interviews using the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia.

Subjects were divided into low (n = 31) and high (n = 29) anticholinergic burden based on ADS scores of 3 or more. The "high ADS" group had poorer cognitive (composite MCCB score, p < 0.001) and daily living functions (total UPSA score, p = 0.001) than the "low ADS" group. Medication-associated anticholinergic burden was negatively correlated with cognitive functions (composite MCCB score, r = -0.512, p < 0.001) and daily living functions (total UPSA score, r = -0.355, p = 0.005). A regression analysis showed that anticholinergic burden significantly explained the decline in cognitive functions (composite MCCB score, R² = 0.262, p < 0.001) and daily living functions (total UPSA score, R² = 0.126, p = 0.005). Explanatory power was reduced after a covariate adjustment, but the effects of the composite MCCB score (p = 0.013) and of the transportation domain score of the UPSA (p = 0.048) remained significant.

Our analysis shows that anticholinergic burden reduces cognitive and daily living functions in patients with schizophrenia. A drug strategy with minimal anticholinergic burden may be helpful to patients if it does not adversely affect clinical symptoms.