Anticholinergic burden and its relationship with cognitive impairment in a neuropsychiatric unit

The use of drugs with anticholinergic activity is widespread and appears to be associated with an increased risk of cognitive impairment. We evaluated the prevalence of anticholinergic prescriptions in a neuropsychiatric unit, the anticholinergic burden and its relationship with cognitive impairment.

A cross-sectional observational study was conducted with 135 patients. Sociodemographic data, substance use, medical and psychiatric diagnoses, presence of cognitive impairment, and Mini-Mental State Examination (MMSE) score were collected. Anticholinergic burden was assessed using the Anticholinergic Cognitive Burden Scale (ACB) and a composite index of 14 scales, considering a high anticholinergic burden ≥3 points. Descriptive analysis, the chi-squared test, Student's t-test, Pearson's correlation coefficient, and multiple lineal regression models adjusted for confounding factors were performed, with p < 0.05 for statistical significance.

The mean number of anticholinergics per patient was 4.1 ± 1.7. According to the ACB, the mean burden was 4.8 ± 2.5. The burden was higher in patients with cognitive impairment (t = -2.38; p = 0.019). Among those exposed to high burden, 71.7% presented impairment vs. 51.7% exposed to low-moderate burden (χ² = 4.13; p = 0.042; OR = 2.36). With the 14-scale composite, the mean burden was 5.9 ± 2.8. A higher prevalence of impairment was observed in high burden (70% vs 46.7%), although this was not significant (χ² = 3.30; p = 0.069; OR = 2.36). The correlation between ACB burden and MMSE was negative and significant (r = -0.178; p = 0.039), whereas with the composite index, the correlation between total burden and MMSE was not significant (r = -0.092; p = 0.289). ACB burden was also associated with a lower MMSE score in the model adjusted for sex and age (B = -0.27; p = 0.047), losing significance after controlling for education and comorbidities (B = -0.24; p = 0.072). The anticholinergic burden estimated with multiple scales showed non-significant coefficients.

High anticholinergic consumption and burden are observed in patients with neuropsychiatric disorders, especially those with cognitive impairment. A negative correlation was detected between scores on the ACB scale and the MMSE. The findings confirm that, despite the known negative effect of anticholinergics on cognition, their prescription remains very high in populations at high risk of cognitive impairment.