The anticholinergic burden is not associated with cognitive impairments in patients treated by electroconvulsive therapy for treatment-resistant depression

Abstract

Electroconvulsive therapy (ECT) is the most effective non-pharmacological treatment for treatment-resistant depression (TRD) but can expose to transient cognitive impairments. Understanding factors underlying these cognitive side effects is important. This study investigated the impact of anticholinergic treatments on cognitive performances after ECT courses for TRD in naturalistic condition. Impact of anticholinergic burden (Anticholinergic Impregnation Scale, AIS) on cognitive changes (Montreal Cognitive Assessment, MoCA) adjusted on depression level (Montgomery and Asberg Depression Scale, MADRS) was investigated in 42 patients who received an ECT course between 2017 and 2020 for unipolar or bipolar TRD. Collection of daily treatments given during ECT was carried out via the computerized traceability of treatments validated by nurses. Among the 31 treatments identified with an anticholinergic score, which represent only 38% of total treatments, the three most frequently given treatments were Lorazepam (47%), Venlafaxine (36%) and Cyamemazine (26%). Delayed recall was the most frequently impaired cognitive function after ECT courses. Using logistic regression, we found no association between the anticholinergic burden and the decrease in cognitive scores after ECT courses, adjusted on MADRS score evolution (p>0.1). Conversely, improvement in MADRS scores were correlated with improvement in attention MoCA subscores. This is a retrospective monocentric study with a moderate sample size using anticholinergic scales to calculate the anticholinergic burden without plasma dosage. Anticholinergic treatments did not seem to explain ECT-related cognitive impairments. This warrants further large prospective investigations including different measures of anticholinergic burden.