Association of anticholinergic load with impairment of complex attention and memory in schizophrenia.

Objective: The authors' goals were 1) to establish a clinically useful standard index of the relative anticholinergic potency of psychiatric medications; 2) to determine which cognitive functions are most affected by the administration of anticholinergic medications to patients with schizophrenia; and 3) to compare in vitro and clinically derived indexes of anticholinergic load in predicting these cognitive impairments.

Method: One hundred six clinically stable patients with schizophrenia were given a brief neuropsychological battery and evaluated on a standard symptom rating scale. The anticholinergic load associated with their psychiatric medications was estimated by using 1) a pharmacological index, calculated from a compilation of published studies reporting in vitro brain muscarinic receptor antagonism, and 2) a clinical index, based on clinician ratings of the anticholinergic side effects of medications.