title: Influence of Antipsychotic and Anticholinergic Loads on Cognitive Functions in Patients with Schizophrenia.
abstract: Many patients with schizophrenia show cognitive impairment. There is evidence that, beyond a certain dose of antipsychotic medication, the antipsychotic daily dose (ADD) may impair cognitive performance. Parallel to their D2 receptor antagonism, many antipsychotics show a significant binding affinity to cholinergic muscarinic receptors. Pharmacological treatment with a high anticholinergic daily dose (CDD) significantly impairs attention and memory performance. To examine the relationships between individual cognitive performance and ADD and/or CDD, we conducted a retrospective record-based analysis of a sample of n = 104 in patients with a diagnosis of schizophrenia, all of whom had completed a comprehensive neuropsychological test battery. To calculate the individual ADD and CDD, the medication at the time of testing was converted according to equivalence models. After extracting five principal cognitive components, we examined the impact of ADD and CDD on cognitive performance in the medicated sample and subgroups using multiple regression analysis. Finally, locally weighted scatterplot smoothing (Loess) was applied to further explore the course of cognitive performance under increasing dosage. Results showed significant negative effects of ADD on performance in tests of information processing speed and verbal memory. No effects were found for CDD. The potential neuropsychopharmacological and clinical implications are discussed.
authors.affiliation: Department of Psychiatry, University of Heidelberg, 69115 Heidelberg, Germany; Psychiatrisches Zentrum Nordbaden, 69168 Wiesloch, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Rehse
authors.affiliation: Department of Psychiatry, University of Heidelberg, 69115 Heidelberg, Germany.
authors.forename: Marina
authors.initials: M
authors.lastname: Bartolovic
authors.affiliation: Department of Psychiatry and Psychotherapy, SRH Hospital Karlsbad-Langensteinbach, 76307 Karlsbad, Germany.
authors.forename: Katlehn
authors.initials: K
authors.lastname: Baum
authors.affiliation: Department of Psychiatry, University of Heidelberg, 69115 Heidelberg, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Richter
authors.affiliation: Department of Psychiatry, University of Heidelberg, 69115 Heidelberg, Germany; Department of Psychiatry and Psychotherapy, SRH Hospital Karlsbad-Langensteinbach, 76307 Karlsbad, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Weisbrod
authors.affiliation: Department of Psychiatry, University of Heidelberg, 69115 Heidelberg, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Roesch-Ely