Anticholinergicity and cognitive processing in chronic schizophrenia

Patients with chronic schizophrenia suffer from alterations in cholinergic functioning due to several factors, including the disease diathesis and pha rmacologic treatments. Acetylcholine-cognition relationships are well explo red in normals but are unclear in schizophrenia. Prior work indicated serum anticholinergicity does not cause global cognitive impairment in this grou p (Tracy et al., 1998a), raising the possibility that anticholinergicity no rmalizes an abnormal hyperactive cholinergic state. Serum anticholinergic l evels were determined in 38 chronic schizophrenia patients using an establi shed radioreceptor assay method. Six cognitive functions associated with ch olinergic tone in normals were tested. The potential role of autonomic arou sal and cigarette smoking were also assessed as both have been linked to ch olinergic functioning. Regression analyses showed measures of inhibitory ex ecutive control and effortful memory accounted for a greater proportion of the Variance in the anticholinergicity measure compared to the other variab les. The data demonstrate a relationship between high anticholinergicity an d worse performance on two types of attention-resource demanding cognitive processes and do not support the notion that reduced cholinergic tone norma lizes a hyperactive cortical acetylcholine substrate. Relevant neuroanatomi c structures and implications for models of cognitive deficits in schizophr enia are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.