The authors tested working or recent memory in 24 stabilized
schizophrenic outpatients who were taking psychotropic medication. Memory
performance did not correlate with severity of schizophrenic symptoms,
verbal IQ, or serum neuroleptic levels, but there was a significant inverse
correlation between serum anticholinergic levels and performance on the
memory task. The results suggest that therapeutic doses of anticholinergics
may cause subtle impairments of cognitive functions.