A double blind placebo controlled trial of donepezil adjunctive treatment to risperidone for the cognitive impairment of schizophrenia.

Background: Despite the beneficial effects of atypical antipsychotics on cognition, these improvements will not return most schizophrenic patients to normative standards of cognitive functioning. Therefore, other treatments need to be considered. Subtle changes in cholinergic function in schizophrenic patients provide the rationale to test the effectiveness of cholinesterase inhibitors in treating cognitive impairment in schizophrenia.