Donepezil in schizophrenia - is it helpful? An experimental design case study

Objective: To assess the clinical and cognitive effects of adding donepezil, a reversible acetylcholinesterase inhibitor, to the risperidone treatment of a high functioning stable out-patient with schizophrenia. Method: Case study using an experimental ABAB design. Assessments were completed objectively by standardized neuropsychological tests and clinical rating scales and subjectively with visual analogue scales. Results: Strong improvements attributable to donepezil were found for verbal fluency and the patient's subjective response. No adverse changes were noted in psychiatric symptoms or side effects. Conclusion: Cholinergic enhancement as an adjunctive treatment in schizophrenia should be explored in larger controlled trials.