Effects of rivastigmine on cognitive function and quality of life in patients with schizophrenia.

We aimed to determine whether the cholinesterase inhibitor rivastigmine, an inhibitor of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), would improve quality of life and cognitive function in 16 clinically stable subjects affected by schizophrenia in the residual phase. Study subjects began rivastigmine treatment at a dose of 1.5 mg bid. This dose was escalated at monthly intervals in increments of 1.5 mg bid to a maximum of 6 mg bid. All subjects were followed for 12 months. Quality of life was assessed using the Satisfaction with Life Domains Scale (SLDS, a self-report scale containing 10 "satisfaction" items); cognitive function, attentional function, and aspects of learning and memory were evaluated using common neuropsychological tests. Psychopathology was evaluated by means of the Brief Psychiatric Rating Scale (BPRS). Rivastigmine treatment resulted in significant improvements in quality of life, which were paralleled by significant improvements in cognitive function, learning and memory, and trends for improvement in attention. The BPRS factor "anergia" showed significant improvement, while low baseline scores in other psychotic factors did not permit further improvements. There were no reports of nausea or vomiting. In conclusion, rivastigmine significantly improved quality of life in subjects with schizophrenia. These benefits may relate to the drug's effects on cognitive deficits and negative symptoms associated with the condition.