Schizophrenia is a life-long brain disorder affecting approximately 1 percent of Americans each year. Schizophrenia can be extremely disabling, causing people to hear voices, experience paranoia or hallucinations, believe that others are controlling their thoughts, and even fail at maintaining a job or caring for themselves. Current medications help to relieve most of these negative symptoms, but not all. Many people with schizophrenia still suffer from low energy levels, an inability to concentrate, and memory loss. Galantamine is a medication that is used to improve memory and energy levels in people with Alzheimer's disease, and CDP-choline is a nutritional supplement. The purpose of this study is to evaluate the effectiveness of adding galantamine and CDP-choline to a stable anti-psychotic medication regimen of risperidone as a way of improving symptoms in adults with schizophrenia.