Trial Description: A double-blind, placebo-controlled, prospective, randomized trial to evaluate the effects of two doses of amantadine or placebo in the management of antipsychotic-induced hyperprolactinemia and psychiatric status in patients with schizophrenia or schizoaffective disorder who are clinically stable on paliperidone ER or risperidone Consta. Placebo or amantadine 100 mg or 200 mg BID will be administered to participants for 4 consecutive weeks as an adjunctive therapy in 72 schizophrenia subjects treated with paliperidone or risperidone Consta to examine amantadine effects on fasting AM serum prolactin levels. Participants will be followed after suspension of amantadine or placebo for an additional 4 weeks for safety purposes. The goals of this study are to prospectively demonstrate that amantadine lowers prolactin levels, and evaluate the impact of amantadine on psychiatric symptoms, and on prolactin-related side effects in patients treated with paliperidone ER or risperidone Consta.
