Effect of Memantine on Positive Sign in Patients with Schizophrenia and Schizoaffective Disorders: A Randomized Double Blind Placebo Controlled Trial

Background and purpose: Memantine is a medication used to treat moderate to severe Alzheimer’s disease. Memantine targeting the glutamatergic system specifically N-Methyl-D-Aspartate offer a novel approach in treatment of psychiatric disorders such as schizophrenia and schizoaffective disorder. The purpose of this study was to evaluate the efficacy and safety of memantine in combination with antipsychotics in patients with schizophrenia and schizoaffective disorder. Materials and methods: A double-blind, placebo-controlled trial was performed in patients aged 18-65 years old with confirmed diagnosis of schizophrenia and schizoaffective disorder. Those who were pregnant, allergic to memantine, and not willing to participate in the study were excluded. Participants were assigned to receive either memantine (5-20 mg/day) (n= 29) or placebo (n= 29), in addition to antipsychotic for 90 days. The Positive and Negative Syndrome Scale (PANSS) was completed at baseline and day 30 and 90. Results: The study showed no significant difference in reduction of PANSS scores for positive sign between the treatment group (6.32±7.17) and controls (4.17±6.25) (P=0.07). Conclusion: Memantine was found to have no effect on positive sign of schizophrenia and schizoaffective disorder.   (Clinical Trials Registry Number: IRCT: 201310083210N5)