The effect of add-on memantine on positive, negative and depressive symptoms of schizophrenia: a double-blind, randomized, controlled trial

Abstract

Background. Although antipsychotics are the mainstay treatment of schizophrenia, they don't adequately address residual positive, negative and depressive symptoms. The aim of the present study is to assess the effect of adjunctive memantine treatment on positive, negative and depressive symptoms of schizophrenia. Methods. This randomized, placebo-controlled study was conducted in Noor Hospital, Isfahan, Iran, 2013-2014; 32 patients in maintenance treatment were included in each group, using block sampling; inclusion criteria were age 1865 years, normal intellectual ability, being diagnosed with schizophrenia for the past two years, being treated with fixed doses of atypical antipsychotic for at least three months before randomization. Exclusion criteria were pregnancy; breast feeding, having received electro-convulsive therapy in the past two weeks, drug or substance abuse and dependence, psychiatric/neurological comorbidities, and sensitivity to memantine. Patients in the intervention group were treated with memantine plus atypical antipsychotic; while in the control group, patients received placebo and atypical antipsychotic. Patients were assessed by Positive and Negative Symptom Scale (PANSS) and Calgary Depression Scale for Schizophrenia (CDSS) initially and every four weeks to the end of the 12th week. Data were analyzed in SPSS 17.0 using t-test, chi square, analysis of variance (ANOVA), and analysis of covariance (ANCOVA). Results. Positive symptoms (p=0.028), negative symptoms (0.004), general psychopathology (p<0.001), depressive symptoms (p<0.001) and total symptom severity (p<0.001) decreased significantly in patients receiving add-on memantine. Conclusion. This study shows that, add-on memantine would be helpful, in the adjunctive treatment of depressive, positive, negative and general symptoms in patients with schizophrenia.