A randomized single-blind placebo controlled trial of Memantine, as addjunctive therapy for treatment of negative symptoms of paranoid schizophrenia

Abstract

This study analyzes the efficiency of memantine – an antagonist of N-methyl-D-aspartate receptors – as adjunctive therapy for the treatment of negative symptoms of paranoid schizophrenia. Fifty-two patients (30 males; age 20–50 years) were included with the diagnosis of F20.014 and F20.024 according to the international classification of diseases (version 10). The patients had been receiving neuroleptic monotherapy with a fixed dose for a period of at least 4 weeks prior to randomization. Clinical data were collected 8 weeks after memantine had been introduced as part of the treatment regimen. A patient was considered as responding to treatment if they a) scored 1-2 on the Clinical Global Impression Scale, and b) showed a greater than 25 % reduction of the total score on The Positive and Negative Syndrome Scale (PANSS) or a a greater than 20 % reduction on the negative subscale of PANSS. Forty-seven patients were randomized: treatment group (neuroleptic + memantine, n = 24, control group (neuroleptic + placebo, n = 23); 44 patients completed the study. Neither memantine nor placebo led to a reliable decrease of negative symptoms, and the groups did not differ from each other.