Memantine as an Adjuvant in Cognitive Symptoms of Schizophrenia with a Chronic Course: A Follow-up Study

Schizophrenia is a multifaceted and heterogeneous psychiatric disorder, marked by the presence of positive, negative, and cognitive symptom domains. In the chronic course, few symptoms remain persistent, leading to socio-occupational impairment. Few studies have used memantine (an NMDA receptor antagonist) as an adjunctive treatment, noting reductions in both positive and negative symptoms, accompanied by improvements in cognitive performance and overall functioning. The present study explored the effectiveness of adding memantine for cognitive symptoms in schizophrenia with a chronic course.

This prospective, single-arm, open-label study used a pre-post design. A total of 30 individuals with schizophrenia, diagnosed based on ICD-10 criteria and having an illness duration of more than two years, were included. Socio-demographic data were collected, and the Addenbrooke's Cognitive Examination Scale-Revised (ACE-R) was administered at baseline. Subsequently, memantine was added to their ongoing treatment regimen. The ACE-R assessment was repeated after eight weeks. Data was analyzed using R software version 4.4.1.

Different ACE-R score variables were compared before and after adding memantine. A significant relationship was found between ACE-R scores after adding memantine and the baseline scores (p < .001), except for the writing subcomponent of the language variable.

The results of this study suggest that adding memantine to an antipsychotic treatment regimen may provide beneficial effects on cognitive symptoms in chronic schizophrenia, with good tolerability and minimal adverse effects.

The study was registered under the Clinical Trials Registry in India (CTRI), CTRI/2024/12/077774.