Background: Memantine is a non-competitive N-methyl-d-aspartate receptor antagonist currently used for the treatment of Alzheimer's disease as an approved indication. However, as knowledge of signaling pathways is increasing, the therapeutic potential of memantine is being applied for the treatment of various psychiatric illnesses.
Methods: The PubMed online database was searched for the use of memantine in various psychiatric disorders. Case studies, open-label trials, and controlled trials from the search were included.
Results: Memantine monotherapy was found to exert efficacy in several neuropsychiatric conditions, including autism spectrum disorder, binge eating disorder, and attention-deficit/hyperactivity disorder. For posttraumatic stress disorder and generalized anxiety disorder, memantine was found efficacious in augmentation with other medications. In obsessive-compulsive disorder (OCD), memantine was used as both an augmentation to selective serotonin reuptake inhibitors and standalone therapy, and most published studies found it to improve OCD symptoms. For schizophrenia, memantine has been reported to be consistently effective for negative symptoms only. The manic phase of bipolar disorder also appears to benefit from memantine. The depressive phase of bipolar disorder and major depressive disorder did not respond significantly to memantine. Catatonia as a symptom of various disorders improved in several case studies when memantine was used in combination with other medications.
Conclusions: Memantine may have several therapeutic applications in psychiatry, reflecting the involvement of glutamate pathways in multiple psychiatric disorders.