Review of adjunctive glutamate antagonist therapy in the treatment of catatonic syndromes.

Catatonia is a common neuropsychiatric syndrome which may arise from GABA-A hypoactivity, dopamine (D2) hypoactivity,and possibly glutamate NMDA hyperactivity. Amantadine and memantine have been reported as effective treatments for catatonia in selected cases, and probably mediate the presence of catatonic signs and symptoms through complex pathways involving glutamate antagonism. The authors identified 25 cases of catatonia treated with either agent. This article provides indirect evidence that glutamate antagonists may improve catatonic signs in some patients who fail to respond to established treatment, including lorazepam or electroconvulsive therapy. Further study of glutamate antagonists in the treatment of catatonia is needed.