A preliminary study by researchers at the National Institute of Mental Health has found that a single intravenous dose of ketamine can provide symptom relief for some individuals with treatment-resistant depression (Zarate ZA et al. Arch Gen Psychiatry. 2006;63:856-864).
In the randomized, placebo-controlled, double-blind crossover study, 18 treatment-resistant depressed patients were assigned to receive either a single intravenous dose of ketamine or placebo. Ketamine improved depression symptoms within 1 day in 71% of patients receiving the drug, and 29% of these were nearly symptom-free.
While none of the patients in this study experienced serious adverse effects, ketamine (which is usually administered in higher doses as an anesthetic) is unlikely to become a widely used treatment for depression because of potential adverse effects, including hallucinations and euphoria. Ketamine blocks a neuronal protein, the N-methyl-D-aspartic acid receptor, which binds to and is activated by glutamate. . . . [Full Text of this Article]