Research recently published in the New England Journal of Medicine showed that the drug amantadine helped recovery of patients with severe traumatic brain injury. The study included 184 patients who were in a vegetative or minimally conscious state. After 4 weeks of treatment a significantly higher number of patients treated with amantadine recovered from coma than those treated with placebo. The improvement carried over to recovery of cognitive functions. It believed that amantadine improves recovery by increasing dopamine in the brain, which is a neurotransmitter.