Because treatment with ketamine might be so helpful to patients with treatment-resistant depression (meaning standard treatments had not helped them), the FDA expedited the approval process to make it more quickly available. In one study, 70 percent of patients with treatment-resistant depression who were started on ketamine improved, compared to just over half in the group that did not receive the medication (called the placebo group).

“This is a game changer,” says John Krystal, MD, chief psychiatrist at Yale Medicine and one of the pioneers of ketamine research in the country. The drug works differently than those used previously, he notes, calling ketamine “the anti-medication” medication. “With most medications, like valium, the anti-anxiety effect you get only lasts when it is in your system. When the valium goes away, you can get rebound anxiety. When you take ketamine, it triggers reactions in your cortex that enable brain connections to regrow. It’s the reaction to ketamine, not the presence of ketamine in the body that constitutes its effects,” he says.


And this is exactly what makes ketamine unique as an antidepressant, says Dr. Krystal.*