A growing number of small clinical trials have demonstrated that subanesthetic doses of ketamine can produce antidepressant effects in patients with mood disorders who have demonstrated refractoriness to standard therapies.1 Patients in these trials have been diagnosed with major depressive disorder and bipolar disorder, and the sample sizes have ranged from 8 to 99. While there is broad agreement that ketamine-like drugs hold considerable promise as novel antidepressant agents, the increasing number of clinicians from a variety of medical specialties offering ketamine as an off-label treatment for psychiatric disorders2 has raised concern.