Depression effects 16.1 million adult Americans and is the leading cause of disability for people ages 15 to 44. Up to one third of those with this mental illness do not respond to approved medication, but in recent weeks there have been studies that have shown a possible solution: ketamine.

Usually ketamine is used as an anesthetic, or has been prescribed to treat chronic pain. But with low, intravenous doses (0.5 mg/kg), it has shown promising results. It had a 50-70% response rate that started as soon as two hours after treatment, and can last for up to two weeks.

There are concerns about the long term use of ketamine. Due to a lack of research, it’s hard to know if there are any dangers. A study done on rats exposed to high doses of ketamine resulted in the growth of white matter in their brains, so doctors and scientists aren’t too optimistic.

“So there is reason to believe that there is a point at which ketamine can become too much of a good thing, but we just don’t know what that threshold is,”said director of clinical research at the Nathan Kline Institute Dr. Dan Iosifescu

Despite this, there have been several suggestions to continue treating depression outside of ketamine. Psychotherapy after ketamine is one of these options; doctors hope the drug would hopefully motivate a patient enough to want to participate. Another option is for the patient to switch medication to currently approved anti-depression medication to continue the positive effects.

Though unapproved by the US Food and Drug Administration, the choice to use ketamine as a depression medication is seen as reasonable and there has been solid research on the short term use of it.

“The ketamine story is by no means finalized and ongoing research is focusing on addressing these questions,” Dr. Iosifescu said.

The future is looking optimistic for those who most medication hasn’t worked for. Besides ketamine, there is likely much more research on other drugs that will hopefully yield positive results for the world of medicine.