Since gaining FDA approval in 1970, ketamine has successfully been used as an anesthetic in hospitals and emergency rooms across the country. Though sometimes used as a “psychedelic club drug,” ketamine continues to have an incredibly safe track record. It’s even used on children who come into the ER with broken bones, explains one NPR article.

But could it be used as an effective treatment for depression? This is the question many psychiatrists throughout the country are asking, specifically because of some research that has already been done on the drug. Unfortunately, without FDA approval, people living with depression cannot receive the drug as a prescription—a prescription that some are considering the best option for those in which all other treatments have failed.

As you may know, depression can be an incredibly debilitating mental condition for some individuals. In some cases, normal medical treatments simply aren’t enough or are altogether ineffective. According to a 2015 article for Nautilus, one reason this could be the case is that current treatments consider mental health disorders like depression to be a chemical imbalance. But it’s in the opinion of some doctors that depression could be a result of structural changes in the brain due to stress.

As the author of the Nautilus article explains, stress is believed by some to damage the neurons in our brains. Ketamine, some doctors believe, “acts to strengthen the neuron against that damage.”

Though ketamine injections have shown promising results in some patients, the drug has two major downfalls. First of all, it doesn’t work as an effective treatment for all patients. And second, because the drug is still considered experimental, most insurance companies will not cover its cost, which can be incredibly expensive.