Esketamine, a Johnson & Johnson antidepressant based on the party drug ketamine, has received backing from an FDA independent advisory group, removing one of the final hurdles to full clinical use. The advisory group voted 14-2 in favour of the drug, despite questions still remaining about its potential for abuse.

While it’s uncertain yet how ketamine works in the brain, since the 2000s scientists have known that it alleviates symptoms of depression very quickly, and in a way entirely different to that of other drugs purported to achieve the same outcome.

Ketamine is currently approved for use as an anaesthetic, but cannot be patented. Because of this several companies are already looking at compounds mimicking the structure of ketamine to patent. The J&J variant esketamine contains only one version of the molecules comprising ketamine.

Of five phase 3 trials of esketamine, only two showed positive results, with test patients improving only slightly more than those who received a placebo. Despite this, those advisory group panellists who voted in favour of the drug cited considerations including patient preferences and the fact that at least some people would benefit from approval.

The FDA is set to make a decision on the drug by 4 March 2019.