> Pharma companies don't benefit from getting Ketamine approved (since it's no longer patent protected), so no one is putting it through FDA for depression.
This is incorrect.
There are ongoing phase 3 clinical trials for nasally applied esketamine that will lead to FDA approval if succesfully reviewed. These trials are conducted worldwide and are very encouraging. The specific application seems to be patentable. First results should be available around 2019ish or 2020.
You can find the trials here:
https://clinicaltrials.gov/ct2/results?term=esketamine+depre...
And one of the patent applications here: