[pmoriarty]

Big pharma is not the main driver of ketamine use for treating depression right now, as it's no longer patented so nearly as profitable for pharmaceutical companies. There is a newly patented ketamine derivative called esketamine that is making inroads in to depression treatment, but plain old ketamine is still used quite a lot.

There are a couple of drivers of ketamine's popularity for treating depression:

First, it actually seems to work astonishingly well for a lot of people (certainly way better than standard antidepressants), though not for everyone.

Second, it's a big money grab for ketamine "therapists" (I use "therapists" in quotes because many of them just sit around while you get your injection, and don't actually provide much if any therapy) who can charge $500 or more per treatment (which usually isn't covered by insurance), and people often come back for treatment multiple times a week or month for long periods of time. The cost of ketamine itself in these treatments is negligible.

An interesting development in ketamine therapy is the use of ketamine lozenges, which patients can take at home and therefore are way cheaper than having a medical team inject you with ketamine in their office.