This has been my experience too. None of the ketamine-based drugs have been as effective as regular ketamine. That said, drug companies will not seek to get regular ketamine FDA approved because they can't patent it. So this is the only way they will go through the process of FDA approval. I hope it leads to regular ketamine being FDA approved for treating depression because only then will it be covered by insurance.

The literature points to R-ketamine, on it's own, appearing to have stronger antidepressant effect, with less of the disassociative effects.

AFAICT, it's not patentable, so nobody would pay for the trials.

This is very true . R-ketamine holds most of the benefit but some of the metabolites of s-ketamine also do contribute to the positive effects .

Regarding patents . It is possible to patent an ROA method just like what j&j did with s-ket