Ketamine is great alternative for the person who is hooked on opiates [prescribe pain pills, heroine, opium...etc].
They are very similar in effect/s.
Current studies that show Ketamine is helping depression [socially, mentally, physically, AND spiritually].
Seeing as Ketamine effects are very similar in nature to heroine's; Ketamine's presence brings an entheogenic, life changing effect that opiates DO NOT have. Such as Introspective awareness of Yourself and surroundings, feeling of connectedness to Yourself and the world around You, Meaningful spiritual experiences, Visionary / dream-like Hallucinations or Imagination...etc. etc. etc. These are all psychedelic and entheogenic [healing] characteristics and principles.
Ketamine's sought after
non-psychedelic effects are very similar to any form of heroine or opium.
{Such as Euphoria, a pleasant body high, and pain relief...etc}
However, since Ketamine IS a psychedelic or "more entheogenic" substance, more than any form of opium or heroine...
It would make sense why ketamine is being looked into for depression;
as a healing, sacramental, entheogenic psychoactive substance.
source:
https://www.bluelight.org/xf/threads/ketamine-and-opiates.877376/