(~100k words, 3 hours; read MAPS-hosted ebook.) Everything ketamine (WP, Erowid).

Jansen begins with a short history of its discovery and diffusion into the psychedelic and club scenes, covers some of the more notorious cases, the neurobiology of ketamine as understood in 2004, and then a very long discussion of the similarities of near-death experiences with ketamine psychedelic trips, followed by thorough coverage of the notorious addictiveness of ketamine (which comes off a bit apologetic; ketamine strikes me as exceedingly dangerous if "In my opinion, the group who lose control over their use is unlikely to exceed 15% of those who find the experience rewarding", even if the biological dangers are minimal), then a bunch of ideas on how to treat ketamine addiction (some dubious, others common addiction strategies), a discussion of bad trips, and the existing body of work on using ketamine to treat addictions and other problems. It seems pretty thorough, even to a fault - I can't say I appreciated Jansen throwing in a bunch of quantum woo and half-baked speculation, but I suppose that's probably an occupational hazard (thinking the grand visions are anything more than grand visions and abusing physics).

It's also heavily leavened with excerpts from users' experiences, many interviews by Jansen himself apparently; these are good to have, but perhaps not as necessary as it was in 2004 now that the Erowid trip library has over 324 reports.

My own interest in ketamine is curiosity about the peculiar immediate anti-depressant effects it seems to have even with non-psychedelic use, but while depression is occasionally mentioned as a risk factor for ketamine abuse or outcome of abuse, it seems all the most relevant research must have been done after this was published in 2004.

Still, an interesting and excellent overview of a niche topic, and well worth reading for more in-depth coverage after reading an overview like the Wikipedia article.