Really impressed that you were able to have it done in such a clinical setting. It's rare to find anywhere that will do that, or doctors who are open minded enough. Please keep us in the loop!
I have my doubts about one-off ketamine infusions for depression, unless it is extremely serious, suicidal depression with no alternative recourse. (Don't let me views impact you though. I don't have a lot to go on here and I've also heard stories that contradict my thinking.) The reason is that most of the research I've read about lasting relief for depression involves frequent low dosing, instead of one big dose. The bigger doses tend to have more temporary effects and need repeating 3 weeks - 1 month later. So I'd be curious to know what your symptoms are down the road. One complicating factor is your other drug use... that makes it hard to track the ketamine experience.
I made a
big thread about my self-experiments with ketamine for depression, based on research and networking with others at the time. I found the low dose protocol to have permanent results for myself. When I mixed it with anything else, even cannabis, the protocol got sabotaged.
The clinicians doing in-patient procedures like you had done, my impression of them is that they have good intentions. However, it's the culture of recreational ketamine use that prevents more ongoing out-patient treatment. In some districts, people have ketamine inhalers and nebulizers to give them a daily, low dose. But even those, from what I heard, hover around the 25-30mg mark, and patients are advised to stay indoors for at least two hours. My own experience + research has led me to strongly believe that anything above a threshold dose gets into "recreational use" territory - whether it's in a clinic or on your own - and this downgrades the therapeutic effect because of overstimulation of the NMDA receptors.
But... there are logistical, social, and legal problems to obtaining ketamine in a low dose formulation that can be administered daily. Frankly, if there were ever formulations in the 10-12mg range, we could have major impacts on depression. It's especially useful for people with PTSD and trauma related depression because those patients tend to have certifiable pre-frontal brain damage as a result of neurochemical changes due to trauma. Ketamine can correct these. I'm not sure about other kinds of depression.
There's also something to be said for the experience itself, going beyond the science. Depression is complicated and we can't boil it down to what's happening to a bunch of receptors. I've read reports of some people with serious, suicidal, intractable depression being given k-hole doses and their lives go from being beyond the pale to returning to relative normalcy. Surely it's the psychedelic experience itself that plays a part!