Table 2.

Themes, codes, example quotations.

1. Multifaceted motivations for seeking ketamine in a clinical trial
Concern over alcohol use and health	“I was aware I was drinking too much, and it looked like a very interesting way of beginning to address it.” (P13)
Hitting rock bottom	“.for me, it was kind of it felt like kind of like the last chance saloon really to kind of do something.” (P09)
Altruism	“… I thought what if the ketamine trial proves successful and you know it just saves one life, someone who might die because of alcohol dependency issues, and then it is worth my continuing.” (P04)
Legitimacy of the trial and curiosity	“I used to have a personal trainer and I noticed he posted on Facebook actually the KARE trial was happening. And that's why I saw about it and I just got intrigued by it.” (P11)
2. Set and Setting as influential in determining acute ketamine experiences
Set	“. I've done that before with ketamine but in a gang of friends, which is kind of what you do with friends and it's all a bit sloppy and daft after a big techno night and it's not something I've done much in the last five years before the trial anyway. But you know, I do know that world and they're lovely” (P06)
Setting	“I had no idea what would happen. but then after that, the second and third I sort of went into the sessions with more intent to explore and to get answers from certain things. it was nice to just do that and know that you're in a safe environment and you can come out the other side. It filled you with confidence and you know there's no paranoia.” (P10)
3. Inherent contradictions of acute experience
Positive effects
A. Calmness and relaxation	“It was peaceful. It was calming and I just sat back and. you know, I didn't lose sense of who I was. I always knew who I was, and I had confidence that this would be temporary.” (P04)
B. Reinforcing effects	“I wanted this to carry on every week for the rest of my life. I wanted this experience in this, you know, sort of clinical place, I would still be coming now you know what I mean?” (P05)
Negative experiences
A. Fear or panic	“I knew where I was, but I just, it wasn't a pleasant experience like the first one and then the end part, the second one. It was, it was scary. And to the point of when you're on it, you barely breathe, you've quite shallow breathing.” (P03)
B. Paranoid ideation	“So it was a sort of mixture of extreme comfort for want of a better word with a sort of paranoia where one's brain is saying, if you guys in the room will leave the room, I'm stuck here for the rest of my life, sort of thing.” (P02)
C. Paralysis	“It's almost like a state of paralysis, where you do receive visual and sound information. But I don't know how much sense I was making to the people in the room around me. It feels like when you try and run in a dream, but your legs are move fast enough. In fact, exactly like that.” (P08)
D. Nausea and vomiting	“I was I didn't feel particularly brilliant, to be honest. And then I started moving and just was aware I was going to be sick. And then I was quite violently sick. So that was my experience.” (P13)
Otherworldly experiences	“Well, that infusion took me somewhere that was out outworldly, was out of this world. It was not—it was not within this world.” (P05)
Dissociation, detachment, and floating	“… as far as I was concerned that was it. I was done. My human body wasn't—I didn't have a human body. I was something… And even though I knew that I was kind of tethered, I didn't know how I was going to get back to my body.” (P05)
Ego dissolution	“The experience was genuinely remarkable in terms of the both the visual effects and…. the sort of removal of ego that accompanied that. I felt that I was one with the whole universe and it sounds hippy dippy but that's how I felt. I think I related to this sort of ego changing, the size of the ego in me as well as a sort of physical sensation.” (P07)
Changes in experiences over time	“So, the first one was very trippy and like going into another dimension. And then the second one, because I wanted to go into that dimension, I think I was trying to go there and then I got a bit sort of like, oh, I can hear voices. This is putting me off. And then the third one. I wasn't well at all after that. As I said I couldn't come around from it.” (P03)
4. Rapidly fluctuating and changing experiences
Perceptual distortions
A Visual distortions	“I remember looking at the light above my head in the window and sort of blinking and as I blinked the of the colours changed. Even though. the picture in my mind, the light in the window was the same.” (P07)
B Auditory distortions	“.there were pieces that I was familiar with, but they were just, they were coming—It's like different aspects that made up the piece were coming through a different speeds or different pitches. They were just sounding like unique. … I could still hear them as piano pieces but they weren't the pieces that I knew.” (P04)
C Hallucinations or visions	“I saw.this very strong vision of the synapse travelling across the neural pathway, then me typing into my phone, him getting the message him talking to someone else, and like this chain of communication, essentially that got bigger and bigger and bigger and bigger and bigger, to the point where it zoomed right out and you're seeing the earth hanging there in space along with say 20, 25, 30 other inhabited planets all there in the cosmos.” (P09)
5. Meaningful, spiritual, and mystical experiences
Ego dissolution	“It was a sense of completeness sense of, I suppose in a way finality, a source of finish. But also, a sense of enormous growth and a feeling of oneness with other entities, other living beings in particular, but also the world and universe as a whole.” (P.07)
Epiphanies and Enlightenment	“I think the first two like, they sort of left me… like they answered a lot of questions. You know, thinking about my children and I have a stepdaughter and… It was things about that. And about, you know what I should be doing and how I should be, you know, I don't know it seemed to be like all the things that are really heavy on my mind and that I stress about whatever it was sort of going through those things.just realising how little importance some things had or were.” (P10)
Transcendence of time	“.while we're on the subject of time. I mean, that just goes bananas and I love it. It's almost like. this afternoon, this evening, the way we think of that—That just blows apart and doesn't exist anymore.” (P06)
Hallucinations or visions	“I was lying there, and there was this, there was this like a cacophony coming from the hallway, everyone was going like, like he's coming he's coming! And I was like what's going on, you know, like thinking this shouldn't be happening in the hospital, I thought this is a peaceful place and everyone's like rushing out into the hallway to see what's happening. And it's this cartoon very simply drawn constructed of neon light rendering of God, essentially is walking down the corridor.and he came up to me and he was like.you can ask me two questions.” (P09)
6. The ketamine infusions and the trial as transformational
Perspective on life	“It helped family wise, relationship wise in every, every single avenue of my life. It's changed it.doing the ketamine and seeing this other dimension enforced my belief of another life and I now live every single day to the max. When I go for a walk, I'm very observant of my world around me. I take pleasures in life rather than pleasures of.drink. So.it's still with me and I hope it'll stay with me for forever.” (P03)
Relationship with alcohol	“I think before the trial all my life was sort of focused around alcohol. I was either drinking it at home or selling it to students or working in an event where there was alcohol, the alcohol was a focus of it. So it was sort of everything and then afterwards, it just sort of stopped. I enjoy a drink every now and then, but under much safer ways really.So it just made me realise I don't need to sort of drink to excess because there's nothing else to do. I can just do other things.and that alcohol isn't everything.” (P12)
Positive experiences of psychotherapy and alcohol education	“You definitely need that support system. It feels like that you get with the therapy and the fact that you can take that home with you as a crutch. So yeah, it was, it was very good, obviously painful in some parts, but you know I was at my most. desperate. I wouldn't be here now, if it wasn't for it. I can definitely say that.” (P03)
Interaction of ketamine with psychotherapy or education
A. Ketamine interacting with psychotherapy or education	“If I had just gone to education sessions and gone: ‘oh well I work around alcohol all day, I am pretty sure I know all the stuff I need to know about it,' I probably wouldn't have listened so deeply. But the ketamine sort of made me more willing to engage with it” (P12)
B. No impact of ketamine on psychotherapy or education	“I don't think there was any correlation there because the effects had fully worn off before we would go into that kind of conversation.” (P08)
Ketamine and talking sessions as mutually supportive	“I was kind of more open to understanding those mental and physiological impacts of alcohol because of the mental effects I've had from the ketamine. Um, so I think there was there was a sort of mutually supportive relationship between both elements to the therapy.” (P07)
Non-specific trial effects	“It's more the sort of holding hands that one needs, you need somebody who you've sort of divulged all your innermost secrets to. Having done that, it then sort of makes you think twice about buying that bottle of wine. It's that sort of attention that you get that I think is valuable in this sort of thing.” (P02)