Ketamine Analgesia and Psychedelia: Can We Dissociate Dissociation?

The ketamine chameleon: history, pharmacology, and the contested value of experience

INTRODUCTION

Since its synthesis in 1962, ketamine has been widely used in diverse medical contexts, from anesthesia to treatment-resistant depression. However, interpretations of ketamine's subjective effects remain polarized. Biomedical frameworks typically construe the drug's experiential effects as dissociative or psychotomimetic, while psychedelic paradigms emphasize the potential therapeutic merits of these non-ordinary states.

AREAS COVERED

Ketamine's psychoactive effects have inspired diverse interpretations. In this review, we trace the historical evolution of these perspectives - which we broadly categorize as 'dissociative,' 'dream-like,' and 'psychedelic' - and show how they emerged out of these clinical contexts. We highlight the influence of factors such as language, dose, and environmental context on ketamine's effects and therapeutic outcomes. We discuss potential mechanisms underlying these context-dependent effects and explore the broader clinical and research-related ramifications.

EXPERT OPINION

Ketamine's subjective effects are undeniably powerful, yet their therapeutic significance remains debated. A nuanced, interdisciplinary approach is essential for maximizing ketamine's potential. Future research should focus on how explanatory models, treatment environments, and patient preparation can optimize ketamine's benefits while minimizing distress. We suggest that, rather than being a tiger to be tamed as its creator once described, ketamine may best be understood as a chameleon whose color shifts depending on its context.

Phenomenology and therapeutic potential of patient experiences during oral esketamine treatment for treatment-resistant depression: an interpretative phenomenological study

BACKGROUND

Ketamine and its enantiomers are widely researched and increasingly used to treat mental disorders, especially treatment-resistant depression. The phenomenology of ketamine-induced experiences and their relation to its psychotherapeutic potential have not yet been systematically investigated.

AIMS

To describe the phenomenology of patient experiences during oral esketamine treatment for treatment-resistant depression (TRD) and to explore the potential therapeutic relevance of these experiences.

METHODS

In-depth interviews were conducted with 17 patients after a 6-week, twice-weekly 'off label' generic oral esketamine (0.5-3.0mg/kg) treatment program. Interviews explored participants' perspectives, expectations, and experiences with oral esketamine treatment. Audio interviews were transcribed and analyzed using an Interpretative Phenomenological Analysis (IPA) framework.

RESULTS

The effects of ketamine were highly variable, and psychological distress was common in most patients. Key themes included (a) perceptual effects (auditory, visual, proprioceptive), (b) detachment (from body, self, emotions, and the world), (c) stillness and openness, (d) mystical-type effects (transcendence, relativeness, spirituality), and (e) fear and anxiety. Key themes related to post-session reports included (a) feeling hungover and fatigued, and (b) lifting the blanket: neutralizing mood effects.

CONCLUSION

Patients reported several esketamine effects with psychotherapeutic potential, such as increased openness, detachment, an interruption of negativity, and mystical-type experiences. These experiences deserve to be explored further to enhance treatment outcomes in patients with TRD. Given the frequency and severity of the perceived distress, we identify a need for additional support in all stages of esketamine treatment.