Ketamine, a dissociative anaesthetic and phencyclidine derivative with known abuse liability, has shown rapid antidepressant effects in some clinical trials for treatment-resistant depression, but methodological flaws and possible reporting bias may have influenced those findings. Regulatory agencies have not approved ketamine for depressive disorders, and a Canadian review did not recommend its prescription. Off-label repeat prescribing raises ethical concerns, especially given the comorbidity of substance abuse with depression and the lack of evidence ruling out long-term abuse risk. Two clinical vignettes illustrate ethical principles—autonomy, nonmaleficence, fidelity, and consequentialism—relevant to off-label ketamine use. Clinicians should exhaust standard antidepressant therapies before considering ketamine.
A recently introduced list of operational indicators of consciousness, originally developed for challenging cases like non-human animals and artificial intelligence, may help address the high misdiagnosis rate among patients with disorders of consciousness. These indicators are particular capacities deduced from behavior, cognitive performance, or neural correlates, and they do not define a hard threshold for consciousness but allow graded inference based on consistency across indicators. Applying these indicators to disorders of consciousness could inspire new strategies for reducing misdiagnosis, establishing a gold standard for detecting consciousness, and refining the taxonomy of these disorders.