Scientists have shown that ketamine damages young rats' brains at very high doses, but doctors in the US — including the American Society of Anesthesiologists and American Psychiatric Association — typically only change their clinical guidelines when they see harm in actual humans. Since nobody has documented that harm in humans receiving ketamine for depression or PTSD, these groups are unlikely to issue new warnings against the treatment.
Juvenile rat neurotoxicity models use doses and exposure windows non-translatable to adult human intermittent psychiatric dosing (typically 0.5mg/kg IV over 40 min, 6 sessions). The American Society of Anesthesiologists and American Psychiatric Association have historically required human epidemiological evidence or case series before amending practice guidelines. No such human dataset currently exists. Resolution criteria: absence of formal clinical guidance document from ASA, APA, or ASAM restricting ketamine use citing preclinical neurotoxicity by October 31, 2026.