Dr. Padma Gulur, a Duke University pain specialist, stands for a portrait on Friday, Oct. 27, 2023, in Durham, N.C. Prescriptions for ketamine have soared in recent years as doctors adopt the mind-altering drug as an alternative pain treatment. Gulur and other specialists see potential for ketamine as a pain therapy, but warn it also carries risks of safety and abuse. (AP Photo/Matt Kelley)