Ketamine's pain-relieving effects are not solely due to its dissociative properties. In an open-label study, 15 healthy adults received 2 mg/kg of ketamine, with midazolam given later to reduce dissociation. Statistical models showed that dissociation and pain intensity followed similar time courses, but when dissociation scores were added to the pain model, dissociation did not account for the pain relief. This indicates that ketamine's analgesic and dissociative effects are independent, suggesting ketamine can be used to study pain circuits separate from those involved in dissociation.
Ketamine given during general anesthesia reduces pain intensity by 3 points and increases dissociation scores by 17.8 points, but these two effects are independent: the pain reduction does not depend on dissociation. This suggests that ketamine's analgesic and dissociative properties involve separate brain circuits, even under general anesthesia, and that ketamine might be developed into a more targeted pain treatment without causing dissociation.