Ketamine blocks the NMDA receptor, which is thought to be the receptor that causes memory formation. So it is expected to affect memory. The brain damage effec

Ketamine blocks the NMDA receptor, which is thought to be the receptor that causes memory formation. So it is expected to affect memory. The brain damage effect is uncharacterized in humans. Several NMDA drugs cause this effect in rats, but none of them have been found to cause devastating problems in humans except PCP. There is some suggestion that opioids cause cancer, but the only study was small and observational.