A dissociative substance is a substance that changes people's perceptions of sight and sound, causing someone to feel like they are being detached from themselves. An anesthetic is a drug that is designed to cause a temporary loss of sensation, including pain. Dissociative anesthetics target the central nervous system to change sensory stimulation, causing someone's senses to be significantly altered. People who use dissociative anesthetics often describe communing with a higher power or changing the way they see the world. Some people describe having the ability to look down on their own body as they receive treatment. There are numerous drugs that fall into this category, and many of them have different mechanisms of action. Most of the compounds have relatively quick times to onset, and then they leave the body just as quickly.