Psychoactive drug

A psychoactive drug, psychopharmaceutical, or psychotropic is a chemical substance that changes brain function and results in alterations in perception, mood, or consciousness. These substances may be used recreationally, to purposefully alter one's consciousness, or as entheogens, for ritual, spiritual, or shamanic purposes, as a tool for studying or augmenting the mind. Some categories of psychoactive drugs, which are prescription medicines, have medical therapeutic utility, such as anesthetics, analgesics, hormonal preparations, anticonvulsant and antiparkinsonian drugs or for the treatment of neuro-psychiatric disorders, as hypnotic drugs, anxiolytic and some stimulant medications used in ADHD and some sleep disorders. There are also some psychoactive substances used in the detoxification and rehabilitation programs for psychoactive drug users.