Answer:
Psychoactive Substances
Psychoactive substances are substances that, when taken in or administered into one's system, affect mental processes, e.g. cognition or affect.
Psychoactive substances often bring about subjective (although these may be objectively observed) changes in consciousness and mood that the user may find rewarding and pleasant (e.g., euphoria or a sense of relaxation) or advantageous in an objectively observable or measurable way (e.g. increased alertness). These substances may be used medically; recreationally; to purposefully improve performance or alter one's consciousness; as entheogens for ritual, spiritual, or shamanic purposes; or for research. Some categories of psychoactive drugs, which have therapeutic value, are prescribed by physicians and other healthcare practitioners.
Substances which are rewarding and thus positively reinforcing have the potential to induce a state of addiction – compulsive drug use despite negative consequences.
Examples: alcohol, caffeine, nicotine, heroin, LSD, cocaine, and amphetamines, marijuana, and certain pain medicines
7 MAJOR CLASSES OF PSYCHOACTIVE SUBSTANCES:
1. Central Nervous System (CNS) Depressants
CNS depressants slow down the operations of the brain and the body. Examples: alcohol, barbiturates, anti-anxiety tranquilizer, GHB (gamma hydroxybutyrate), Rohypnol, and many other anti-depressants (e.g., Zoloft, Paxil).
2. CNS Stimulants
CNS stimulants accelerate the heart rate and elevate the blood pressure and "speed-up," or over-stimulate, the body.
Examples: cocaine, amphetamines, and methamphetamine.
3. Hallucinogens
Hallucinogens cause the user to perceive things differently than they actually are.
Examples: LSD, peyote, psilocybin and MDMA (Ecstasy).
4. Dissociative Anesthetics
Dissociative anesthetics include drugs that inhibit pain by cutting off or dissociating the brain's perception of the pain.
Examples: PCP, its analogs, and dextromethoraphan.
5. Narcotic Analgesics
Narcotic analgesics relieve pain, induce euphoria, and create mood changes in the user.
Examples: opium, codeine, heroin, demerol, darvon, morphine, methadone, Vicodin, and oxycontin.
6. Inhalants
Inhalants include a wide variety of breathable substances that produce mind-altering results and effects.
Examples: Toluene, plastic cement, paint, gasoline, paint thinners, hair sprays, and various anesthetic gases.
7. Cannabis
Cannabis is the scientific name for marijuana. The active ingredient in cannabis is delta-9 tetrahydrocannabinol, or THC.
Examples: cannabinoids and synthetics like Dronabinol.
