Depressant

A depressant is a drug that reduces the function or activity of a specific part of the body or brain. Due to their effects typically having a "down" quality to them, depressants are also occasionally referred to as "downers." Stimulants or "uppers," which increase mental and/or physical function, are considered to be the functional opposites of depressants. Depressants are widely used throughout the world as prescription medicines and as illicit substances. When these are used, effects may include anxiolysis, analgesia, sedation, somnolence, cognitive/memory impairment, dissociation, muscle relaxation, lowered blood pressure/heart rate, respiratory depression, anesthesia, and anticonvulsant effects. Some are also capable of inducing feelings of euphoria. Depressants exert their effects through a number of different pharmacological mechanisms, the most prominent of which include facilitation of GABA and/or opioid activity, and inhibition of adrenergic, NMDA, histamine and/or acetylcholine activity. Anaesthetics, sedatives, tranquillizers and alcohol are examples of depressants.

Indications
Depressants are used both individually and clinically for therapeutic purposes in the treatment of a number of indications, including the following :


 * To reduce feelings of anxiety and panic.
 * To induce sleepiness and relieve insomnia.
 * To induce analgesia and relieve aches and pains.
 * To reduce convulsions/seizures in the treatment of epilepsy.
 * To cause muscle relaxation for those with muscle pain or spasms.
 * To lower blood pressure and/or heart rate.
 * To boost the mood and/or enhance sociability.

Barbiturates
Barbiturates are effective in relieving the conditions that they are designed to address. They are also commonly misused, physically addictive, and have serious potential for overdose. When, in the late 1950s, it became clear that the social cost of barbiturates was beginning to outweigh the medical benefits, a serious search began for a replacement drug. Most people still using barbiturates today do so in the prevention of seizures or in mild form for relief from the symptoms of migraines.

Miscellaneous

 * Anticholinergics (Atropine, hyoscyamine, scopolamine, etc.)
 * Antihistamines (Diphenhydramine, doxylamine, promethazine, etc.)
 * Antipsychotics (Haloperidol, chlorpromazine, clozapine, etc.)
 * Beta blockers (Propanolol, atenolol, etc.)
 * Dissociatives (Dextromethorphan, ketamine, phencyclidine, nitrous oxide, etc.)
 * Muscle relaxants (Carisoprodol, cyclobenzaprine, etc.)
 * Nonbenzodiazepines (Zaleplon, zolpidem, zopiclone, etc.)

Opioids

 * Morphine
 * Heroin
 * Codeine
 * Hydrocodone
 * Oxycodone
 * Methadone

Combinations
Combining multiple depressants can be very dangerous because the central nervous system's depressive properties has been proposed to increase exponentially instead of linearly. This characteristic makes depressants a common choice for deliberate overdoses in the case of suicide. The use of alcohol or benzodiazepines along with the usual dose of heroin is often the cause of overdose deaths in opiate addicts.