A depressant or central nervous system depressant is a drug or endogenous neurotransmitter that decreases activity in the brain through the lowering of neurotransmission levels, depressing or reducing arousal/stimulation in various areas of the brain. Depressants are occasionally referred to as "downers." Stimulants (or "uppers") which increase mental and/or physical function are in stark contrast to depressants and are considered to be their functional opposite.
Depressants are widely used throughout the world as prescription medicine and as illicit substances. When used, effects often include motor control loss, anxiety suppression, pain relief, sedation, somnolence, and cognitive/memory impairment. In some instances, the effects include euphoria, dissociation, muscle relaxation, decreased blood pressure, lowered heart rate, respiratory depression, anticonvulsant effects, and even complete anesthesia or death at high doses.
Depressants exert their effects through a number of different pharmacological mechanisms. The most prominent include the facilitation of GABA or opioid activity and the inhibition of glutamatergic or catecholaminergic activity.
The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. These effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances of inducing a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.
These effects are listed and described in detail within their own dedicated articles below:
The chemicals below have varying degrees of typical depressant effects.
- Depressant definition | http://wordnetweb.princeton.edu/perl/webwn?s=depressant