Answer:
A a drug that slows nervous system activity and relaxes tension
Explanation:
Depressants are chemical substances that directly affect the Central Nervous System, causing a slow or low brain activity and are accompanied by feelings of relaxation, like when drinking alcohol, a legal depressant , or benzodiazepines, that are commonly more known as sleeping pills, they cause drowsiness, lowering levels of blood pressure, and other drugs like barbiturates, often have a big sedative effect.
<em>Many different kinds of depressants include also substances coming from Opioids, for lessening pain, or Cannabis, commonly and recently studied for its Effects of Central Nervous System </em>
Since the Central nervous system depressants increase the production of the neurotransmitter GABA, the sensations often associated to the brain will be opposed to the other antagonic processes : stimulating drugs.