What is the primary effect of depressants on the central nervous system?

Depressants primarily affect the central nervous system by decreasing activity. This category of drugs includes substances like alcohol, benzodiazepines, and barbiturates, which operate by enhancing the effects of a neurotransmitter called gamma-aminobutyric acid (GABA). The activation of GABA receptors leads to a calming effect on the brain, resulting in a reduction of neural activity.

When depressants are ingested, individuals often experience relaxation, sedation, and a reduction in anxiety. This can be particularly evident in situations where a person might feel heightened stress or excitement. The decreasing effect on the central nervous system can also lead to slower reaction times and impaired motor skills, which is why caution is advised when operating machinery or driving under the influence of such substances.

In contrast, options that suggest increasing activity or stabilizing it do not align with the known pharmacological effects of depressants. Therefore, the correct answer emphasizes the fundamental characteristic of these substances in their interaction with the central nervous system.