AP Psychology Practice Test

Barbiturates primarily function as central nervous system depressants. Their primary effect is to reduce anxiety and promote sedation, which is achieved by depressing the activity of the central nervous system. This can lead to a lowering of inhibitions and an overall calming effect, making them useful in treating conditions like anxiety and insomnia.

However, their depressant effects also come with significant downside risks, such as impairing judgment, coordination, and memory. Regular use can lead to tolerance and dependence, exacerbating the potential for misuse. Barbiturates can suppress respiratory function at high doses, which is why their use is heavily regulated in a medical context.

Other options describe effects that are not characteristic of barbiturates: increasing anxiety and improving memory, for instance, is contradictory to their primary calming effects; stimulating neural activity and causing hallucinations are more associated with stimulants or hallucinogens; and while suppression of pain occurs in certain contexts, barbiturates are not primarily recognized for inducing hallucinations.