For what purposes are depressants commonly used?

Depressants are commonly utilized for several therapeutic purposes, primarily focusing on alleviating anxiety, aiding sleep, and providing pain relief. These substances work by slowing down the central nervous system, which can help individuals manage symptoms of anxiety disorders, insomnia, and certain types of pain.

Anxiety relief is a significant use of depressants; medications like benzodiazepines can effectively reduce feelings of tension and worry. For sleep aid, drugs such as barbiturates and certain benzodiazepines are prescribed to help individuals struggling with insomnia by inducing a calming effect that facilitates easier onset of sleep. Furthermore, certain depressants are useful for pain management in conditions where other types of pain relief have proven inadequate.

In contrast, the other options involve uses that do not align with the primary applications of depressants. Weight loss and performance enhancement typically relate to stimulants or other substances that increase metabolic rates or energy levels. Muscle building and energy boosting pertain more to anabolic steroids or stimulant medications that promote performance and recovery. Hallucination and perception alteration are generally associated with psychoactive substances known as hallucinogens, which have a very different mode of action compared to depressants. Thus, option B accurately captures the key therapeutic applications of depressants in medical contexts.