Excitation, increased alertness, and euphoria are symptoms of which category of substances?

Symptoms such as excitation, increased alertness, and euphoria are characteristic of stimulants. Stimulants are a class of substances that enhance alertness and energy, often elevating mood and increasing feelings of well-being. Common examples of stimulants include caffeine, nicotine, amphetamines, and cocaine. These substances work by increasing the levels of certain neurotransmitters in the brain, particularly dopamine, leading to heightened mood and physical responses.

In contrast, hallucinogens primarily alter perception, mood, and cognitive processes but do not typically cause the stimulating effects associated with euphoria. Depressants, on the other hand, have the opposite effect, generally reducing alertness and inducing relaxation or sedation. Benzodiazepines are a specific type of depressant that are used to treat anxiety and insomnia and do not produce feelings of excitement or euphoria.