Which effect is commonly associated with the use of CNS stimulants?

CNS stimulants are known for their ability to increase neurotransmitter activity in the brain, leading to heightened alertness and arousal. As a result, one of the most observable effects of using these substances is excitation, characterized by increased energy levels, heightened mood, and sometimes even euphoric feelings. This excitation is due to the stimulation of pathways associated with pleasure and reward, often making individuals feel more awake and focused.

In contrast, the other options represent effects that are typically associated with depressants or other categories of drugs. For example, slurred speech and flat mood are more characteristic of substances that depress activity in the central nervous system, while disorientation is often linked with substances that impair cognitive functions, such as sedatives or hallucinogens. This distinct profile of effects underscores why excitation is the most recognized outcome of CNS stimulant use.