What condition does a controlled substance alter in a person?

The correct choice is focused on the fact that controlled substances are known to have significant effects on a person's psychological state, specifically mood and perception. Many controlled substances, such as stimulants, depressants, and hallucinogens, can alter an individual's emotional state, influence their perception of reality, and change their cognitive processes. This leads to various behavioral and mental health effects, which may include euphoria, anxiety, distorted senses, and altered judgment.

In contrast, while substances might indirectly affect aspects like body weight or sleep patterns, those are not the primary conditions they are known to alter. Financial status is also not directly influenced by the use of controlled substances, although addiction can lead to financial difficulties over time. Therefore, the main impact of controlled substances lies in their ability to change mood and perception, making the first option the most accurate response.