Which of the following best defines the term "psychoactive" and correctly identifies two examples of psychoactive drugs?

• A. A psychoactive substance is a chemical that enhances muscle growth and physical performance; examples include creatine and protein powder.
• B. A psychoactive substance is a medication used exclusively to treat infections; examples include penicillin and amoxicillin.
• C. A psychoactive substance is a chemical that alters brain function, resulting in changes in perception, mood, or behavior; examples include caffeine and LSD.
• D. A psychoactive substance is a drug that only affects physical health without influencing mental states; examples include aspirin and ibuprofen.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the term 'psychoactive' by breaking down its components: 'psycho-' refers to the mind or mental processes, and '-active' means having an effect. Therefore, a psychoactive substance affects the mind or brain function.
2. Step 2: Recognize that psychoactive substances alter brain function, which can lead to changes in perception, mood, consciousness, cognition, or behavior.
3. Step 3: Evaluate each option by checking if the substance described affects mental states or brain function, rather than just physical health or bodily performance.
4. Step 4: Identify examples of psychoactive drugs by considering substances known to influence mental processes, such as caffeine (a stimulant) and LSD (a hallucinogen), which alter perception and mood.
5. Step 5: Conclude that the correct definition of 'psychoactive' is a chemical that alters brain function, resulting in changes in perception, mood, or behavior, with caffeine and LSD as appropriate examples.