Consent is not valid if the patient is under the influence or has impaired decision-making capacity.

• A. It is always valid
• B. False
• C. Only if the patient is a minor
• D. True

Answer: (D)

Valid informed consent hinges on decision-making capacity. A person must be able to understand the information, appreciate the consequences, reason about options, and communicate a choice. When someone is under the influence or has impaired decision-making capacity, that ability to understand and weigh risks and benefits is compromised, so the consent given is not truly informed or voluntary. Capacity is decision-specific and can vary with the person and the situation, so being a minor does not automatically render consent invalid, and other avenues (assent/parental consent or a surrogate) may apply where appropriate. In practice, if capacity is lacking, clinicians should seek a surrogate decision-maker or delay non-urgent treatment unless an emergency justifies implied consent.