Drug abuse occurs when legal or illicit substances are used inappropriately. This can involve exceeding recommended medication dosages or using someone else's prescription. People may misuse drugs to experience euphoria, reduce stress, or escape from reality. The term drug tolerance in psychology pertains to the body's ability to adapt to a substance based on genetic factors and adaptive changes. These adaptations develop in response to repeated exposure to a specific drug, often resulting in a reduced sensitivity or responsiveness to the drug, which is known as tolerance.