Final answer:
Drug abuse is the nonmedical or improper use of a drug, often leading to addiction and dependence. It involves use without medical guidance. Rehabilitation may include therapy and medication.
Step-by-step explanation:
Drug abuse is defined as the nonmedical or improper use of a drug, which can interfere with a healthy life. This practice involves using drugs without the advice of a medical professional and for reasons not intended by the drug's original purpose. Psychoactive drugs, which can alter mood, perceptions, thinking, and behavior, often have the potential for misuse and addiction. Drug abuse can lead to drug addiction, a condition characterized by compulsive use of a substance despite the negative consequences that such use may entail. The sustained use of an addictive drug may produce physical or psychological dependence, and stopping drug use may result in withdrawal symptoms. Rehabilitation often involves psychotherapy and may also include the temporary use of other psychoactive drugs to ease withdrawal symptoms.