Final answer:
Physical need achieved to a drug or alcohol is referred to as dependence, with physical dependence leading to withdrawal symptoms upon cessation. Addiction encompasses compulsive substance use despite negative consequences, and tolerance occurs when more of the drug is needed to achieve the same effects.
Step-by-step explanation:
When a physical need has been achieved to a drug or alcohol, this is referred to as dependence. Dependence on a substance can be either physical or psychological, but physical dependence involves bodily adaptation to the presence of the drug. Such adaptation results in withdrawal symptoms when the drug use is stopped.
Physical dependence involves the body's adaptation to a drug, requiring its presence for normal functioning and leading to withdrawal symptoms upon cessation. Psychological dependence, on the other hand, refers to the emotional need for a drug, often to relieve psychological distress. Addiction, which signifies the compulsive use of a substance like alcohol or drugs regardless of negative consequences, is a broader concept that may encompass both physical and psychological dependence.
Tolerance is closely tied to physical dependence. It occurs when a person needs an increased amount of the drug to achieve the same effects that were once reached with smaller doses. This phenomenon can lead to hazardous levels of consumption and even overdose. In cases of heroin addiction, the psychoactive drug methadone may be prescribed to manage withdrawal and reduce craving, due to its longer duration of action and less euphoric effect, which assists in the rehabilitation process.