physical dependence

Physical dependence on a substance is a physiological state where the body adapts to its presence, requiring it for normal functioning. This adaptation can lead to tolerance, where higher doses are needed for the same effect. If the substance is reduced or stopped, withdrawal symptoms like nausea and shaking can occur.1

This dependence is distinct from addiction, which is characterized by compulsive drug use despite harmful consequences and involves changes in brain reward and control pathways. While dependence can occur with prescribed medications used as directed, addiction involves a loss of control and continued use despite negative impacts. The term "drug dependence" is now often used to encompass the need for a substance to function.12