dependance

Dependance, also spelled dependence, is a state of reliance on someone or something for support, existence, or function. The term is used in many fields, and its precise sense depends on the context. In everyday use it often refers to emotional or economic reliance, while in professional contexts it may describe physiological, psychological, or statistical relationships.

Etymologically, dependance derives from Latin dependent-, and through Old French and English, the root ideas of hanging from or relying on. In modern English, dependence is the more common spelling in American English for the noun, while dependance appears less frequently and may be encountered in older or regional texts.

In medicine and psychology, dependence has specific technical meanings. Physical dependence is an adaptive physiological state in which withdrawal symptoms occur if the substance is reduced or stopped. Psychological dependence refers to emotional or cognitive reliance that can reinforce continued use or behavior. These notions are distinct from addiction, which also involves compulsive use and behavioral patterns beyond physiological adaptation.

Other domains use the term to describe relationships of reliance. In statistics, dependence denotes a relationship between variables where knowing one variable provides information about another, i.e., the variables are not independent. In computing, dependencies are external components or libraries required for a program to run. In ecology and social science, dependance can describe how organisms, systems, or individuals rely on resources, structures, or supports.

Overall, dependance captures the broad idea of reliance, with discipline-specific nuances and implications for autonomy, vulnerability, and system function.