What is the definition or description of: substance dependence?

Short answer: The 2 defining characteristics are uncontrolled use of a substance i.e. Only intended to have 2 drinks after work and had six, and continued use despite negative consequences, causing conflict with others, missing obligations, causing finacial problems, neglecting ones own health. Usually when someone is very active in this disease they have difficulty seeing either of these problems, denial.

See below: There are lots of definitions but I have my own informal definition : 1- the use of the substance is causing a net harm to your life. 2- the person recognizes the harm 3- the person can't or won't stop the substance.