Addictionhas been defined as dependence on and abuse of a psychoactive substance.  Dependence and abuse do not always go hand in hand, however. For example, cancer patients can become dependent on morphine to relieve their pain, but this is not abusing the drug. Correspondingly, a person can abuse a drug without being dependent on it. Ttherefore, the definition of addiction is incorrect.
 The assumption that cancer patients who are dependent on morphine are addicted to it is relevant to the argument.