I never said they are interchangeable and that was a theoretical road of the implications of drug use. Many people, pain patients such as yourself, can draw the line at dependence, not allowing it or its consequences to deteriorate. This requires discipline, self control, and biological factors have to be favorable. If biological factors are against you, and you do not possess discipline, then the opposite is likely to happen. These substances are dopaminergics, a hormone that controls reward and pain, its only natural that if your body becomes accustomed to it coming from a substance that you'll rely on it and only it for these feelings even after the pain is gone and you no longer need them for a legitimate medical purpose.
I think you don't understand addiction just as much as those who have attached this stigma to you.
Again, dependence is just one component of addiction. Understand it whichever way you like, but I really hope that you acknowledge that just because you don't exhibit any traits of an addict, and just because your using substances for medical purposes does not make you immune to addiction.
Also, if you have a legitimate medical condition, your medications are prescribed under the recommendation of a physician, then why is the stigma bothering you. It's generally people who want the medications, that are trying to prove their pain which at times is legitimate that have to go through this discrimination.