"Even if one claims that an addiction is purely psychological, by this implying that it is the patients fault of having a weak will and he or she should take responsibility for getting out of the mess"

addicts don't necessarily have weak will, their just self medicating to deal with things like depression for example. also they should take responsibility to get out of their addiction, how else would they get out of it.

that's the problem when it's looked at as purely physical, it makes people like AA say your powerless over it, when yes you may need outside help, but to say powerless is false and probably only puts addicts in a self fulfilling prophecy when there thinking 'i can't do anything about it.'

by that logic because depression makes changes in the brain then those changes are the reasons for depression ( the chemical imbalance theory of depression is bs look it up), but as the basic rule of science states, correlation doesn't equal causation.

also i'd like to note everything causes physical changes in to the brain, including your own thoughts.