Addiction <---> dependence + abuse
~dependence OR ~abuse <-----> ~addiction
BUT, dependence and abuse do not always go together.
Example: CP are dependent on drugs for pain relief, but they are not abusing the drugs.
ALSO: A person can abuse drugs without being dependent.
Therefore, the definition is wrong.
Cancer patient example is only relevant if we assume that the cancer patient is addicted.
Take notice of the conditional nature of the definition and the contrapositive. What the stimulus author is trying to do is undermine the definition and say that it doesn't apply to certain situations and is therefore wrong. So he employs certain examples to prove his conclusion. But what if the cancer patient ISN'T addicted...which would make perfect sense if he wasn't abusing the drug. His example serves to weaken the definition only if it runs contrary to our conditional statement. If we don't assume that the cancer patient is addicted, then we have not violated the statement either way.