Yep, exactly. Sure, I've left out medical reasons but principally it's not what most people have in mind when they talk about 'doing drugs' - even replacing aspirin with something psychoactive (e.g. SSRIs or anti-psychotics).

My point was in response to the parent's 'is it so much different really' question - when you insist that all varieties of reasons that people might be ingesting psychoactive substances stay under the same banner it's a fair bit harder to have a useful conversation about it.