I'll take this sincerely, and ask you, is this really something you've a continuing curiosity about? I have a suspicion you understand what is taking place, but for whatever reason, are not expressing so directly. Are you asserting there is nothing more to discuss after one parses the search results for “chemical imbalance debunked”. The parent is quite clearly, at the minimum, meeting their parent's level of input, which essentially amounted to "this thing is debunked". As an onlooker and after a quick skim of the search query you suggested, I am still not exactly clear on what "neurochemistry issue [theory]" entails. What would help, is a more clear underpinning for what is being discussed, which your parent is suggesting, through question, before attempting to respond. I appreciate this personally!