A couple of years ago Mr Dr Science & I read "Uncle Tom's Cabin" for the first time. We had heard of the character "Topsy", and that she was (racist, stereotypical) comic relief. To our surprise, she's actually a nearly-clinical depiction of attachment disorder -- Cliff's Notes gives a good summary.

Harriet Beecher Stowe clearly had seen attachment disorder and recognized where it came from -- though her readers, for the most part, *really* didn't want to. But it's at least one data point that says attachment disorder isn't a modern "invention", it happened in the past and could be perceived as a problem by people who cared to look.