I’ve seen “Mania” in older records. Usually it’s coupled with some other term, though. “Religious mania,” “sexual mania”; it makes me think that people who were once “manic” probably would be diagnosed with OCD now. I once read a case history of someone who, in the 1890s, was described as having a “mania” for dogs. I think now she’d be called a “hoarder.” IIRC the text, said something like “Her whole home was given over to the housing and husbandry of these animals, to the neglect of her own care.”
Hoarders usually have some kind of OCD. I worked with a few in community living. We would take them on only if they were in therapy and seeing a psychiatrist to work on their hoarding issues, because we didn’t need our agency to get sued when they trashed a rented house or apartment. Every one of them had some kind of diagnosis, and I’d say 85% had OCD. The rest had some kind of personality disorder, usually schizotypal, or schizoaffective.
Some people with OCD can be really hyperfocused on something, and have meltdowns when they get disrupted, which is a sort of manic-like behavior as well (they aren’t autistic, though, because the behavior usually didn’t manifest until adolescence or early adulthood). They are usually helped by a combination of drugs for OCD, which are often also antidepressants, but only a few very specific ones work for OCD (some, not all of the SSRIs, and for a few people, one of the tricyclics), and antianxiety meds. It’s really quite impressive the difference the drugs can make.
I think the problem is that “manic” is an old-fashioned term which is out of use, and even though Bipolar Disorder used to be called Manic-Depression, it’s a mistake to think of Bipolar Disorder as a euphemism. It’s a renaming to reflect better understanding. Major Depressive Disorder is a separate thing-- it’s not related just because it shares a word, just as Obsessive Compulsive Disorder, and Obsessive Compulsive Personality Disorder are two completely different things that happen to share some words.
I know a psychiatrist who says that sometimes you don’t know a depressed-presenting person has BPD until you prescribe an antidepressant, and they suddenly are whipped into a mania. It may be their first mania EVER, but that’s how you find out that all along it was BPD, and they need valproate, not bupropion.
So, basically, BPD people may be people who have atypical depression. That’s just a guess: IANAP