It seems like some psychiatrists view self injury as enough evidence to strongly suspect borderline personality disorder. It’s extremely fucked up but IME there doesn’t seem to be much emphasis on ruling out past abuse first.

I’ve had narcolepsy since early high school but I was misdiagnosed with psych issues for like 9 years before ever being sent to a sleep specialist. Most doctors I’ve seen since have accepted the newer diagnosis, even if they hadn’t known before that narcolepsy and depression could look so similar (oversleeping, lack of energy, not enjoying things as much, anxiety from pushing myself so hard to do things despite being so sleepy, etc). A good psychiatrist was actually the one that set me on the path that led to my narcolepsy diagnosis—he recognized that the only med I responded to was Wellbutrin, but that I needed a stronger effect while already near the max dose. It suggested stimulants might help more, but that didn’t make sense at the time. He suggested a thorough physical to rule out any physical health problems.

The primary care doc who did the thorough physical was actually one of the most skeptical when I saw her again a decade later. She followed through on all the various issues I was having, which is how I eventually ended up seeing a sleep doc, but when I went back to her years later she was extremely skeptical that narcolepsy could’ve been confused for depression and didn’t seem to believe it was plausible despite the conclusive sleep study and massive improvement with narcolepsy-specific treatment. By that time I’d seen 5 sleep specialists/neurologists (moving, being referred to docs with more specific treatment experience etc), all of whom agreed on the diagnosis, but this primary care doc still had an attitude about the idea.

I also saw a young male psychiatrist once to rule out bipolar disorder once when a narcolepsy med had stopped working in a very unusual way (eventually learned I’d developed gastroparesis, and the med required an empty stomach to work). He did rule out any concerns like that, but his assessment flagged cluster B personality disorders because I’d self injured in the past. He never asked about abuse issues, never probed into what I saw as my masochism, etc. Self injury was enough to mention cluster B personality disorder in his assessment, with BPD being the only one that could possibly have fit. I was (and still am, honestly) livid at how irresponsible it was for him to make that leap with so little consideration. A BPD diagnosis could’ve been enough to derail my narcolepsy treatment, whether it fit or not.

FWIW, that psychiatrist didn’t last long. Even working in an area with a massive shortage of psychiatrists. He was in charge of the psych unit my grandfather stayed in when a med he was taking to help with his (probable) Lewy body dementia seemingly triggered mania and made him start admitting all the delusions etc he’d been hiding from us. Once he was admitted to the psych floor, they put him on Zyprexa, and even though it was causing very clear Parkinson’s-type side effects (pill rolling tremor, all the muscles in his body were tended to the point he was sweating, struggling to speak, etc), it took over a week of his neurologist calling to get them to stop the med. His neurologist was pretty irritated about it, and we were furious. It wasn’t a med that should’ve ever been tried first thing in an elderly dementia patient, and having him taken off it shouldn’t have taken so much fuss.

TL;DR: psychiatry desperately needs more objective standards and tests, because shitty psychiatrists don’t know what the fuck they’re doing and having diagnoses that can’t ever be solidly ruled out is a recipe for disaster.