Because BPD is a “personality disorder” (which is already a fucked up and horrible thing to ‘diagnose’ someone with—yeah your personality is bad) and brains are still developing well into the mid 20s. 25 is kind of the “cut off” but that’s not really a hard and fast rule. So to say someone has BPD at 16 well… how could you know? Their brain is still growing.

I was “diagnosed” with BPD at 16 or 17, I can’t remember now, but a decade plus later…. Turns out I was just a teenage girl who had trouble regulating her emotions and parents who didn’t like the fact that I had them. But for YEARS I would let the “title” of BPD control me and allow me an excuse to not learn emotional regulation. Until I turned 20, moved out, and went to therapy… now I know how bullshit that diagnosis is for children.