“Bipolar disorder is a disorder of mood regulation, and borderline personality disorder is a disorder of personality,” Hunter says. People with bipolar disorder cycle through extended periods of mania and depression, often accompanied by grandiosity or elevated self-esteem during manic phases. People with BPD, by contrast, often struggle with a persistent sense of emptiness and low self-worth, she says. And their emotional swings are more likely to be set off by something that happens—a perceived rejection, a fight, an unanswered text—than by an internal mood cycle.
Myth: BPD is always caused by childhood trauma
Trauma is a major risk factor for BPD; many people with the condition have experienced physical, sexual, or emotional abuse. But it doesn’t apply to everyone, and assuming it does can create problems of its own.
“This is not necessarily a trauma disorder,” Masland says. What’s more consistent, she explains, is a pattern of chronic emotional invalidation—growing up in an environment where big feelings were dismissed, minimized, or punished rather than helped. “You can imagine a child who has baseline high emotional intensity,” she says, “and the parent is not equipped to help with that emotional intensity. They may do things that are well-meaning, but still invalidate the child.”