The role of shame: why some people with bipolar disorder also carry borderline traits

Bipolar disorder and borderline personality disorder often show up together, and clinicians have argued for years about why. Are they overlapping diagnoses? Two separate conditions that happen to coincide? A study of 557 psychiatric outpatients in South Korea takes a different angle. Instead of asking which label fits, it asks which beliefs sit at the center of a person's distress, and how those beliefs connect to everything else.

A different way to look at symptoms

The work, published in the Journal of Affective Disorders, came out of Asan Medical Center, with Myeongkeun Cho as lead author and C. Hyung Keun Park as principal investigator. Every participant had a diagnosis of bipolar I or bipolar II.

The researchers leaned on two ideas. The first is the early maladaptive schema, a term from schema therapy for the deep beliefs we form when childhood emotional needs go unmet. Think of convictions like "I am defective" or "people I love will leave." They were measured across 18 categories. The second idea is borderline traits, broken into four pieces: unstable moods, identity confusion, stormy relationships, and self-harm.

Rather than averaging scores, the team used network analysis. Picture each symptom and belief as a dot, with lines drawn between the ones that move together. What you get is a map, and on a map you can see which dots are central, the ones that, if you tugged them, would shift much of the rest.

What sat at the center

Across the whole sample, three beliefs kept turning up in the middle of the network: shame and defectiveness, and subjugation, the habit of handing control to others [1]. These were not loose ends. They were hubs. Identity struggles and difficult relationships tended to bridge toward expectations of abandonment, abuse and isolation. Self-harm linked most closely to a felt lack of control over oneself.

Shame, in particular, behaved like a master switch. When a belief like that holds a central position, it pulls a long chain of other negative thoughts along with it. Research on how people manage those feelings in daily life points in a similar direction — studies on attachment anxiety and partner phone-snubbing find that people carrying deep worries about being unwanted are far more sensitive to signals of inattention, which is exactly the kind of abandonment expectation this network analysis highlights.

Severe and milder cases were not just the same thing scaled up

The researchers split participants into those with severe borderline traits and those with milder ones, and the two groups were wired differently.

In the severe group, unstable relationships were woven tightly into chronic negative beliefs, almost structural. In the milder group, relationship trouble looked more like fallout from mood swings, a consequence rather than a foundation. The pattern held for self-harm too. Severe cases tended to act outward when moods became unstable. Milder cases turned inward, into identity confusion, instead.

That distinction is practical. It suggests borderline traits in bipolar disorder are not one thing. Sometimes they grow out of long-standing beliefs. Sometimes they ride on top of mood instability. The treatment that helps probably differs depending on which you are looking at.

Where this points for therapy

If shame really does sit at the hub, then it becomes an obvious place to aim. Therapies that work directly on internalized shame, rather than chasing each downstream symptom, might shift more of the network at once. And tailoring the approach, belief-focused work for one profile, mood-stabilization-first for the other, fits the data better than a single protocol for everyone.

The caveats worth keeping

A map drawn at one moment cannot tell you what came first. This was a cross-sectional study, so we cannot say shame causes borderline traits; the arrow could point the other way, or both could share a root. The sample came from a single medical center in one country, so it may not travel to other cultures or clinics. Medication and current mood state were not accounted for, and both could color the picture.

What it offers is a hypothesis with shape: that shame is not one symptom among many but a load-bearing beam. The next step is the harder one, following patients over time to see whether loosening that beam really does bring the rest of the structure down with it. Understanding how unmet emotional needs drive behaviour also sheds light on patterns like compulsive binge-watching fuelled by loneliness and the search for comfort — a different surface presentation, but the same dynamic of pain seeking an outlet. For more research connecting early beliefs to adult psychological patterns, the evidence continues to build.

Sources

1. Cho, M., Park, C., Lee, E., & Park, C. H. K. (2026). Levels and associations of borderline personality features and early maladaptive schemas in bipolar disorder: A comparative network analysis of patients with and without severe borderline personality features. Journal of Affective Disorders. https://doi.org/10.1016/j.jad.2026.121174

This article summarizes published research for general informational purposes only. It is not medical advice and should not be used to guide treatment, diagnosis, or other health decisions. Speak with a qualified healthcare professional about any health concern.