Why This Matters
If you have read about BPD and felt that some of it sounds like you but not all of it — that is not unusual. BPD often shares symptoms with other mental health conditions, which makes it one of the most misdiagnosed disorders in psychiatry. Understanding the overlap is not about adding more labels. It is about helping you and your sisters find the right kind of care, inshaAllah.
How Common Is the Overlap?
Research consistently shows that around 85% of people diagnosed with BPD also meet the criteria for at least one other mental health condition at some point in their lives. The most common ones are:
- Depression (Major Depressive Disorder)
- Anxiety disorders, especially generalised anxiety and social anxiety
- Post-Traumatic Stress Disorder (PTSD)
- Bipolar disorder — particularly Bipolar II
- Eating disorders
- Substance use difficulties
One review found that people with BPD had an average of 4.1 lifetime co-occurring conditions. This is not a sign that something is "extra wrong." It is a sign that the emotional system is under strain from many directions, often for many years.
BPD vs Bipolar Disorder — The Most Confused Pair
This is probably the overlap that causes the most confusion, so it deserves its own moment.
Both conditions involve mood swings. But they are not the same. A peer-reviewed review published in 2023 in Cureus explains the difference well:
- Bipolar disorder involves mood episodes that last for days or weeks — long periods of depression or mania.
- BPD involves mood shifts that last for hours to a day or two, usually triggered by something in a relationship or sense of self.
About 20% of people with BPD also meet the criteria for bipolar disorder, and roughly the same percentage of people with Bipolar II also meet the criteria for BPD. When both are present together — sometimes called "borderpolar" in clinical writing — the journey can be more complex, but recovery is still possible with the right treatment.
BPD and PTSD
Childhood trauma is one of the most studied risk factors for BPD. So it is not surprising that PTSD and BPD frequently appear together — research suggests the overlap is significant, especially among women who experienced abuse or neglect in childhood. The symptoms can look similar (flashbacks, emotional numbness, hypervigilance), but a trained clinician can tell them apart and treat both.
Why Accurate Diagnosis Matters
This is the heart of why this reflection exists. Mistreating the wrong condition can make things harder. For example, antidepressants alone often disappoint when the underlying issue is BPD — but the right kind of therapy (DBT, MBT, schema therapy) can be life-changing. Bipolar disorder usually responds well to mood-stabilising medication; BPD responds better to specialised psychotherapy.
A sister who has been told "you have depression" for ten years, when she actually has BPD, may have spent a decade on the wrong treatment. That is why this matters. Not for the label. For the care.
A Word of Care
If any of this resonates, please do not try to diagnose yourself from a website — not this one, not any other. Speak with a qualified mental health professional who can sit with your full story. Your experience is more than a checklist, and you deserve to be seen as a whole person.
Sources & Further Reading
- Ruggero CJ, et al. "Borderline personality disorder and the misdiagnosis of bipolar disorder." Journal of Psychiatric Research, 44(6):405–408, 2010.
- Shah R, Zanarini MC. "Comorbidity of borderline personality disorder: current status and future directions." Psychiatric Clinics of North America, 41(4):583–593, 2018.
- Bayes A, et al. "Bipolar Disorder and Borderline Personality Disorder: A Diagnostic Challenge." Cureus, 2023.
- Bozzatello P, et al. "The role of trauma in early onset borderline personality disorder: a biopsychosocial perspective." Frontiers in Psychiatry, 2021.
- Pagura J, et al. "Comorbidity of borderline personality disorder and posttraumatic stress disorder in the U.S. population." Journal of Psychiatric Research, 44(16):1190–1198, 2010.
- Stoffers-Winterling JM, et al. "Psychological therapies for people with borderline personality disorder." Cochrane Database of Systematic Reviews, 2022.