When Diagnoses Collide: BPD, PMDD, and the Overlapping World of Mental Health

Let’s be honest: the human mind doesn’t come with tidy warning labels. Mental health symptoms are more like a puzzle dumped out on the table—pieces everywhere, some fitting neatly, others overlapping in wild ways. For a lot of us (myself included), life with a diagnosis isn’t just a single page in a medical manual. Sometimes, it feels like reading from two different books at once—like with Borderline Personality Disorder (BPD) and Premenstrual Dysphoric Disorder (PMDD). Today, we’re hoping to bring a little more light, understanding, and even hope into that mix.

What are BPD and PMDD? Let’s start with the basics:

• BPD (Borderline Personality Disorder) isn’t just about “being sensitive.” It’s a pattern of intense emotions, rapid mood changes, struggles with self-image, and relationships that sometimes feel like roller coasters on rocket fuel. About 1.4–2.7% of people in the U.S. will experience BPD at some point in their lives.

• PMDD (Premenstrual Dysphoric Disorder) is not just “bad PMS.” It’s a severe form of premenstrual mood disturbance that impacts about 3–8% of women of reproductive age, often making even daily tasks a challenge for a week or more every month. 

And here’s something important: having more than one diagnosis is pretty common in the mental health world—think of it as having both coffee and tea at your breakfast table. Sometimes, they even bump elbows.

Why Do BPD and PMDD Overlap?

You might wonder: “How did I end up in both of these clubs?” Turns out, science has some clues. Both BPD and PMDD can be linked to things like a history of trauma, genetic sensitivities, and the way our brains handle emotions. They share a core set of symptoms—mood swings, irritability, feeling overwhelmed in relationships and with ourselves. Some research even suggests that a significant portion of people with BPD experience heightened premenstrual symptoms, so it really can be a storm on top of a storm.

My own experience with early trauma set the stage for both emotional ups-and-downs and intense PMDD symptoms. I’ve had weeks where it seems like my heart’s on a merry-go-round and my brain is shouting, “Please get off!” And I’m not alone: a close friend with both BPD and PMDD once described her hormone-fueled bad days as “trying to outrun a flock of geese with firecrackers,” which I think sums it up perfectly

How Does Overlapping Mental Illness Show Up?

It’s not just BPD and PMDD. In the wide world of mental health, overlapping (or “comorbid”) diagnoses are actually the rule, not the exception. Depression and anxiety often dance together. ADHD and mood disorders swap hats. If your “mental health puzzle” feels complex, that’s not a personal failing—it’s a very human twist.

Feeling like your symptoms are too much or too confusing doesn’t make you weak or attention-seeking. It makes you… normal, in a world where brains like to color outside the lines.

Approaching Treatment for BPD + PMDD

Dealing with both diagnoses can feel overwhelming, but treatment absolutely is possible—and hope is real. Here’s what can help:

• Team Approach: Don’t be afraid to “build your squad” of supports: therapist, psychiatrist, general doctor, gynecologist. They should talk to each other and to you.

• Therapy: Dialectical Behavior Therapy (DBT) is often first-line for BPD—think emotional regulation, mindfulness, and building better relationships.

• Hormonal Management: PMDD may respond to hormonal birth control or SSRIs (antidepressants), sometimes just in the second half of your cycle.• Lifestyle Support: Good sleep, regular movement, and tracking your symptoms (apps work!) can help you spot patterns and get ahead of the hardest days.

• Self-Compassion: Some months will be harder than others, and that’s not a failure—it’s just part of how overlap works.

Support Resources

You don’t have to do this alone, and there’s never shame in reaching out for help or community. Here are some starting points:

• National Education Alliance for Borderline Personality Disorder (NEABPD)

• The International Association for Premenstrual Disorders (IAPMD)

• NAMI (National Alliance on Mental Illness)

• Mind UK – helpful for general support, even outside the UK

• Local support groups, crisis lines, or online peer forums—sometimes just knowing someone “gets it” makes all the difference.

Finding Hope in the Messiness

If you live with both BPD and PMDD (or any combination of “alphabet soup diagnoses”), know that you’re not alone and you’re certainly not “too much.” Complicated is common. There’s something deeply hopeful in understanding how your puzzle pieces fit—because understanding is the first step to compassion, and compassion leads to real, meaningful change.