How many criteria do you need for a BPD diagnosis?

Five. Under the DSM-5 (Section II), borderline personality disorder is defined by the presence of at least five of nine symptoms. A clinician also looks at how long the pattern has lasted, how much it affects your life, and what else might explain it.

What is the McLean screening test for BPD?

The McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD) is a 10-item self-report questionnaire published by Mary Zanarini and colleagues in 2003. In its original study of 200 people with treatment histories, a score of 7 or more correctly identified 81% of people who had BPD and correctly cleared 85% of people who did not. It is a screen, which means a high score is a reason to ask for an assessment, not a diagnosis.

Is There a Test for BPD? What Diagnoses It, and What Online Quizzes Can Tell You

Q: Is there a blood test for BPD?

No. Borderline personality disorder is diagnosed by a mental health professional through a clinical assessment, not a blood test or a scan. The US National Institute of Mental Health says diagnosis is based on a thorough discussion of symptoms and personal and family history, and that a medical exam can rule out other possible causes. Research on biological markers such as EEG has so far found poor consistency between studies.

Q: How is BPD diagnosed in the UK?

Usually through your GP, who refers you to the community mental health team. NICE guideline CG78 says community mental health services should be responsible for the routine assessment of borderline personality disorder, and the NHS says the assessment will probably be carried out by a specialist in personality disorders, usually a psychologist or psychiatrist. Under 18s are referred to CAMHS.

Q: Are online BPD tests like IDRlabs accurate?

They can tell you whether your answers resemble the pattern a screening tool looks for, and nothing more. IDRlabs' own page says its 20-question test is for screening only and that a diagnosis can only be made by a licensed mental health professional. No online quiz can weigh how long something has lasted, rule out other conditions, or diagnose anyone.

Q: Are there 4 types of BPD?

Not as a diagnosis. The four types, usually given as discouraged, impulsive, petulant and self-destructive, come from Theodore Millon's model of personality. They are a theory, and authors who used them in a 2022 case report wrote that research on BPD subtypes is sparse and awaits further validation. A quiz that sorts you into one of the four is sorting you into a theory.

No. There is no blood test or brain scan for BPD: it is diagnosed by a mental health professional in a clinical assessment, and in the UK, NICE guideline CG78 says that assessment belongs with community mental health services. The closest thing to a test is a screening questionnaire. The best studied, the McLean Screening Instrument (MSI-BPD), correctly picked out 81% of people with BPD in its original 2003 study, and it still cannot diagnose you.

I have BPD, and before I had the words for it I searched for a test too. So this is the page I wanted then: what a test can and cannot do, which ones are real, and what actually gets you a diagnosis. I am not a clinician, so every fact below is linked to where it came from.

Is there a blood test for BPD?

No. There is no blood test, scan or lab result that diagnoses borderline personality disorder (also known as emotionally unstable personality disorder, or EUPD).

The US National Institute of Mental Health puts it plainly: a licensed mental health professional can diagnose it "based on a thorough discussion of symptoms and personal and family history". It adds that a medical exam can further rule out other possible causes. So you might have blood taken during the process, but that is to check for something else, not to find BPD.

Researchers are looking for biological markers. A 2020 review of EEG (brain-wave) studies in EUPD found a number of candidate markers but "poor consistency between studies". A 2026 review of assessment in teenagers discussed possible digital markers from phones and wearables, and its authors were clear that this was a proposed direction, not a validated diagnostic framework. None of it is something your GP can order.

If you landed here because a blood test result came back marked "borderline", that is a different use of the word entirely, and the person who ordered the test is the one to ask.

How is BPD diagnosed in the UK?

Through a conversation, or several, with a specialist. The route is GP, then community mental health team.

NICE guideline CG78, at 1.2.1.1, tells GPs when to refer:

If a person presents in primary care who has repeatedly self-harmed or shown persistent risk-taking behaviour or marked emotional instability, consider referring them to community mental health services for assessment for borderline personality disorder. If the person is younger than 18 years, refer them to CAMHS for assessment.

At 1.3.1.1 it says community mental health services "should be responsible for the routine assessment, treatment and management of people with borderline personality disorder". And at 1.3.1.2 it lists what that assessment should fully cover:

psychosocial and occupational functioning, coping strategies, strengths and vulnerabilities
comorbid mental disorders and social problems
the need for psychological treatment, social care and support, and occupational rehabilitation or development
the needs of any dependent children

The NHS says the assessment "will probably be carried out by a specialist in personality disorders, usually a psychologist or psychiatrist", and will involve being asked about your thoughts and feelings, what you are good at and where you have difficulty, and how you are managing day to day.

The criteria being weighed are the DSM-5 ones: borderline personality disorder is defined by at least five of nine symptoms. That is the count every legitimate checklist, including mine, is built around.

The full route, what to say to your GP, and what you are entitled to afterwards, is in how to get assessed for BPD on the NHS.

What test do psychiatrists use to diagnose BPD?

The diagnosis itself is a clinical judgement. In research, the reference standard that questionnaires are checked against is a structured or semi-structured clinical interview, a long, scripted set of questions asked by a trained interviewer. The studies below used three of them: the DIPD-IV, the SCID-II and the SIDP-IV.

What you will not get is a single score that decides it. That is the honest answer to "what test do they use": a trained person, asking structured questions, over time.

What is the McLean Screening Instrument (MSI-BPD)?

It is the best-known validated self-report screen for BPD. Mary Zanarini and colleagues at McLean Hospital published it in 2003.

	Original MSI-BPD study (2003)
Items	10, answered by the person themselves
Sample	200 people aged 18 to 59 with treatment histories
Checked against	A blind diagnostic interview (DIPD-IV)
Best cut-off	7 or more of the 10 items
Sensitivity	0.81 (correctly identified cases)
Specificity	0.85 (correctly identified non-cases)
Aged 25 or under (63 people)	Sensitivity 0.90, specificity 0.93

What those numbers mean in plain English: in that study, about one in five people who did have BPD scored under the cut-off, and about 15 in 100 who did not have it scored over. And 139 of the 200 (69.5%) had BPD, which is nothing like the mix of people who take a quiz online at 2am.

The cut-off does not travel perfectly, either. A 2020 study of the French version in 84 adolescent patients and 85 matched controls found the original cut-off of 7 had high specificity (0.95) but low sensitivity (0.63), and that 5 or more worked better in that group. A 2015 study of the Dutch version also found its best cut-off at 5.

That is what a screen is: a good first filter, tuned on particular groups of people. It is not a verdict.

Are online BPD tests like IDRlabs accurate?

Here is what IDRlabs says about its own borderline test, on its own page:

It is 20 questions, and it says it is based on DSM-5 criteria and the McLean screening instrument, while not being affiliated with those researchers.
It says it is "to be used exclusively for screening purposes", and that "a mental health diagnosis can only be made by a psychiatrist or other mental health professional".
On validity, it points to the published evidence for "the research and tools used to create the present test", including the McLean instrument. I could not find, on that page, a published validation study of its own 20-question version.

So treat it as what it says it is. Any online quiz can tell you whether your answers look like the pattern a screen looks for. It cannot:

tell how long something has been true, which matters, because a terrible year is not a personality pattern
rule out the things that overlap, such as complex PTSD, bipolar disorder or ADHD
see what a crisis looks like from the outside, or what it costs you
diagnose you, or rule BPD out

And "does my partner have BPD" quizzes are a step further from evidence. The MSI-BPD was validated as a questionnaire filled in by the person themselves. Answering it about someone else is guessing at their inside from your outside, and it says more about the relationship than about either of you.

Are there 4 types of BPD?

Not as a diagnosis. The "4 types of BPD" come from Theodore Millon's model of personality, usually listed as discouraged, impulsive, petulant and self-destructive. A 2022 case report that used the "discouraged" subtype summarised them that way, and its authors also wrote that research on BPD subtypes and their treatment "have been sparse and await further validation".

The definition clinicians assess against is the five-of-nine count. So a "4 types of BPD test" is sorting you into a theory. It can be interesting. It is not information about whether you have the condition.

The same goes for "quiet BPD". It is the name people use for the presentation where everything is turned inward, the disappearing and the private self-hatred, and it is a useful word for being recognised. It is a description, not a separate diagnosis.

Where does my quiet BPD self-check fit?

I built the quiet BPD self-check because most checklists only describe the loud version, and people like me read them and decide it is not us. It walks through the nine signs, each shown the way it is usually described and the way it looks turned inward.

It is a reflection tool, not a test. There is deliberately no score at the end. What it gives you is a printable page in your own words to take to your GP, which is the part most people find hardest. What you enter stays on your own device.

I scored high on a BPD test. What now?

Do not treat it as a diagnosis, in either direction. A high score is a reason to ask; a low one is not an all-clear if your life says otherwise.
Book a GP appointment and lead with the pattern, not the quiz. NICE 1.2.1.1 above is the line to take in.
Keep a record while you wait. A free DBT diary card turns "I feel awful" into weeks of evidence of a pattern, which is what an assessment is actually looking for.
If you are in crisis right now, a quiz is not the next step. The numbers are at the bottom of this page.

And if it does turn out to be BPD: it is treatable, and a diagnosis is the key to the therapies that work.

Sources

National Institute for Health and Care Excellence. Borderline personality disorder: recognition and management (CG78), Recommendations 1.2.1.1, 1.3.1.1, 1.3.1.2. 2009, updated 2024.
NHS. Borderline personality disorder: Diagnosis. nhs.uk, last reviewed 4 November 2022.
National Institute of Mental Health. Borderline Personality Disorder (publication). nimh.nih.gov.
Zanarini MC, Vujanovic AA, Parachini EA, et al. A screening measure for BPD: the McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD). Journal of Personality Disorders, 2003;17(6):568-73. PMID 14744082.
Mirkovic B, Speranza M, Cailhol L, et al. Validation of the French version of the MSI-BPD in an adolescent sample. BMC Psychiatry, 2020;20(1):222. PMID 32398037.
André JA, Verschuere B, Lobbestael J. Diagnostic value of the Dutch version of the MSI-BPD. Journal of Personality Disorders, 2015;29(1):71-8. PMID 24932872.
Hines A, Kushner ML, Stumpp N, et al. Different routes to the same destination? Comparing DSM-5 Section II- and AMPD-defined borderline personality disorder. Personality Disorders, 2024;15(5):352-360. PMID 39073371.
Boland C, Jalihal V, Organ C, et al. EEG markers in emotionally unstable personality disorder: a possible outcome measure for neurofeedback: a narrative review. Clinical EEG and Neuroscience, 2021;52(4):254-273. PMID 32635758.
Močnik S, Gregorič Kumperščak H. Toward a hybrid assessment framework for adolescent borderline personality disorder: a mini review of personality functioning, digital biomarkers, and AI-supported assessment. Frontiers in Psychiatry, 2026;17:1758535. PMID 42487761.
Duică L, Antonescu E, Totan M, et al. Borderline Personality Disorder "Discouraged Type": A Case Report. Medicina (Kaunas), 2022;58(2):162. PMID 35208485.
Powell T, Parker J, Kitson H, Rogalewski M. "It Was Like the Final Piece in the Puzzle for Me": A Qualitative Study on the Experiences of Autistic Women Initially Diagnosed with Borderline Personality Disorder. Autism in Adulthood, 2024;6(4):428-437. PMID 40018060.
IDRlabs. Borderline Personality Test, idrlabs.com/borderline-personality/test.php.

Read from the published abstracts and guidance on 5 October 2026. If something here is out of date or wrong, tell me.

Nothing here is medical advice, it's lived experience, meant to sit alongside real support, not replace it. If you're struggling, please see the support resources. If you're in crisis in the UK, call Samaritans free on 116 123, or dial 999 in an emergency.