The difference between Bipolar Disorder and Borderline Personality Disorder

It is amazing how often people get these two psychological conditions confused. They say, ‘They have Bipolar…. or Borderline Personality Disorder… I don’t know, one of them.’

Are they different? – Yes!

Very different?  – Bigtime yes!

Let’s break it down.


Bipolar is about having mania or depression, and there are three types of Bipolar.

1) You can either cycle between mania and depression.

2) You can just have mania, or

3) You can just have depression. So Bipolar is about mood changes.

The manic presentation is pretty obvious to the eye, it is about peculiar behaviour that can look fun, but it’s actually reckless without thought for the consequences or whether the decisions make sense or sits within our value system. I’ve know people to buy multiple pianos when they don’t even play piano, to go on a houseboat and have sex with strangers, and to continue to stack and unstack chairs.

The depression form of Bipolar can be hard to separate from Major Depression Disorder. Often, if a patient improves with Lithium, it means that it is the depression type of Bipolar, as this is a medication that specifically works for Bipolar.

A common myth… the person does not change between the depressive/manic cycles within a day or week. They go for periods of months of depression OR mania before they resolve. It’s a really upsetting, exhausting, and confronting time for families.


BPD is about feeling that your sense of self is not formed. It is about feeling empty like you are rattling around in a tin can. Perhaps something has gone wrong during the developmental stage when we learn ‘who am I, what am I about, what are my values, what is my voice?’

BPD is very tough and sad for the family because of the desperate things people with BPD do to try to feel more secure and grounded in who they are. They often cling on to someone and glorify them because they think ‘If they’re great and I’m with them, then I’m secure, and I’m great’. But when we put anyone on a pedestal, there is only one way to go: down! The BPD person finds fault in their person, they turn against them, they demonize them, and then they feel incredibly let down, demoralised, and insecure. We have two extremes here in their relationships: Push-pull, hot-cold, idolize-demonize, or as Taylor Swift sings ‘I love you, I hate you.’

People with BPD really struggle to cope with their emotions and to ‘emotionally regulate.’ They can turn to desperate measures such as self-harm to get their overwhelming emotions out or to numb themselves.


Well… they start with ‘B’ and they are about going to extremes, but with completely different ingredients of our psychology. One with mood state, the other with how we feel about ourselves and our people (while experiencing a rollercoaster OF BPD emotions).


they are both really tough for all involved. We need to understand these mental health conditions before we can have compassion for those grappling with them. That is the goal of this blog, understanding and compassion.


Dr Kirsten Hunter

Dr Kirsten Hunter is a Clinical Psychologist of 22 years. She works with children, teenagers, adults and couples.

Kirsten has written 6 DIY psychology books (Signposts for Living) and 4 Child Psychology picture books (SQUISH Series).

Kirsten is the mother to 5 beautiful boys. Alongside her husband Jon, she loves scuba diving and getting lost in nature.

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