BPD or severe depression?

I have been in terrible doubt for years now after the break-up with my exgf. I am still wondering whether she had a severe depression episode or whether she has BPD. How do you know the difference?

BPD and depression have different cognitive symptoms, that might be the easiest way to differentiate the two.

For example, someone with depression + no BPD/BPD traits probably won't display the same black and white thinking or have a lack of object constancy (not the child psychology type, the "forgetting" that people continue to be consistent when they're out of your sight type), and they probably won't cycle between idealizing and devaluing someone like people have a tendency to do if they have BPD.

But since depression can manifest itself in completely different ways in people, it can be hard to tell. Some people with depression are the "classic" type, while others get apathetic and don't really feel sad, but just joyless and lethargic.

But we don't know your ex-gf, and none of us can diagnose her anyway.

As Czmum said,

Bpd and depression have different cognitive symptoms.
She might have BPD. She might not.

Anyway, it's not your business anymore. You should just move on from that relationship and stop worrying about this.

Did she have a diagnosis or are you trying to determine something on your own? Because you wont be able to tell on your own. A lot of what the person is going through is happening inside themselves, or privately, not fully apparent to other people, and they will be trying to appear as normal as they can. So, imo, the full symptoms wouldn't have been observed by you. Whatever the case she was struggling and that's enough.

Depression seems more "physical" to me. It is not just reacting negatively to life events. Along with having little or no motivation, there's a general feeling of being run down and tired. The sense of exhaustion that comes with depression permeates my entire body. It isn't just a mental thing. I could win the lottery tomorrow and it wouldn't necessarily put a dent in my depression. It is a lot like having a flu where you feel miserable no matter what is going on in your life and what you're doing.

Depression associated with BPD usually responds dramatically to external events. Though extreme, it is very situational. Something positive can happen and it will be instantly gone. Normal clinical depression does not simply go away like that. You feel sick like you have a flu or something. Your whole body is weighted down. It also tends to drag on and on and on and only clears up gradually.

I would agree with the other user in that I don't think it's really of much use to you to continue thinking about this, but I'll answer your question anyways. BPD and depression are two different psychiatric conditions, though they can sometimes overlap. Looking at them separately, there are many differences.

For one, BPD is a personality disorder, while depression is a mood disorder. This means that BPD develops as someone grows up and is most likely a result of both genetics and environmental events that occur throughout childhood and adolescence. Depression on the other hand can be developed by anyone at any time, and symptoms only have to be present for a minimum of 2 weeks to be diagnosed. So, did your girlfriend have an extensive history of behavioural and emotional problems? Does anyone in her family have similar problems? Or did it just appear to be an episode?

The symptoms are also different. BPD is often characterized by an unstable sense of self, feelings of emptiness, self-destructive behaviour, frequent and intense mood swings, unstable relationships and suicidal ideation. Again, as this is a personality disorder these symptoms would also have been affecting your girlfriend for quite some time. Depression on the other hand is often characterized by a consistently low mood, loss of enjoyment in things, feelings of hopelessness, and changes in appetite.

It's up to you which one sounds more like your ex-girlfriend.