The other thing that I've experienced both professionally and personally is that a sound diagnosis can be hard to get because some disorders overlap one another, ie BP and BPD, they have a lot of the same symptoms. I've been diagnosed with BP, BPD, PTSD, clinical depression, all having a lot of the same symptoms.

Now worrying about what exactly is my diagnosis, I've just chalked it up to a mood disorder, takes away the confusion.

Hope that helps