It's true that HIPAA protects you but really only at the doctor's office. A law firm can get the information if it "has to do with the case." And then use it. If they are trying to prove that you are "unfit" to take custody away, they would definately do that.

It's a reason why I don't want my ex knowing that I am actually diagnosed with bipolar. Even though he already has full custody of my son, I could easily see him using it against me later if for some reason he stopped letting me have visitation and I had to fight for my rights. But, who knows, I guess lawyers can dig it up.