They are terrified of being abandoned, yet are powerless to keep the illness from destroying relationships. This is the borderline experience. Genetic factors are important - borderline tends to run in families. The risk of developing borderline is 6 times higher when a close relative has the disorder. In studies of identical twins, researchers have discovered that many personality traits are genetically determined.
Borderlines commonly suffer from other disorders as well.
PMS, depression, hypothyroidism, vitamin B 12 deficiency, other personality disorders, anxiety, eating disorders, and substance abuse problems are the most common. Intelligence is not affected by the disorder, but the ability to organize and structure time can be severely impaired. There is no association with Schizophrenia. While many borderlines suffered from abuse or neglect in childhood, some developed the disorder from head injuries, epilepsy, or brain infections. Early parental loss and incest are commonly associated with borderline.