The mood swings cripple a borderline's efforts to live a happy, successful life. The symptoms can be so unpleasant to those interacting with borderlines that feelings of compassion and understanding may be difficult or impossible to feel. Borderlines desperately want to be loved, but their illness makes them at times seem unlovable. 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.