Possible Causes of Bipolar Disorder
The cause of BPAD is uncertain, but we know more today than we did a decade ago.
Three brain chemicals — norepinephrine, serotonin, and dopamine — are involved in psychiatric disorders. Norepinephrine and serotonin are linked to mood disorders, such as depression and BPAD. Dopamine, is more closely linked to psychotic disorders, such as schizophrenia. However, since these disorders have a number of symptoms in common, all three chemicals are likely involved in different phases of BPAD.
Many studies have shown that BPAD runs in families, so relatives of persons diagnosed with BPAD or depression are more likely to have the disorder than the general public.
The onset of BPAD is often “triggered” by a significant life stressor (i.e., death of a family member, leaving home for the first time, starting college or a new job, etc.). These stressors do not cause BPAD, but can trigger the disorder to become active. “Trigger events” can also cause a person with BPAD to experience a relapse (episode of depression, hypomania, or mania).