The mood swings associated with bipolar disorder can have serious effects on a person's social and occupational health. These mood swings can be so pronounced that the individual is unable to earn a livelihood or cope effectively with the activities of daily living.. Because this disease is not uncommon and can have such an impact on the sufferer's life, there's much ongoing research looking into the cause of bipolar disorder.
What have we learned so far from bipolar disease research?
The definitive cause of bipolar disorder is still unknown. There have been numerous theories put forth as to possible etiologies ranging from biochemical imbalances to environmental exposures during childhood. There's substantial evidence that there may be a genetic component to this disorder since studies done with twins have shown that when one twin has the disorder, there's an 80% chance the other twin will develop it. This is a strong correlation, although environment may still play a significant role since 20% of the twins never develop the disorder.
The general thought is that bipolar disorder is caused by an imbalance of certain important brain chemicals which act as neurotransmitters in the brain. These are the chemicals that send messages between brain cells. These neurotransmitters include norepinephrine, dopamine, and serotonin. It may be that due to genetics an individual produces to much or too little of one or more of these neurotransmitters causing the symptoms of bipolar disorder to develop at some point in his or her life. This is currently thought to be the most likely cause of this disorder.
Other studies have looked at the role stress might play in the development of bipolar disorder. Studies have shown that the onset of bipolar symptoms is more common after a stressful event such as a death in the family, birth of a child, chronic illness or a major life change. There's no doubt that stress can play a role in triggering an exacerbation of bipolar disorder, although this may not be the primary cause of the disease. It's possible that a stressful event may aggravate a biochemical brain imbalance which is already present, resulting in the emergence of bipolar symptoms.
As with most diseases, the cause of bipolar disorder is likely multi factorial with genetics giving a person a susceptibility to the disease and the environment further determining whether symptoms actually develop. This would explain the important role that stress plays in aggravating symptoms in an already susceptible individual. It will be interesting to see what future studies show regarding the exact roles that genetics and the environment play in the cause of bipolar disorder.
