Bipolar Disorder: Who’s at Risk?
Does bipolar disorder run in families?
Numerous studies have found that people with bipolar often have at least one close relative with depression or bipolar disorder.
Children who have one parent with the disorder have about a 10%-25% chance of developing the disorder themselves; children with two parents with the disorder have a 10%-50% chance. If a non-identical twin sibling has the disorder, the chance that another sibling will have it is about 10%-25%.
Studies of identical twins have shown that genetics are not the only factor in determining who is at risk for bipolar disorder. Because identical twins share all the same genes, if bipolar disorder were purely hereditary, then all identical twins would share the disorder.
However, it has been found that if one identical twin has bipolar disorder, the chances of the other twin also having bipolar disorder ranges from 40% to 70%. It is important to note that bipolar disorder can show itself in different forms in individuals in the same families.
Scientists believe that bipolar disorder is not likely caused by any one single gene but more likely multiple genes, each contributing only a small amount to the vulnerability, acting together in combination with other environmental factors such as stress, lifestyle habits, and sleep. Scientists are working to identify these genes in the hopes that this will help doctors to better diagnose and treat the disorder.
Can lifestyle habits increase the risk of bipolar disorder?
Lack of sleep increases the risk of having an episode of mania in someone with bipolar disorder. In addition, antidepressants, particularly when taken as the only medication, may also trigger a switch into a manic state.
Excessive use of alcohol or drugs can also trigger bipolar symptoms. Research has shown that about 50% of bipolar sufferers have a substance abuse or alcohol problem. Sufferers often use alcohol or drugs in an effort to reduce unpleasant feelings during low mood periods, or as part of the recklessness and impulsivity associated with manic highs.
Can environmental stress increase the risk of bipolar disorder?
People are sometimes diagnosed with bipolar following a stressful or traumatic event in their lives. These environmental triggers can include seasonal changes, holidays, and major life changes such as starting a new job, losing a job, going to college, family disagreements, marriage, or a death in the family. Stress, in and of itself, does not cause bipolar disorder (much the way pollen doesn't cause seasonal allergies), but in people with the biological vulnerability to bipolar disorder, having effective skills for managing life stresses can be critical to a healthy lifestyle in order to avoid things that can aggravate the illness (such as drugs and alcohol).