Causation

http://video.google.com/videosearch?q=bipolar+disorder&hl=en&emb=0&aq=0&oq=bipolar#
LINK TO VID^^

Bipolar I Disorder is a life-long disease and runs in families but has a complex mode of inheritance. Family, twin and adoption studies suggest genetic factors. The concordance rate for monozygotic (identical) twins is 43%; whereas it is only 6% for dizygotic (nonidentical) twins. About half of all patients with Bipolar I Disorder have one parent who also has a mood disorder, usually Major Depressive Disorder. If one parent has Bipolar I Disorder, the child will have a 25% chance of developing a mood disorder (about half of these will have Bipolar I or II Disorder, while the other half will have Major Depressive Disorder). If both parents have Bipolar I Disorder, the child has a 50%-75% chance of developing a mood disorder. First-degree biological relatives of individuals with Bipolar I Disorder have elevated rates of Bipolar I Disorder (4%-24%), Bipolar II Disorder (1%-5%), and Major Depressive Disorder (4%-24%).
The finding that the concordance rate for monozygotic twins isn't 100% suggests that environmental or psychological factors likely play a role in causation. Certain environmental factors (e.g., antidepressant medication, antipsychotic medication, electroconvulsive therapy, stimulants) or certain illnesses (e.g., multiple sclerosis, brain tumor, hyperthyroidism) can trigger mania. Mania can be triggered by giving birth, sleep deprivation, and major stressful life events.

http://www.mentalhealth.com/

Rumors

Most people have false perceptions of exactly what Bipolar disorder is. There are actually two kinds of Bipolar disorder, Bipolar I and Bipolar II. The more severe of the two is Bipolar I where there are reecurrent manic episodes. If Bipolar I remains untreated there is a high 15% suicide rate. When people think of Bipolar disorder they think of someone being extremly happy one second and then being enraged the second. Although there are severe mood swings they are not of this specific characterization. Victims of Bipolar disorder can be extremly depressed and get thoughts of suicide. These specific moods last for maybe a few days all the way up to a few weeks. But their swing in mood can happen from day to day. One day they may want to kill themselves but the next they will feel on top of the world. Usually a manic episode occurs during the severly depressed stage.