Bipolar disorder is a mental illness is often referred to as “manic-depressive illness” or “manic depression.” People with bipolar disorder experience significant mood changes, sometimes feeling very joyous and up, and other times sad and down. According to the National Institute of Mental Health (NIMH), these mood swings are extreme and can cause loss of sleep, high energy levels, the inability to think clearly. Unfortunately, doctors still have not isolated the causes of bipolar disorder.

It runs in the family

Researchers have discovered that bipolar disorder often runs in families, leading them to hypothesize that the cause is genetic? However, according to NIMH, just because a family member has bipolar disorder, other family members will not necessarily have it as well. The evidence for a genetic link comes from children with a parent or sibling with bipolar disorder are much more likely to contract the illness. Doctors have studied identical twins. The study showed that even if one twin develops the disorder the other twin does not always develop the disorder despite the fact they share all the same genes.

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