Bipolar disorder, otherwise known as manic-depressive disorder, is a mental disease that entails sudden mood swings between the manic phase (short-tempered, euphoric and energetic) and the depressed phase (simply depressed). However, this disease is not overly debilitating; Beethoven, the inspired composer, and Churchill, the exceptional Prime Minister of Britain during World War II, were both bipolar. It does tend to make the afflicted miserable, however, as in the case of Vincent Van Gogh.
The biggest chemical symptoms of manic depression are the brain chemicals norpinephrine and serotonin. Norpinephrine, as well as dopamine, are in excess during the manic phase, and serotonin is in excess during the depressive phase. Genes control the brain chemicals, and it was this discovery that led to the search for genes for mental disorders. Science has pondered whether a genetic cause for bipolar disorder exists since genetics became an efficient research tool, and have found several causes; however, the genes vary from family to family and DNA is only part of the disease. It seems doubtful that a gene-based medicine would work for more than a small segment of the population. As Steve Jones says in The Language of Genes, "There have been announcements of the discovery of single genes for manic depression, schizophrenia and alcoholism. All have been withdrawn." (Jones, Steve, The Language of Genes 191).
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