Bipolar disorder affects an estimated 30 million people all over the world. It strikes women and men equally, without restriction to ethnic group or class. Age, however, is a factor, and bipolar disorder tends to appear first in young adults.
Wealthy, sophisticated countries are more likely to produce studies and statistics about bipolar disorder than are poorer nations or than societies where illness is regarded as shameful and is kept secret. As a result, a completely accurate world survey of the occurrence of bipolar disorder does not yet exist. But it seems reasonable to hope that with better ways to diagnose bipolar disorder, treatment will become better and more widely available, and statistics will be more reliable.
Cancer and Alzheimer's disease are among illnesses that are less likely to disrupt the patient's life than bipolar disorder. The reason seems to be that bipolar disorder affects many more years of a person's life than do Alzheimer's and cancer.
Diagnoses of bipolar disorder have shadowy boundaries because the symptoms cover a spectrum. In Europe, half of the approximately 2% of the citizens who are bipolar are apt to have bipolar disorder 1, which is more severe than bipolar disorder 2. Of the two bipolar extremes, depression and mania, depression typically is more common, and suicide is a threat. A third category, subthreshold bipolar disorder, has also been called bipolar not otherwise specified (bipolar NOS).
The psychiatrist who diagnosed me used the term bipolar not otherwise specified. I say I am bipolar 2, but I probably shouldn't make that claim; it just seems easier than trying to explain NOS.
Statistically, bipolar disorder is more frequently diagnosed in childhood in the United States, Norway, Spain, Italy, and Turkey than in France, The Netherlands, the British Isles, or Australia. This oddity reminds me that a friend who is an expert in statistics once said that knowledgeable statisticians can prove anything they are asked to prove by designing the questions to get the desired answers. This is not, she stressed, ethical. But it does indicate that we should be skeptical of statistics.
Complicating the international bipolar issue, outlooks for bipolar patients who are diagnosed and treated in different countries can't necessarily be compared accurately, because they may be treated with different medicines or with different doses of identical medicines.
The younger a person is when diagnosed with bipolar disorder, the more likely she or he is to begin receiving treatment at the onset of the disorder. Not surprisingly, people who are not diagnosed and treated early tend to develop more severe symptoms. Early diagnosis is, then, key in treating the disorder most effectively.
Bipolar disorder is still not fully understood. For instance, United States citizens with mood disorders are more likely to marry someone with a mood disorder than those with mood disorders in other countries, but no one has successfully explained this.