In developed countries such as the United States, four of the leading ten causes of disability are mental disorders. As Figure 1 shows, these four are unipolar major depression, schizophrenia, manic depressive illness, and obsessive compulsive disorder. Also on this list, however, are alcohol use, dementia, stroke, and drug use. When one adds these conditions to the four mental disorders that I mentioned, eight of the ten leading causes of disability are seen to be brain and behavioral disorders. In the United States, the leading cause of disability is unipolar major depression, a serious disorder that affects 5 percent of Americans at some point in their lives.
Depression often begins early in life, and reoccurrences throughout life are the rule.
While the popular press recently has made much about the widespread use of antidepressants in the U.S., we should not be misled into thinking that the extent of use is evidence that all cases of major depression are identified accurately and treated appropriately. Indeed, all available data tell us otherwise. Despite remarkable strides in developing treatments for depression, which compare favorably with treatments for almost any other chronic affliction of human kind, we are still unable to achieve full remissions or prevent recurrences in many sufferers. Also, the age of typical first onset of major depression explains why mental disorders contribute so much to the burden of disability in the United States and worldwide. With schizophrenia and other severe disorders, we also have made remarkable progress in the palliation of symptoms.