In 2006, the American Journal of Psychiatry reported that the percentage of American adults with major depression in 1991 was 3.33 percent, but by 2001, the percentage had more than doubled to 7.06 percent.

The serotonin-deficiency theory of depression was so successfully marketed that it was news to many Americans when Newsweek's February 26, 2007 cover story, "Men and Depression," mentioned that scientists now reject the theory that depression is caused by low levels of neurotransmitters such as serotonin.

Thomas Insel, director of the National Institute of Mental Health, told Newsweek that "a depressed brain is not necessarily underproducing something."

The demise of the serotonin-defi...

In 2006, the American Journal of Psychiatry reported that the percentage of American adults with major depression in 1991 was 3.33 percent, but by 2001, the percentage had more than doubled to 7.06 percent.

The serotonin-deficiency theory of depression was so successfully marketed that it was news to many Americans when Newsweek's February 26, 2007 cover story, "Men and Depression," mentioned that scientists now reject the theory that depression is caused by low levels of neurotransmitters such as serotonin.

Thomas Insel, director of the National Institute of Mental Health, told Newsweek that "a depressed brain is not necessarily underproducing something."

The demise of the serotonin-deficiency theory of depression should not be considered news in 2007 because in 1998 The American Medical Association Essential Guide to Depression was already stating:

"The link between low levels of serotonin and depressive illness is unclear, as some depressed people have too much serotonin."