Major depression is responsible for almost 4 percent of the disease burden in the United States. In 2015, around 16 million U.S. adults aged 18 or older reported having had at least one major depressive episode in the previous year.
Although there is a range of treatment options for people with depression, there is no cure and we still have much to learn. Because of this, research into the brain activity associated with depression is paramount.
The precise causes of depression are not always clear, but certain factors are known to play a part: poor sleep, for instance, is a relatively common risk factor.