Military working on 'chip' to fight mental illness?

The military is turning up the heat on one of its most common enemies: mental illness.

The Defense Advanced Research Projects Agency (DARPA) is launching a 5-year program to engineer a microchip that could help treat things like anxiety, depression and posttraumatic stress disorder.

The microchip will be implanted in the brain to detect abnormal activity ... and if there is any, it will stimulate the brain to treat it.

The agency plans to identify brain signaling pathways associated with anxiety and depression, then create devices that will "correct" them by encouraging the brain to strengthen other circuits - essentially eliminating disease symptoms.

A DARPA news release says about 100,000 people around the world use brain stimulation devices to manage certain neuropsychiatric disorders - but these new devices will be more advanced.