brain

The Army has "separated" more than 22,000 soldiers for "misconduct" since 2009 — often without benefits — after they returned from war with mental health problems or brain injuries.

Where there's pot, there's often an insatiable hunger. Now researchers have a big clue why: Cannabinoids, the drug in marijuana, appear to flip a neural circuit that normally tells us we're full.

New research shows that teenagers' brains aren't fully insulated, so the signals travel slowly when they need to make decisions. Neuroscientist Frances Jensen, who wrote The Teenage Brain, explains.

Black Friday and the whole holiday season are designed to tap into a very ancient part of our brains. What happens to our brain when we shop during the holidays?

During sleep, the brain locks in existing memories and can even form new ones. Scientists say they are starting to understand how that happens. A midnight snack may interfere.