Are you missing these signs of anxiety or depression?

The signs of mental illness aren't always obvious. Subtle changes in mood or behavior are often attributed to aging, just like weaker muscles and fuzzy thinking. "There's a tendency to dismiss it as, 'Well, of course I'm worried, I have heart disease,' or, 'Of course I'm sad, I'm not as relevant as I once was,'" says Dr. Michael Craig Miller, an assistant professor of psychiatry at Harvard Medical School.