There is an explanation for why depression so often manifests itself as feeling stressed out.

CNN: Stress has taken over: How can I turn my mind off?

Anxiety is more than feeling stressed out.

CNN: Study: Anxiety in youth linked to heart attacks later on

Most people who are feeling hugely stressed out are actually depressed.

CNN: Stress has taken over: How can I turn my mind off?

Because studies show that one of the most sensitive questions for detecting depression in someone is simply to ask him or her if they've been feeling very stressed out over the last couple of weeks.

CNN: Stress has taken over: How can I turn my mind off?

And if the stressed-out feeling has been going on for more than a few weeks, it's time to think about treatment.

CNN: Stress has taken over: How can I turn my mind off?

The fact that this last feeling is so common in depression explains why being "stressed out" is such a good marker for major depression.

CNN: Stress has taken over: How can I turn my mind off?

They noticed that college students were, by and large, stressed out, and wanted the film to convey the same feeling.

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