What We Often Fail To Realize About Depression

There are a few key elements about depression that we've all come to understand. For example, we know it's not about feeling sad every now and then, it can be triggered by things like smoking and too much sitting , and behaviors such as excessive fidgeting and performing tasks more slowly can be unexpected signs you're depressed.

But for everything we know about this mental illness, there's still a big element that we tend to overlook, according to Pulitzer Prize winner, Columbia professor and author Margo Jefferson, who has written candidly about her own experience with depression in her best seller, Negroland.

"What's often not acknowledged about depression is how much anger is in it," Jefferson says.

As Jefferson has experienced firsthand, this anger can be tangled within the "heaviness" that people often associate with depression -- especially when a depressed individual feels as if he or she is under a lot of pressure.

"For me, depression is very much tied to my feeling that so much is being asked of me," Jefferson explains. "I have to 'perform,' rather than necessarily be myself. I have to perform a perfect Margo Jefferson, at an impossibly high level."

This is when the anger comes in.

"A part of me is just saying, 'This isn't fair. I can't do it any longer,'" Jefferson says. "I don't have any practical worldly means by which to say... 'Look, let me be honest: This isn't working.'"

The only alternative that she and people in similar situations may see is to shut down and retreat into themselves.

"I'm stuck with that performance, so the only thing I can do is drop the curtain and say, 'The show's over,'" Jefferson says.

Need help with mental health issues? In the U.S., call 800-662-HELP (4357) for the SAMHSA National Helpline .

Also on HuffPost: Dwayne "The Rock" Johnson opens up about his battle with depression