Have you ever met someone who reminds you of the Winnie the Pooh character, Eeyore?
Maybe he or she is always down in the dumps with a cloud of gloom overhead.
Some doctors say constantly being blue may be more than just a personality type. It could be a disorder — something called dysthymia, a mild, chronic depression that can last for decades. An estimated five percent of people have it.
But most people who do don't know they have it, so they don't seek treatment. That can have consequences for their work, family and social lives. And it may even put them at higher risk of suicide.
Michelle Gerdes suffers from dysthymia and she told Here & Now's Sacha Pfeiffer that it can slowly erode relationships.
"Your spouse never knows who they're going to get, the angry one, the blue one. Over time, people only put up with so much," she said.
This segment aired on August 26, 2011.