One in 4 people in the UK will experience a mental health problem each year.
But depression is something we find difficult to talk about.
A TED talk given by writer and comedian Kevin Breel in 2013 is being shared again online.
During his speech Breel speaks of the common misconception that depression is merely feeling sad when something in your life goes wrong. That it is tied to a specific incident.
"Real depression isn't being sad when something in your life goes wrong. Real depression is being sad when everything in your life is going right. That's real depression."
Kevin Breel didn't look depressed. He was captain of the basketball team, he was at every party, he was full of confidence. But in 2011, he sat on the end of his bed with a bottle of pills and contemplated taking his own life.
"Right now, depression is society's deep cut that we're content with putting a bandaid over," he says.
He implores that "depression is okay. If you have depression, you're okay. It is a part of life". And we need to talk about it.
Though, the single sentence that sums up our attitude towards mental health is perhaps this:
If you break your arm, everyone runs over to sign your cast, but if you tell people you're depressed, everyone runs the other way. That's the stigma.