What gives stand-up comedians the confidence to get up on stage? What gives them such an exceptional capacity for comedy? Are they just innately born with an extra funny bone? Or is it something else entirely?

I was watching comedian Bo Burnham’s live stand-up comedy show, Make Happy, on Netflix the other day when these questions first came to mind. During the hour-long video, I enjoyed the first 56 minutes with my friends, laughing so hard that my mouth hurt from grinning so much. However, my expression changed rapidly and dramatically during the final 4 minutes, which I spent staring stone cold at the screen, eyes nearly pooling with tears.

During those final minutes, Bo Burnham’s lighthearted comedic songs take a drastic turn as he steps off-stage and the camera follows him into a dark room, away from the stage, the lights, and the boisterous sounds of the crowd.

“Oh, good, it’s just us” (Make Happy, 56:43-45) he says, as a single desk lamp illuminates him and his piano, with his back turned to the camera. The solemn tune that follows contrasts immensely with the prior performance, and Burnham proceeds to sing a much more earnest song: a song about how, despite his commendable fame, fortune, and success, he isn’t happy; a song about his struggle with depression.

This poignant scene piqued my final question: Why are so many comedians depressed? According to American stand-up comedian Rodney Dangerfield, "Comedy is a camouflage for depression."

Bo Burnham: hilarious and exultant on stage, but upset off stage. Louis C.K.: brilliant comedian, writer, producer, and director who still struggles to smile. Jim Carrey: hysterical on screen, yet depressed in reality. Owen Wilson: Appears in nearly every modern comedic film, yet has openly struggled with depression for years.

Who else does this peculiar mixture of laughter and depression apply to? Ellen DeGeneres, Woody Allen, Larry David, David Letterman, Sarah Silverman, Drew Carey, Robin Williams… and the list goes on.

In fact, so many comedians are depressed that pyschologia.co published an info graphic listing them.

So why are many the people who make us, the audience, so happy, personally so unhappy?

My personal theory is that when we’re sad, we compensate for it by trying to make others’ happy. It’s like a coping mechanism triggered by empathy. There is pain in laughter; there’s sorrow in smiles. If I couldn’t be happy myself, I imagine I would at least want others to be.

Moreover, depression is linked to rumination. Those who are depressed are often thoughtful and meticulous; they see the world through a different lens. Depression can result in repressed creativity, but it can also trigger one’s creativity to spiral in a unique way. Mental illnesses are brilliant, and almost beautiful, in this way. They enable innovative and unusual forms of thinking.

Plenty of historical artists, musicians, and performers suffered from and struggled with mental illnesses. They found a solace in art. Through art, they somehow managed to silence their minds and block everything else out.

Similarly, through comedy, it is my theory that comedians are able to block out whatever sadness may be in their heads. They are able to experience happiness in some form, whether it be first-hand or second-hand joy.

Making others happy—watching them laugh and smile—makes us happy. Smiling is contagious, as are all facial expressions, according to a paper published in the journal Trends in Cognitive Sciences in 2015. When we see the facial expressions of others, the registration of emotion results in sensorimotor simulation. Thus, to some extent, we feel what those around us feel via sensory information perceived by the brain.

Robin Williams once said that, “You’re only given one little spark of madness. You mustn’t lose it.” So who’s to say madness isn’t linked to brilliance? Who’s to say that madness and sadness aren’t synonyms for brilliance?