Scratch a comedian, they say, and you'll find a sad soul.

For out comedy writer Chris Kelly, tragedy came in the form of his mother's death from cancer in 2009. In the last year of her life, Kelly moved back home to Sacramento to care for her and help out his family.

Amazingly he transformed this gut-wrenching personal saga into Other People, an authentically moving comedy-drama opening today in selected theaters.

Kelly wrote and directed the film, which sees SNL veteran Molly Shannon as Joanne, a vivacious and funny wife, mother and schoolteacher fighting the ravages and humiliations of terminal cancer—and coming to grips with the fact that she probably won't win.

Standing in for Kelly is Jesse Plemons, best known for ABC's Friday Night Lights. As "David," Plemons grapples with losing his mother while facing a stalled career as a comedian, a failed relationship back in New York, and the ennui that coming back home as an adult can bring.

Other People is not always easy to watch—there a moments I was overcome with emotion—but Kelly also captures how the banalities of life continue even in the face of unfathomable grief and pain.

"Thanks for that," he jokes in an interview with NewNowNext. "I went into this determined not to just make it about her illness. In the movie you don't see Joanne in the hospital all the time. I wanted to convey the progression of her decline, but keep it subtle."

"I wanted to capture this other part of illness people experience but that isn't talked about a lot," he adds. "There are a lot of laughs in the movie."

There are, actually.

Kelly's dialog is so natural, you can forget the specter of death is only a few frames away. And the cast—which also includes John Early, Bradley Whitford, Maude Apatow and June Squibb— commit fully.

One of the film's funniest moments involves Justin, a flamboyant gay tween played by J.J. Totah, who represents everything David isn't.

"Justin was based on a real person," reveals Kelly. "He was the younger brother of a friend and he had more confidence at age 12 than I will till the day I die. I was out when I went back home, but I wasn't confident in myself. We should all be like that kid."

There's even humor in the sex scene between Plemons and Silicon Valley's Zach Woods, who plays his ex.

"We approached that scene like we did the whole movie—not a lot of pomp and circumstance, no melodrama," says Kelly. "The sex scene is very matter of fact."

And while it's definitely universal, Other People also explores themes that particularly resonate with queer filmgoers—like forgiving our parents for not handling our coming out like pros. In the film, David faces off with his father (Whitford), who can't even step foot into David's boyfriend's apartment.

So how autobiographical is the film?

"The bones of it are true," says Kelly. "I lived in New York at the start of my career, and then moved home to help out with my mom. That's all true. But I wasn't trying to re-create what happened moment by moment. It's autobiographical, I'll say—it's authentic even if its not literally true."

This fall, he begins his first season as co-head writer on Saturday Night Live, alongside writing partner Sarah Schneider. Has the experience of losing his mother colored his comedy?

"It's given me me more empathy," he muses. "It dusted off the edges of my writing. I'm probably a little less sharp, a little less mean. I mean, I'm still mean, but I might think about what I'm actually saying about someone rather than just going in for the kill."