In Every Brilliant Thing, actor Isaac Lamb lists the guidelines newspapers follow when reporting on a suicide: never describe the method used, don't assume motivation from recent life events, don't use the word "commit" in reference to the action, never describe an attempt as "successful."

"Suicide is contagious," says Lamb, who plays the one-man show's unnamed character. One suicide can often lead to more suicides in densely populated areas, he explains, citing the Goethe novel The Sorrows of Young Werther. Toward the end of the play, he adds, "There's one thing you should know if you're considering suicide: don't do it."

Every Brilliant Thing is the story of a man and his mother, and how her attempt to kill herself when he was a child shaped the rest of his life. It's why the narrator began crafting a running list of small and large life-affirming pleasures—ice cream and roller coasters when he started the list at the age of seven, sex and meaningful conversations as he entered adulthood.

Though the one-man show is about living in the shadow cast by the attempted suicide of a loved one, it's playful, unconventionally structured and unapologetically sentimental. It's more like group therapy than a traditional play. Audience members are called on stage to play a vet that euthanizes the main character's childhood dog, or our narrator at seven-years-old who can only respond "why?" as his father struggles to explains that his mother tried to kill herself.

Written by Duncan Macmillan, the play premiered at England's Ludlow Fringe Festival in 2013. It started its successful off-Broadway run a year later, and last fall, a film of a New York performance made its way to HBO. In the three years since its premiere, almost all of the productions have been performed by the same actor, British comedian Jonny Donahoe.

Thematically, Every Brilliant Thing doesn't take many risks. Macmillan himself once said of the play, "It's the least cool piece of theater ever, in some ways." Often cloyingly sentimental, Every Brilliant Thing is not for even the mildly cynical, or those who are unwilling to put aside the fact that a list of "brilliant things" is a simplistic response to a complicated issue.

Still, Every Brilliant Thing succeeds thanks to Lamb's everyman affability as well as its communal spirit. More than anything, it's an exercise in empathy. As the play progresses, it becomes as much about our narrator's depression as his mother's. Decades after his mother's attempt at suicide, he's listed hundreds of thousands of brilliant things. But as he reaches middle age, it becomes more and more clear that optimism isn't the same thing as happiness.

Anti-suicide is hardly a radical stance, but Every Brilliant Thing isn't particularly interested in challenging social or artistic conventions. More than just a staging gimmick, the audience interaction is the play's main message. Offering support, Every Brilliant Thing concludes, can be more powerful than all life's brilliant things combined.

SEE IT: Every Brilliant Thing is at Portland Center Stage, 128 NW 11th Ave., pcs.org. 7:30 pm Tuesday-Saturday, 2 pm Saturday-Sunday, noon Thursday, through Nov. 5. No 7:30 pm show on Sunday, Oct. 8.$25-$55.