Alexander Strain returns to the stage for “Every Brilliant Thing.” The play about suicide “acknowledges that we’ve all been through something like this, that it’s very strange and tragic,” the actor says. (Stan Barouh/Stan Barouh)

In 2014, Alexander Strain walked away from a D.C. theater career boasting a steady procession of juicy roles that led to four Helen Hayes Award nominations. Many an actor would envy such success, but Strain decided he wanted to pursue his dream of a master’s degree in psychology.

In his new day job, Strain works with people struggling with mental illness, suicide, the consequences of sexual assault and disability. He started looking for plays that dealt with these subjects not as examples of unrelieved suffering nor as sentimental stories of redemption, but realistically: as aspects of families who keep going even as they adjust to these challenges.

Strain found just such a play in Duncan Macmillan’s “Every Brilliant Thing,” and with it he returns to the stage, at Olney Theatre Center, for the first time in four years.

Developed with British actor Jonny Donahoe, “Every Brilliant Thing” was a surprise hit at the 2013 Edinburgh Fringe Festival in Scotland, moved to healthy runs in London and New York and was filmed by HBO. It’s a one-person show about suicide with improvisation, audience participation, comedy and a gimmick that involves a list of all the things worth living for.

“It never implies that everything is okay because of the list,” Strain says. “In fact, it implies that to ever believe that a list would be a cure for depression is hopelessly naive. But that naivete sparks much of the humor.”

The list is a way of heightening the show’s central conundrum: Even with all these reasons for embracing life, some people are still suicidal — and making them read your list doesn’t solve the problem. Sometimes they will respond, as the narrator’s mother does, by correcting your spelling.

The piece, Strain says, “acknowledges that we’ve all been through something like this, that it’s very strange and tragic. But you can still find a small window through which the light can come through.”

The audience becomes a part of telling the story. To evoke the narrator’s initial ride to the hospital, for example, Strain explains that he will now become the father and that a selected audience member will be the son.

“Because I’m already onstage and engaging with the audience as they’re coming in,” Strain says, “I can get a feel for who has the energy to help tell the story and who might be reluctant. Sometimes finding the person who’s not performative lends more weight . . . because it sounds more vulnerable.”

Working on “Every Brilliant Thing” with Olney Theatre’s artistic director, Jason Loewith, has eased Strain’s reentry into theater. The one-person cast and minimal props made the rehearsal schedule unusually flexible; Loewith even brought volunteers into rehearsal to play the roles of the audience. The experience has made Strain open to other roles in other productions.

What he doesn’t want to do, though, is get back on the actor’s treadmill of trying to start a new show as soon as the last one ends.

“Now that I’ve got interesting work outside the theater,” Strain says, “I can afford to wait for opportunities that really engage me.”

If you go
Every Brilliant Thing

Olney Theatre Center, 2001 Olney-Sandy Spring Rd. 301-924-3400.

Dates: Through March 25.

Tickets: $47-$74.