Malone reprising lead role in hard-hitting show at San Diego Musical Theatre

In a career that has stretched from San Diego to off-Broadway, no role has stetted Bets Malone quite so much as that of Diana Goodman in “Next to Normal.”

“I said last night, ‘This show gives me a headache,’ ” Malone noted of the previous evening’s rehearsal for the San Diego Musical Theatre production. “And then I know I’m doing it right.”

This is actually Malone’s second time in the lead role of the Tony- and Pulitzer Prize-winning rock musical, which chronicles a suburban mom’s struggles with bipolar disease and the fallout for her family.

The first go-round was last year at the L.A.-area La Mirada Theatre, in a production directed by Nick DeGruccio, who is also staging the SDMT show.

Over the years, Malone — a skilled and seasoned singer-actor who grew up in Vista — has become known mostly for her work in such lighter musicals as “The Marvelous Wonderettes” (which took her to New York) and the Old Globe holiday favorite “Dr. Seuss’ How the Grinch Stole Christmas!,” among many others.

But for a long time she had been wanting to take on edgier roles. Malone says DeGruccio himself still recounts how he initially told the actress that “it’s not your show,” after she expressed interest in “Next to Normal.”

Malone proved him wrong, digging deep to find elements of Diana within herself.

The character’s challenges are of a kind Malone has seen agonizingly up-close in her own life. She and her husband, Steve Glaudini (now artistic director of Moonlight Stage Productions), were close friends of the actor John Bisom, and both of them worked on numerous shows with him.

Bisom, who fought a fierce battle with depression, took his own life in 2012; Malone calls it “probably the worst thing that’s happened in (our) lives.”

Even now, when she rehearses or performs “Light” — one of the most poignant “Next to Normal” numbers — “his face just splashes through my head,” Malone says of Bisom. “His partner came and saw us do (the show) at La Mirada, and it was a very emotional moment.”

The SDMT production reunites Malone with Robert J. Townsend, who again plays the role of Dan, Diana’s husband. He also played the murderous title character in Moonlight’s “Sweeney Todd” in 2012, opposite Malone’s Mrs. Lovett. And later this year they’ll be matched as Mama and Papa Who in “Grinch” at the Globe.

Malone can’t help but chuckle at that unlikely hat trick: As she jokes, “No two people should play those same six roles!”