Demi Lovato performed Sunday at the Wolf Trap in Vienna. (Kyle Gustafson/FOR THE WASHINGTON POST)

Demi Lovato’s bio would read like a teen celeb version of the Book of Job. She’s confessed to Cosmopolitan that she’s bipolar, gone on Ryan Seacrest’s radio show to admit being a cutter, told People magazine she lost her Disney TV show because it “wasn’t healthy for my recovery” from bulimia and announced on Twitter that she’d been dumped by Joe Jonas.

Her public travails have only left Lovato, just 19 years old, easier to shriek for. Sunday at Wolf Trap, it had to be more than the music that had an amphitheater full of mostly adolescent girls shrieking nearly nonstop for 90 minutes. It just had to be.

Rick Elkins of Woodbridge took his teen daughter, Barbara, to her third Lovato show, loaded with posters with flashing lights and slogans such as “Lovatic 4 Life!” Elkins said the way Lovato has confronted her challenges helped make her a hero in his household. “This is a person my daughter looks up to as a role model,” Elkins said. “There’s so many scumbags out there. And, yes, I like her.”

Lovato, whose show-biz career started on the kiddie dinosaur show “Barney and Friends” when she was 7, does have some obvious star qualities. She oozed genuine sweetness, constantly complimenting her band and thanking the fans for their ovations and for sticking by her. And, although decked out in a full pantsuit and black pleather jacket and running and hopping and flipping her long and new bottle-blond locks all night, she didn’t appear to sweat at all.

And she knows her audience. Before “Fix a Heart,” Lovato warned the masses that summer means they’re going to get dumped by their seasonal romance partners. “I’ve gotten through it, and so can you guys,” she said to screams. The tune, alas, had her wailing, “You never really can fix a heart.” She got more howls when she announced: “It’s not a school day tomorrow! No homework! That’s awesome!”

Demi Lovato performed Sunday at the Wolf Trap in Vienna. (Kyle Gustafson/FOR THE WASHINGTON POST)

As for the music, most of Lovato’s set was taken up by processed pop-rock, over which she sang PG-13 lyrics — “Come on with me and we’ll stay up all night long!” from “All Night Long” — in a mid-rangy, competent voice. Nearly every song would have fit just fine on a Disney or Nickelodeon sitcom soundtrack. The artistic high points came with “My Love Is Like a Star,” a light blues number that even fans of, say, Bonnie Raitt, could accept, and “Got Dynamite,” a guitar rocker worthy of Pat Benatar’s canon.

The show peaked with “Skyscraper,” a smash ballad from last year. If melodrama were an Olympic sport, this tune about getting dumped by a really cruel dude could bring home the gold for Lovato. All the fans sang along as if her pain were their pain, and they tried to get their voices to break just like the girl who wasn’t good enough for Joe Jonas.

McKenna is a freelance writer.