Diana misses the mountains.

A recurrent theme in the musical "Next to Normal" is the idea of highs and lows. With a main character suffering from bipolar disorder, the show offers a glimpse of what it's like to battle an illness that can take you, as one of its most powerful songs intones, from "all the manic, magic days" to the "dark, depressing nights."

We live in enlightened times when it comes to mental illness (compared to past centuries, at least), with prescription drugs the most common treatment option. ("Valium is my favorite color," goes one of the show's catch phrases.)

But for Diana, a mother and wife whose illness has frayed her family ties in this intense and emotional rock opera, there are trade-offs. Her elaborate pharmacological cocktails might blunt the depths of her lows. But they can also take away the exhilaration of her highs.

Is it better to feel nothing? Or too much? If the drugs don't seem to work, what next?

"Next to Normal" electrified Broadway when it opened in 2009. This show had to be anything but normal, of course.

You don't get away with writing a successful musical about a woman who eventually undergoes electroconvulsive therapy without superlative writing, music, directing and acting. All were in abundance in the Broadway production: It's one of the rare musicals (just eight in history) to win a Pulitzer Prize, a testament to the literary credentials of Brian Yorkey's lyrics and book. Tom Kitt's music is fiercely memorable. And Alice Ripley's tour de force Tony Award-winning performance as Diana was so definitive that it left many wondering whether any other actress could make the role her own.

All of which made Melinda Parrett want to play the part even more.

"When it first came out, I said to myself, 'I want to do this,' " she says.

The professional actor gets her chance tonight, making her Fresno debut in the StageWorks Fresno production of "Next to Normal," a local premiere, at the Dan Pessano Theatre at the Clovis North Educational Center. Parrett is one of two members of the show in Actors Equity, the professional acting union; the other is Joel Abels, the company's artistic director.

Director J. Daniel Herring first saw Parrett -- who has a long string of professional productions under her belt, including ones at Sierra Repertory Theatre, Denver Center Theatre and the Utah Shakespeare Festival -- as a visiting guest artist in a performance of "Curtains" a few years ago at the Pacific Conservatory of the Performing Arts in Santa Maria.

When StageWorks Fresno decided to go outside the area and cast an Equity actor for the pivotal role of Diana, Herring immediately thought of Parrett's performance in "Curtains," even though that show's frothy comedy is a long way from the dramatic intensity of "Next to Normal."

"The key to this show is finding the right Diana," Herring says. "I could just tell she had what it takes. I could instantly tell how focused she can be, how completely in the moment."

It's one of the toughest contemporary roles these days for a musical-theater actor to tackle.

"The places you have to go physically, mentally and vocally to make it through the show -- nothing compares," Parrett says.

As the play opens, we watch as Diana's family struggles with her latest breakdown. We trace her relationships with her husband (played by Abels), children (Taylor Abels and Daniel Rodriguez), her daughter's boyfriend (Aaron Bollinger) and her doctors (multiple roles played by Adam Schroeder).