The 2010 Pulitzer Prize-winning musical, “Next to Normal” explores the devastating impact of mental illness on individuals, their families and loved ones. In its second Triangle staging this season, the piece still packs an emotional wallop, especially in the expert hands of Deep Dish Theater Company.

The central figure is Diana, whose bi-polar diagnosis explains much of the deteriorating relationship she has had with her devoted but long-suffering husband Dan and her emotionally closed-off daughter Natalie, hurt by her mother’s obsessive preference for Natalie’s brother, Gabe. After enduring a range of unsuccessful medical treatments, Diana changes doctors and undergoes hypnosis and ultimately shock therapy, finally forcing her to face her demons and make some life-changing decisions.

The show is designated a rock musical, but the term misleads, as Tom Kitt’s score contains many heartfelt ballads and stirring Broadway-style anthems. Brian Yorkey’s lyrics are clever without being cute, repeatedly gripping in their poignant truths. Thankfully, the lyrics are easily understood here, as the backstage band, under Julie Florin’s sensitive direction, is heard through speakers and never allowed to overpower the singers. Occasional imbalances and dropouts from the singers’ mics are the only distractions.

Deep Dish’s small stage is shrewdly disguised by Rob Hamilton’s design of gauzy, interlocking walls that swivel to create different scenes, revealing characters when lit from behind. Director Paul Frellick keeps the staging simple but nicely varied, the intimate space permitting every subtle facial expression and quietly spoken phrase to register.

Lisa Jolley gives Diana full range, her desperation to understand her predicament moving, her realizations of it heartbreaking. As husband Dan, John Allore is extremely affecting, making Dan’s feelings of helplessness and loss palpable. Abigail Coryell’s Natalie is smartly judged, its hardened surface hiding a frightened, damaged soul.

Wesley Miller’s confident vocals and tender sincerity make Gabe’s special connection to his mother sweetly touching, while Mark Ridenour gives both doctors depths beyond their stereotypical characters. As Natalie’s love-struck boyfriend Henry, Jeffrey Vizcaino sings impressively but plays the character blandly.

If you missed Theater in the Park’s production last fall, Deep Dish’s is equally recommended, its intimacy giving the material even greater force. And don’t forget the tissues and handkerchiefs – you’ll definitely need them.

Dicks: music_theater@lycos.com