Nurse Jackie / United States of Tara

Showtime's sophomore series share many of the same strengths and, increasingly, similar flaws.

Showtime has won considerable acclaim for these two sophomore series, which share many of the same strengths and, increasingly, similar flaws. Both shows feature compelling female leads in showcase roles, but in each case the complementary ensemble isn’t quite so compelling. Calling them “comedies,” moreover, is really a misnomer, since they function more like half-hour dramas, with an occasional laugh thrown in. “Nurse Jackie” and “United States of Tara” still make for a formidable and watchable-enough block, but while each has flirted with greatness, neither consistently achieves it.

Based on its promising first season, “Tara’s” second go-round is the bigger disappointment, due largely to a story arc that blunts some of the charms associated with Toni Collette’s title character, who struggles with dissociative identity disorder, or multiple personalities.

After acting to address the problem at the end of season one (and stop here if you’re planning to catch up on DVD), Tara has seemingly stopped experiencing such episodes. When they resume, she’s reluctant to inform her husband (John Corbett) about these new bouts and her nocturnal carousing, potentially disrupting their relationship: Other personalities he can deal with; being misled is another thing.

Yet while most of the first season was filtered through Tara and her “alters,” the second spends roughly equal amounts of time with each of the regulars, including her son (Keir Gilchrist), a teenager grappling with his sexuality; daughter (Brie Larson), who meets an intriguing woman (Viola Davis) through her dreary job at a collections agency; and relationship-challenged sister (Rosemarie DeWitt).

“Tara” also acquires some new supporting players, but the show feels more disconnected in scattering to pursue these various plots. In addition, the evolving interaction between Tara and her alters as she becomes “co-conscious” with them feels like little more than split-screen gimmickry.

Six episodes were previewed, and the producers fortunately saved the best for last, but until then it’s something of a letdown. Nevertheless, Collette’s performance — by turns sexy, vulnerable and baffled, even before she zones out and becomes someone else — is worth the price of admission. You just wish there was more of it.

“Nurse Jackie,” too, has a powerful central presence in Edie Falco as Jackie Peyton, whose big problem this year is the budding friendship between her husband (Dominic Fumusa) and first-season boyfriend, Kevin (Paul Schulze), whose behavior — insinuating himself into the couple’s life — makes her understandably uneasy.

The show’s anti-heroine faces complications at work, too. Jackie must hide her pill-popping habit from a suspicious colleague, while she remains at odds with the pompous, self-obsessed Dr. Cooper (Peter Facinelli), who has been designated the hospital’s public face in a cheesy marketing campaign titled, “If Looks Could Cure.”

Yet while Jackie remains a fascinating conundrum — a woman who takes noble stands and cuts corners on behalf of her patients, while hanging by a tenuous thread in her personal life — the brooding tone can become stifling. It’s cathartic, in fact, when Jackie finally blows up in a later episode, telling her husband he has “no idea what it feels like to be me.”

Other members of the hospital staff have their own struggles, and there are again plenty of topnotch guest stars, such as Julia Ormond and Harvey Fierstein. Still, their travails don’t get much beyond the sleeping-around-at-work complications found on “Grey’s Anatomy.”

With both shows, Showtime has wisely hitched its wagon to pairing big-name talent with promotable concepts — the kind sure to garner attention from critics and award voters. And while HBO famously claimed to be “not TV,” Showtime now shrewdly bills itself as “TV. At its best.”

“Pretty Good TV” doesn’t have quite the same ring to it, but for “Jackie” and “Tara,” it’s an accurate diagnosis.

Nurse Jackie / United States of Tara

Showtime,Mon. March 22, 10 p.m.

  • Production: <B>Nurse Jackie:</B> Filmed in New York by Lionsgate and Showtime. Executive producers, Linda Wallem, Liz Brixius, Richie Jackson, Christine Zander, Mark Hudis, Caryn Mandabach; co-executive producers, Evan Dunsky, Rick Cleveland, Paul Feig; producer, Bari Halle Cannon; director, Feig; writers, Brixius, Wallem. <B>United States of Tara</B> Filmed in Los Angeles by DreamWorks Television. Executive producers, Steven Spielberg, Justin Falvey, Darryl Frank, Diablo Cody, Jill Soloway, Craig Zisk; co-executive producers, Dave Finkel, Brett Baer; producer, Dan Kaplow.
  • Crew: <B>Nurse Jackie:</B> Camera, Vanja Cernjul; production designer, Ray Kluga; editor, Gary Levy; music, Wendy Melvoin, Lisa Coleman; casting, Julie Tucker, Ross Meyerson. RUNNING TIME: 30 MIN. <B>United States of Tara</B> Camera, M. David Mullen; production designer, Cabot McMullen; editor, William Turro; music, Craig Wedren; casting, Cami Patton, Jennifer Lare. RUNNING TIME: 30 MIN.
  • Cast: <B>Nurse Jackie </B> Nurse Jackie Peyton - Edie Falco Dr. Eleanor O'Hara - Eve Best Zoey Barkow - Merritt Wever Eddie Walzer - Paul Schulze Kevin Peyton - Dominic Fumusa Mrs. Gloria Akalitus - Anna Deavere Smith Dr. Fitch Cooper ("Coop") - Peter Facinelli <B>United States of Tara</B> Tara, etc. - Toni Collette Max - John Corbett Charmaine - Rosemarie DeWitt Marshall - Keir Gilchrist Kate - Brie Larson With: Viola Davis, Patton Oswalt, Joey Lauren Adams.
  • Music By: