Anna Faris stars in “Mom”

In the '50s and early '60s, Barbara Billingsley doted on her family and kept an immaculately clean home as iconic TV mom June Cleaver in "Leave it to Beaver." Over the years, television moms have changed with the times, representing single mothers such as "One Day at a Time's" Ann Romano (Bonnie Franklin), savvy career-driven matriarchs like "The Cosby Show's" Clair Huxtable (Phylicia Rashad) and working-class moms akin to "Roseanne's" titular character (Roseanne Barr).

Anna Faris ("Scary Movie," 2000) and Allison Janney ("The West Wing") represent modern TV mothers in the CBS comedy "Mom," airing Thursday, April 28, on the eye network. As recovering addicts, Bonnie (Janney) and Christy (Faris) aren't exactly Cleaver-esque prime-time moms, but this mother and daughter often rely on each other when the going gets tough.

Created by Chuck Lorre ("The Big Bang Theory"), Eddie Gorodetsky ("Two and a Half Men") and Gemma Baker ("Two and a Half Men"), "Mom" debuted Sept. 23, 2013. Viewers were introduced to newly sober waitress Christy, single mom to teenager Violet (Sadie Calvano, "Melissa & Joey") and young scamp Roscoe (Blake Garrett Rosenthal, "New Girl"). Roscoe's father, Baxter (Matt Jones, "Breaking Bad"), is a lovable slacker. Christy's circle now includes friends Jill (Jaime Pressly, "My Name is Earl") and Wendy (Beth Hall, "Mad Men"). In the beginning, Christy's mother, Bonnie -- also a recovering drug and alcohol addict -- re-entered her life in the hopes of making up for all of the ways she'd wronged her in the past.

Neither woman is perfect, but Bonnie is particularly troubled, and Janney's portrayal of the complex character has earned her two Emmys. When the actress accepted her most recent Emmy for Outstanding Supporting Actress in a Comedy Series in September, she joked about her "deeply flawed" character, but then added: "One serious thing: So many lives are touched by addiction and it is a privilege to work on a show that reminds us that there is hope."

"Mom" has a reputation for tackling so-called "dark" subject matter head on. Right out of the gate, Christy dealt with teen pregnancy when daughter Violet announced she was expecting. In another season 1 storyline, close friend Marjorie (Mimi Kennedy, "Dharma & Greg") was soon diagnosed with cancer. In season 2, Christy's father, Alvin (Kevin Pollak, "A Few Good Men," 1992), passed away. This season has been particularly tough as Christy and her family bid farewell to Jodi (Emily Osment, "Young & Hungry"), a recovering teen addict who overdosed and died.

Jodi's struggle was a heavy subject for a sitcom, but in a February interview with The Hollywood Reporter, Lorre explained why they had to go there.

"Even though we're doing a comedy and our first issue is to cause laughter, from the very beginning we tried to make this show about recovering from alcoholism and drug addiction, and to do that without ever acknowledging the harsh reality of it seemed to be a cheat," he said.

Allison Janney as seen in “Mom”

The hit comedy series even teamed up with the U.S. Surgeon General to raise awareness about the addiction epidemic in February with a CBS Cares public service announcement, which aired after the Feb. 18 episode. According to U.S. Surgeon General Dr. Vivek Murthy, drug overdoses kill more Americans than car crashes, so the PSA encouraged anyone struggling with addiction to contact the Substance Abuse and Mental Health Services Administration National Helpline.

Three seasons in, the show hasn't shied away from the challenges involved in managing and treating addiction, which is at the heart of every episode. So far, audiences don't seem to be put off by the approach. In fact, "Mom" has been a steady performer in the competitive prime-time market since the get-go, and even experienced a huge ratings jump in season 2. While the freshman season averaged more than eight million viewers per episode, the sophomore season drew well over 11. This season's November premiere earned a little more than seven million viewers, but numbers have climbed, and even hit a high point of nearly nine million in December.

With impressive numbers and critical praise for Janney and Faris, it's no surprise CBS has already renewed "Mom" for a fourth season. News of the renewal broke in March, well in advance of the fall scheduling announcements, which should come at the end of May. "Mom" joins the ranks of comedies "The Big Bang Theory" and "2 Broke Girls," which have also been already renewed for next season.

While not every mom is a recovering addict, "Mom" still offers viewers a heartwarming vision of modern-day motherhood as Christy and Bonnie struggle to keep it together with a healthy dose of humor. Catch Faris and Janney's undeniable comedic chemistry in "Mom," airing Thursday, April 28, on CBS.