Anna Faris and Allison Janney in a scene from "Mom"

TV moms have evolved over the years. While early TV mothers reflected the ideals of the day with perfectly coiffed hair and scrumptious looking pot roasts, today's TV moms are a more diverse bunch. A sitcom that takes a look at how complicated maternal relationships can be is finally bidding farewell to prime time, and it will surely be a tearful send-off for fans.

Allison Janney ("The West Wing") stars as Bonnie Plunkett, a recovering addict who relies on her close-knit group of friends in her quest to stay sober in the series finale of "Mom," airing Thursday, May 13, on CBS. This season, Bonnie is struggling to deal with an empty nest now that her adult daughter, Christy (Anna Faris, "Scary Movie," 2000), has moved to Washington to go to law school.

When the show premiered in 2013, Christy, a recovering addict like her mother, was trying to get her life on track. A single mother with two kids — teenager Violet (Sadie Calvano, "The Perfect Daughter") and young son Roscoe (Blake Garrett Rosenthal, "Bridesmaids," 2011) — she was working as a waitress when her estranged mother waltzed back into her life. Over the years, the women have attempted to make amends for lost time while also striving to maintain their sobriety.

Created by TV hitmaker Chuck Lorre ("The Big Bang Theory"), along with Gemma Baker ("Two and a Half Men") and Eddie Gorodetsky ("The Big Bang Theory"), the comedy has been popular with audiences from the get-go. Throughout its run, "Mom" has developed a reputation for frequently tackling real-life issues such as drug addiction, death, domestic violence and rape. The series has been praised over and over again for its ability to balance the seriousness of such topics with humor. At the time of the show's Season 6 renewal, CBS executive Kelly Kahl boasted, "It's a fearless series that tackles provocative social issues with laughter and grace, and a large, loyal audience has followed."

Unfortunately, that "large, loyal audience" has dwindled in the past year, possibly in response to Faris's absence. In September 2020, Faris announced she would not be returning to the show, despite being in the middle of a two-year contract that should have seen her through until the end of Season 8. In the script, Christy has moved to Washington to attend Georgetown University. However, the reasons behind the actor's departure are not quite as clear. At the time of the announcement, Faris released a statement expressing gratitude for her time on the show.

"The past seven years on 'Mom' have been some of the most fulfilling and rewarding of my career," Faris said. "I'm so thankful to Chuck [Lorre], the writers and my amazing castmates for creating a truly wonderful work experience. While my time as Christy has come to an end, allowing me to pursue new opportunities, I'll be watching next season and rooting for my TV family."

Beth Hall, Mimi Kennedy, Allison Janney and Jaime in a scene from "Mom"

Janney has been left to carry the series without her TV daughter, something the seven-time Emmy winner is well suited to do. Her performance as Bonnie has been lauded by many critics throughout the show's run, earning her back-to-back Primetime Emmys in 2014 and 2015. As Bonnie picked herself up after Christy's departure at the beginning of the new season, she focused on her marriage to retired stuntman Adam (William Fichtner, "Prison Break").

Season 8 has also zeroed in on Janney's other talented co-stars as Bonnie leans on the friends she and Christy made while attending their Alcoholics Anonymous meetings. Mimi Kennedy ("Homefront") appears as Marjorie, Bonnie and Christy's AA sponsor who has a sordid past; former model Jaime Pressly ("My Name is Earl") plays Jill, a divorced wealthy socialite who has relapsed more than once; Beth Hall ("Mad Men") portrays registered nurse Wendy, who is often overly emotional; and Kristen Johnston ("3rd Rock from the Sun") rounds out the main cast this season as Bonnie's one-time foster sister, Tammy, who was recently released from prison.

Other key players over the years have included Matt Jones ("Breaking Bad") as Christy's ex-husband, Baxter, Johnston's former "3rd Rock" co-star French Stewart as Chef Rudy, Nate Corddry ("New Girl") as Christy's one-time love interest Gabriel, and Spencer Daniels ("Star Trek," 2009) as Luke, the father of Violet's baby.

While there is no doubt there is plenty of talent to go around on "Mom," the series has seen a big drop in the ratings this season. That likely had something to do with the show's cancelation, a decision that was announced in February. The comedy had been a strong performer for the network over the years, peaking in Season 2 with more than 11 million average viewers and holding strong until Season 7 with more than eight million average viewers. But Season 8's ratings have slipped, and with around just five million average viewers, "Mom" is down about 20% from last season in key demographics without Faris.

The news of the cancelation reportedly came as a surprise to the cast and crew, not to mention fans. Luckily, the show will likely live on in syndication. For now, audiences can enjoy one last glimpse into the life of Bonnie and her friends in the series finale of "Mom," airing Thursday, May 13, on CBS.