Allison Janney Says 'Mom' Getting Canceled After 8 Seasons Was 'a Shock': 'I Have My Own Theories'

Robert Voets/Warner Bros. Entertainment Anna Faris and Allison Janney on Mom

Allison Janney is bowing out as Bonnie Plunkett this week when the final episode of Mom airs after eight seasons on CBS.

The seven-time Emmy Award winner, 61, reflected on the sitcom's ending during a recent interview with CBS Sunday Morning. "Yeah, it was a shock," Janney said of the show announcing its end. "I have my own theories, but I've been told not to express them. But listen, eight years is a great long run for a show."

CBS announced in February that the show was canceled after premiering in 2013, and Janney ventured to guess that the reason was "probably money"-related.

"Getting to be part of Mom these past 8 years...showing the laughter, love and hope that can come with recovery, has been one of the great honors of my life," she reacted to the news on Instagram at the time.

Janney's onscreen daughter Anna Faris departed the show in September, just before the first day of production on season 8.

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Janney stars as a recovering alcoholic who reconnects with her estranged grown daughter Christy (Faris), who's overcoming her own struggles with addiction. They find community in a group of women from their Alcoholics Anonymous meeting, played by Jaime Pressly, Kristen Johnston, Mimi Kennedy and Beth Hall.

"You know, it's one thing to be part of a show that entertains, which in and of itself is a wonderful thing," Janney told CBS Sunday Morning. "But to also have an impact on people who are in recovery, or people who have loved ones or family members who are going through it, to make recovery a more approachable option."

It particularly resonated for her, after she lost her brother Hal Janney to addiction 10 years ago. "I just – I just miss his sense of humor, really," she said, revealing she still calls him.

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"My favorite time to talk to him was when I was in the car driving someplace, so I always think of him when I'm in the car," Janney explained. "And I still have his phone number, and I dial it."

The final episode of Momairs this Thursday on CBS, but Janney isn't quite ready to bid farewell. "I hate change," she said. "It makes me … I get afraid – I always have – to let something go and not know what's next. I think the biggest thing I need to learn how to say is no."

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The Oscar winner also revealed that she's worn a wig to play her character for the past eight years, now rocking a short natural grey 'do. "It was pretty funny, though, when I came to show up for our first Mom episode in October when we started in 2020," Janney recalled.

"And the producers were like, 'What have you done? Bonnie can't – how are we gonna explain this?'" she recounted. "I'm like, 'You guys, I've been wearing a wig since season 1!' None of them knew that I had been wearing a wig. So, you know, now all of America knows that I was wearing a wig!"

The I, Tonya actress revealed she was going for "a Helen Mirren thing" with the new look, when she appeared on PEOPLE TV's One Last Thing in February. "It started out with just COVID choices, you know," she said.

"I was in Ohio for five months of the pandemic," Janney explained. "My natural color started growing in — which is gray. And then I thought, you know, I've always wanted to cut it off and do a Helen Mirren thing. I just wanted to try it ... I just get very brave with my hair."

The series finale of Mom airs May 13 on CBS.