Karen (Catherine Tate) is basically having what you would call a mid-life crisis. Her mother is turning senile and her daughter is behaving like most teenage daughters do. She's living her life straight out of "The Bad Mother's Handbook".
The title is half accurate, but it should also be "The Bad Daughter's Handbook". Mother and daughter are very selfish, rude and inconsiderate people. As the title suggests, they behave badly. So I guess I should have known what I was getting myself into, but this is only a drama, not a comedy. None of their "bad behaviour" played out for laughs. We were apparently supposed to care for these people. But the only people I cared for were the supporting characters that the mother and daughter treated badly. And they don't just treat other people badly, they treat each other badly. It's just a whole lot of unhappiness for a sense of self-importance and self-gain.
The other "rave" reviews praised Catherine Tate's performance and how good of a made-for-TV movie this is. Those points are accurate; Tate played the "bad mother" exceptionally well, and the film as a whole played out with much more emotion than most made-for-TV movies do. I just think the film should be rated on more points than just that. If you like the idea of the title "The Bad Mother's Handbook" played out very slowly with drama instead of comedy, and you like watching selfish characters live their self-important lives, then you just might like this film. But for everybody else, tell your mother you love her, and don't watch this.
