As Melissa McCarthy's latest laugh-delivery apparatus blurped, sputtered and otherwise malfunctioned, the words of another remarkable female artist wafted across my consciousness. In "Liability," Lorde sings, "The truth is I am a toy that people enjoy / 'Til all of the tricks don't work anymore / And then they are bored of me."

If Life of the Party succeeds at anything, it's at making clear the comic dynamo's tricks don't work anymore. Since Bridesmaids launched McCarthy into the show-biz stratosphere in 2011, nobody's blazed more brightly. But things have steadily dimmed for this star. From the turning point that was Tammy (2014) to The Boss (2016), she's been on a downward trajectory.

That deafening thud you heard over Mother's Day weekend? McCarthy's career crashing and cratering. Life of the Party is almost unwatchably awful. Never before has a film starring her opened to less than $20 million at the box office. It's official: I'm bored of her.

Watching a gifted performer run out of gas creatively is never pleasant, but rarely does it make you feel like needles are being jammed into your eyes. A torpid gender-swapping rip-off of Rodney Dangerfield's 1986 smash Back to School, the film offers the super-sappy saga of Deanna Miles, a good-hearted, if empty-headed, fortysomething whose husband (a wasted Matt Walsh) has ditched her for an "upgrade" (a wasted Julie Bowen).

Luckily for the middle-aged mom, the problems caused by the breakup are quickly fixed by returning to Decatur U to finish work on the degree she didn't complete the first time around. An even bigger break: Her daughter, Maddie (Molly Gordon), a senior there, is pleased as punch to have her around after maybe five awkward minutes. It gets less credible, folks.

Maddie's friends can't get enough of Deanna, either. In the entire student body, there are exactly two mean girls. They mock her mom perm and her tacky sweaters. Then (spoiler alert) they decide "Dee-Rock," as her new BFFs have nicknamed her, is kinda cool after all.

I'm not sure which is sadder, the random '80s-themed dance-off during which Dee-Rock does the Worm, or the mandatory scene in which she accidentally gets stoned. Or perhaps it's the oral presentation during which her body inexplicably creaks, cracks and collapses, or her tasteless carnal cavort-athon with a hunky undergrad. Imagine for a second the outrage that would greet a male actor McCarthy's age making like Caligula with a coed.

Then there's the sad fact that every tedious, unbelievable minute of the movie originated in the imaginations of McCarthy and her husband, Ben Falcone. The couple wrote the screenplay; he directed (as with Tammy and The Boss). They literally have no one to blame but themselves.

Nonetheless, there's hope. McCarthy's background is in improv. She was so fabulous in Bridesmaids because director Paul Feig let her rip. I've seen outtakes from Judd Apatow's This Is 40 that are as rapid-fire inspired as anything in her films. But improv and screenwriting use different parts of the brain, or that was my theory.

I checked in with noted neuroscientist David Låg Tomasi, PhD, EdD-PhD, MA, MCS, AAT, who concurred and referred me to a paper titled (honest) "The Neuroscience of Improvisation."

It's simple. All a return to greatness requires is a return to the sorts of supporting roles that permitted McCarthy to access the part of her brain that made her a comic phenomenon. She's neither a screenwriter nor a lead actress. She's an improv ninja.

You can't argue with science.