On a certain level, ‘I Smile Back’ is one of those “sad clown” casting gimmick movies – you know, the ones where a person who previously specialized in chuckles shows that they’re so much deeper. It can be a frustrating way to launch an uninteresting movie. Or, in the case of something like ‘I Smile Back’, it can be a fascinating revelation.

This time, it’s Sarah Silverman who gets the chance to try on some serious shoes, and she’s absolutely extraordinary. That probably shouldn’t be too surprising since her comedy has always relied on deadpan character performance and delved into deeply uncomfortable areas to reveal awkward truths. Even so, it’s surreal to see Silverman throw herself so fearlessly into such a dark role and deliver such an incredibly impressive performance. The movie itself is almost a bonus wrapped around her, but thankfully it’s pretty good too.

Silverman stars as a depressed housewife named Laney. In the opening scenes, we see her passively playing wife for her nice-to-a-fault husband (Josh Charles) and mother for her children (Skylar Gaertner and Shayne Coleman), but it’s clear that her heart isn’t in it. By the end of the movie, it’s not quite clear where her heart is at all, to be honest. Laney certainly seems more comfortable at a cocaine-and-anal-sex hotel fling with a man who decidedly isn’t her husband than she was caring for her family that morning. From there, her self-destruction and depression only spiral further. A bottoming-out point comes by violating a teddy bear on her daughter’s bedroom floor while the child sleeps. That finally gets Laney into rehab, but from the moment the staff starts discussing the difficulty of checking in “for the first time,” it’s clear that no one believes this will be a one-stop cure, especially not Laney herself. The story doesn’t exactly get any cheerier from there.

So, what we have here is essentially a ‘Bad Lieutenant’-style tale in a housewife’s world. Director Adam Salky and writers Paige Dylan and Amy Koppelman (adapting her own novel) are remorseless in their depiction of the character. They make no attempt to pander for sympathy or offer easy explanations for Laney’s behavior. Even a telling visit to her long lost father, sensitively portrayed Chris Sarandon, offers as many questions as answers. Instead, this is a painfully honest portrayal of the self-destructive spirals that claim the lives of too many. At times, the movie can be a bit much to take, in a way that’s both a compliment and a demerit. It’s a deeply unpleasant viewing experience by design and can’t help but be frustrating to watch. The filmmakers could certainly be accused of dabbling in misery porn, but at least it’s good misery porn.

Of course, the reason ‘I Smile Back’ was made and the reason to watch it is Sarah Silverman. She’s absolutely astounding in the central role, disappearing into a damaged shell of a woman without relying on any of the trademark tics and tricks that made her a star. It must have been punishing to play and certainly is to watch. The performance is akin to an 85-minute open wound festering in front of the audience. That’s as unpleasant to watch as it sounds, yet for anyone who has enjoyed Silverman’s work, it demands a viewing as a testament to her talents.

For far too long, Silverman has been saddled with token girlfriend and wisecracking best friend roles in projects that she didn’t’ conceive for herself. ‘I Smile Back’ proves that her potential as an actress has long been untapped. Not only does she deserve any and all accolades coming her way, but hopefully the movie will help filmmakers see her in a new light in the future. This could be the beginning of a new chapter in her career. Given how well the first page turned out, it’ll be exciting to see where she goes from here.