Lars Lindstrom is a loveable introvert whose emotional baggage has kept him from fully embracing life. After years of what is almost solitude, he invites Bianca, a friend he met on the internet to visit him. He introduces Bianca to his brother Gus and his wife Karen and they are stunned. They don't know what to say to Lars or Bianca--because she is a life-size doll, not a real person and he is treating her as though she is alive. They consult the family doctor Dagmar who explains this is a delusion he's created--for what reason she doesn't yet know but they should all go along with it. What follows is an emotional journey for Lars and the people around him.
Lars is diagnosed in the movie by a family doctor/psychologist as having a delusional disorder. In my world, a delusion is defined as a fixed false belief. For a diagnosis to be made, the person has to 1) experience the delusion for at least a month, 2) can't experience them a direct result of being under the influence of a substance. The other requirement is 3) that the person's behavior not be odd or bizarre apart from the delusion. Lars actually manages to support himself by going to work, attending church, etc., so he meets all these qualifications.
The delusion Lars suffers from is "non-bizarre," that is, it could be plausible, as opposed to bizarre. While we might all think Lars is off his rocker, his frame of mind around Bianca as his girlfriend is logical, other than being based on an improbable foundation.
Let's look at Lars most closely. He's socially inept but very sweet and likable. He runs from his interested co-worker Margo, doesn't like to be touched, and is basically happy living in the converted garage of the house he and his married brother inherited from his father. When Lars announces that he's met a wheelchair-bound missionary on the Internet, he introduces Bianca, a RealDoll sex doll (who he shows no sexual interest in at all). They convince him to take Bianca in to the doctor in order to get Lars' mental health checked out. Funnily enough, the doctor diagnoses Bianca with "low blood pressure," and advises Lars to bring her in weekly for treatments (pretty dang slick of the gal).
The townspeople accept Bianca as a real woman because they love Lars. If it wasn't so crazy, it would actually be quite touching. As a result, Lars becomes more social. He still meets with the doctor weekly, and his painful past becomes apparent in that his father changed and became very distant when his mother died (as a result of giving birth to Lars). The viewer can even see that Lars still carries a baby blanket around with him....clearly he isn't okay.
SPOILERS EXIST BELOW...READ AT YOUR OWN RISK!
Eventually, Lars' delusional dependence on Bianca as an emotional crutch dissipates. Margo had begun to date another guy, and this bothered Lars. He comforts her when they break up, and even touches her hand without his gloves on, which is very symbolic. By the end of the movie, Lars had broken up the delusion in his own time in his own way (Bianca is "unresponsive" one morning and has to be taken to the doctor...eventually she "dies"). At her funeral, Margo and he seem to be connecting on a deeper level.
As crazy as this flick was, Ryan Gosling did a great job acting. He had several scenes alone with a non-responsive sex doll. I mean, how hard would that be to do and not crack up?
But it does show the way a delusional disorder works....so check it out.