Far be it from me to tell a theater full of people merrily chuckling away that what they're laughing at isn't funny. For it was in just such a room that I saw Eighth Grade, the first feature written by Bo Burnham, and most of the crowd was having a fun time, while I felt so agonised that I wanted to claw the skin off my body to escape.

That's a compliment, by the way. Eighth Grade's monumental title exactly describes its content, which is specifically the story of one week in the life of awkward, friendless 13-year-old Kayla Day (Elsie Fisher), but is more generally an attempt to capture in cinematic form the psychological state of being an awkward, friendless 13-year-old. It is structured like a comedy, for sure, though one in which each and every last joke is based in cringe humor. But in effect, I received it much more like a horror movie, and frankly a much better horror movie than most of the ones that get released: the most that your average horror movie can ever hope for is to throw enough well-executed jump scares at you that you get a good adrenaline high going, but Eighth Grade is so pulverising, so consistently across its 94 minutes, that it leaves one with a hopeless despair that it really is a cruel and unmanageable world full of arbitrary, pointless suffering, and the best we can hope for is to laugh, caustically and humorlessly, out of the knowledge that we, at least, did not die on our way through it.

Mind you, I don't even know that I think Eighth Grade does that, though it's entirely possible Burnham meant for that to be the case. From where I stand, what the film does best is to create an unendurable feeling of sympathetic anguish for Kayla. I should mention sooner rather than later: this is not a film that I personally relate to on any level. I was an extremely happy 13-year-old who cared exactly not one iota about the good opinion of other 13-year-olds. So this isn't a thing where the movie is reminding me of my own past trauma: it is using the stuff of cinema to create that trauma out of thin air. Given my recent affection for movies that have used form to make me so anxious that I became physically ill, I found this entirely successful, though it's going to be a very long time before I even think about watching Eighth Grade again, if ever.

What we have here is a film made out almost entirely of incidents - there is in the very strictest sense a "plot", in that events take place onscreen in a set order, but there's very little of a narrative arc. Basically, Kayla pours all of her anxiety into YouTube videos that are watched by virtually nobody, in which she offers advice that corresponds to exactly whatever social stressor is preying upon her in that particular moment, and which advice is meandering, sometimes incoherent, and always trite. But heartfelt! That is the main emotional takeaway of the film: that Kayla is a sincere person who feels deeply and wants to express those feelings, and she is forever and always obliged to enact the social codes of well-off United States suburban eighth graders in the second decade of the 21st Century. I cannot speak to the film's depiction of those codes or that very specific culture, but I can say this: thank the good Lord and all the little angels that social media didn't exist until I was all the way out of the educational system, because it looks like hell.

So yes, hell. The film, as I said, is mostly incidents, and these are never altogether good and rewarding incidents. Often, they are absolutely gut-wrenching, as in the film's most bone-chilling scene: Kayla, having spent the day with a bunch of high school seniors, ends up alone in a car with a lanky, inarticulate boy (Daniel Zolghadri), who attempts to use every passive-aggressive trick to coerce her into having sex with him, and everything about the scene is calculated to maximise a feeling of pure draining terror: the smudgy edge lighting and claustrophobic shots emphasising the shape of the car's interior by cinematographer Andrew Wehde, the flat loudness of the sound mix, and especially the unfocused, mumbling acting, with Fisher's huge-eyed look of confusion, embarrassment, disgust, and fear dominating the shots (Fisher has terrifically expressive, disproportionately large eyes that she uses to great effect throughout the entire movie, even in a negative sense: given how much her big open eyes communicate, when she tightly closes them, it creates an excellent sense of snug tension).

But that's the kind of moment that's supposed to make your skin crawl. What really impresses me about Eighth Grade is when it gets that kind of effect from quotidian moments. At one point, Kayla summons up the courage to call the high school senior Olivia (Emily Robinson) whom she "shadowed" earlier that day, and they have a lovely, upbeat conversation: Burnham stages this conversation in one take, in medium close-up, swinging back and forth to follow Kayla as she nervously paces back and forth in her bedroom at top speed. It's pure visual chaos, and it exactly matches the sense of nervous excitement in the character at that moment, and it made me so tense I felt my legs shaking. That's the movie: injecting all of Kayla's bad, overclocked feelings right into us, and letting us watch from the outside when she tries to rev herself up into feeling something good.

As an exercise in screen empathy, this is all amazing stuff, though it is terribly tiring to watch. I don't think it has anything actively insightful to say about its topic (its theme is that being 13 years old sucks a lot and it seems like there's no way out; this is the theme also of basically every other work of art about early adolescence), although it says it with great fire and conviction, and with a terrific performance from Fisher, who holds back absolutely none of her character's hurt - the number of moments when we see Kayla wince is impressive all by itself. Just about the only relief the film has to offer are the scenes between Kayla and her dad Wes (Josh Hamilton), a warm and sweet grounding presence, who always takes over as the audience's identification point when he shows up and allows us a way to keep in mind that yes, this is all temporary, and being a grown-up is much more clarifying than being a teenager and all that. When the film is loving and funny, it's because he opens it up to be those things. Otherwise, it is totally harrowing, an acutely honest depiction of adolescent frustrations and suffering that apologises for nothing and pulls no punches. Like I said, I think I'll never watch it again - it's a huge bummer of a movie, and wearying - but I'm certainly impressed by it.