I think she might have had some kind of onset of schizophrenia because she was already nuts when she was working at her first law firm after her clerkship and wrote that deranged novel attacking her judge (Dolores Sloviter).
I don't believe she has schizophrenia at all.
What she does have is a vast reservoir of rage, resentment, envy and hatred that goes back to her childhood as a weird, brown minority kid who didn't fit in. And I think it crystallized in adolescence, and through her college years.
Oh, and Narcissistic Personality Disorder, too.
Her rage at white women reminds me of incels' rage at "Stacy," the stand-in for all the women they can't have. In Rao's case, I think she's trapped in her own blind fury at white women (especially affluent ones, of her own social class) because she can't be one of them. At various times of her life, they've seemed to easily get all of the things she's wanted, and felt entitled to, and been denied, and that just burns her ass.
I can guarantee that boys didn't have crushes on her in middle school, and she didn't get dates in high school. I also doubt she had any friends. And I can't chalk that up to simple racism, or even cultural differences; upper middle-class white kids at the time she was in high school would have tried to include her, if she was friendly and easy to be around. But given what a malignant NPD shitshow she is now, I suspect her personality was already arrogant, entitled, quick to take offense, and prone to black-and-white thinking even then, and that's what drove others away.
The specific focus of her hatred is exactly what I would expect to see in a teenaged girl who keeps watching all of the other girls date, have friends, attend prom, and basically live out all the standard American popular high school girl experiences, from the sidelines, while being continually excluded by them (or at least not included in the way she believes she ought to be). Maybe she also had demanding parents, pushing her to focus on academics at the expense of socializing, or who forbade dating and other forms of socializing for cultural reasons, but given the way she focuses so intensely on white women, I don't think that's what's behind her rage. I think straight-up envy is.
So got through high school, and went to college, where it was more of the same—white girls having the time of their lives socially and sexually, and still graduating and going out into the world to lead the lives of their choosing, despite not grinding away academically as hard as Saira did.
Why law school? Why not medicine, or tech, or any of the other STEM fields Indian Americans gravitate towards? Probably because she'd had enough exposure to left-wing radical thinking by then, and liked the idea of using the law to punish the kinds of people she hated. Bitter at the existence of so many nails, she decided to become a hammer, because just as a lot of people who go into mental health professions are driven into it by their own issues, a lot of people who go to law school are driven into it by their grievances with, and anger at, the system.
But she was too fucking crazy, too eaten up with rage, resentment, and envy, to even be a lawyer—she just couldn't keep a lid on it, or channel it in a direction that looked remotely sane and justifiable. Her Narcissism didn't help her, but most intelligent Narcs can be extraordinarily charming, and adept at playing social games to get along and get ahead. Clearly, that's not the case with her.
She's a truly repellent human being, but she's a fascinating case study. She's just so over the top in her hatefulness, I can't even get mad about her, because it's obvious that there is no joy in her life, just whatever fleeting pleasure she can derive from humiliating the kinds of white women who have already been enculturated into racist self-loathing.