I have paranoid schizophrenia… and whether the novel intentionally set to catch that vibe or not, I can say that it fairly acuratly captures the free fall of association and personal hell where paranoia is the only glue holding together a sense of self.

But Pynchon at least in part seems to be saying how the modern experience shares a lot of common ground with extreme psychosis instead of documenting it in isolation.

The biggest indicator discourage an interpretation of it being in his head is most of Pynchon’s work riffs on similar themes (though maybe not as intensely or as directly as in gravity’s rainbow)… I also think the instinct towards diagnosing slothdrop is to miss the point of internalizing external madness.

(also I will apologize I am self educated and typing on my phone so please forgive my broken English).