Writing when writhing with psychosis: a computational linguistic autopsy of Vaslav Nijinsky's diary

'God of Dance' Vaslav Nijinsky wrote profusely during a short period in 1918-1919, immediately preceding his diagnosis of schizophrenia and long-term confinement. This diary, in its uncensored form, constitutes one of the most extensively documented ex tempore first-person accounts during psychosis. It offers a chance to explore the impact of psychosis on writing-not just on what one writes, but also how one writes under such torment. The text generates a pervasive impression of repetitive, meandering thought-invoking suspicions of being a product of formal thought disorder-an affliction that lies at the core of schizophrenia. We study the specific linguistic structure of this diary using computational approaches, comparing it to a word-count-matched control text composed by his wife, Romola Nijinsky, to characterise what the writing does show. Our computational analysis reveals intact topic-level discourse organisation with adequate surface-level coherence. But this apparent coherence is generated via repetition of words-indexing an inability to escape a narrow lexical repertoire-a pattern we term the perseveration paradox Furthermore, first-person pronoun usage was 5.45-fold higher than in the control text, and its removal reduced coherence and increased perplexity, demonstrating that the self-pronoun 'I' functioned as a structural scaffold for Nijinsky's thought in written text. All findings replicated on the original Russian manuscript, confirming robustness despite translation. Nijinsky's diary is not simply a document of suffering or a record of thought disorder; it is an unwitting self-portrait of a mind condensing around a fixed, narrow repertoire of words and the concepts they stand for.