The Genealogy of Dementia Praecox I: Signs and Symptoms of Delusional Psychoses From 1880 to 1900.

We can trace, with high congruence, the clinical syndromes of depression and mania as described over the 20th century in psychiatric textbooks back to 1880 and to the earliest writing of Kraepelin published in 1883. However, this is not the case for Kraepelin's 2 delusional syndromes central to his overall nosology: Dementia Paranoides (later paranoid schizophrenia) and Paranoia. A detailed examination of 28 textbook descriptions of delusional psychoses from 1880 to 1900 reveals a diverse and partially overlapping set of syndromes with an admixture of symptoms and signs that would later be considered indicative of Dementia Paranoides and Paranoia. A similar pattern in seen in Kraepelin's own description of "Primäre Verrücktheit" from the first edition of his textbook (1883). No clear prototypes emerged in these textbooks or in Kraepelin's early writings for the 2 distinct delusional syndromes that would later evolve in his mature writings. Rather, the nosologic approach taken in these writings was symptom based and assumed that a viable diagnostic category could be constituted by including all delusional patients once those suffering from organic or mood disorders were excluded. While Kraepelin used the historical syndromes of mania and depression, with no appreciable change, as building blocks for his category of manic-depressive insanity, his nosologic system for the psychotic disorders-the syndromes of Dementia Praecox and Paranoia-was more innovative and without clear precedent in the prior psychiatric literature.