Dream speech (in German Traumsprache) is internal speech in which errors occur during a dream. The term dream speech was coined by Emil Kraepelin in his 1906 monograph titled Über Sprachstörungen im Traume ("On Language Disturbances in Dreams"). The text discussed various forms of dream speech, outlining 286 examples. Dream speech is not to be confounded with the 'language of dreams', which refers to the visual means of representing thought in dreams.
Three types of dream speech were considered by Kraepelin: disorders of word-selection (also called paraphasias), disorders of discourse (e.g. agrammatisms) and thought disorders. The most frequent occurring form of dream speech is a neologism.
Kraepelin studied dream speech because it provided him with clues to the analoguous language disturbances of patients with schizophrenia. Still in 1920 he stated that "dream speech in every detail corresponds to schizophrenic speech disorder."
While Kraepelin was interested in the psychiatric as well as the psychological aspects of dream speech, modern researchers have been interested in speech production in dreams as illuminating aspects of cognition in the dreaming mind. They confirmed one of the findings of Kraepelin.
Dream speech opens up a new perspective on the psychiatrist Kraepelin, usually seen as the spiritual father of the DSM system of classification of psychiatric diseases and of biological psychiatry. However Kraepelin, one of the first disciples of Wilhelm Wundt, took a lifelong interest in psychology and even edited a journal Psychologische Arbeiten. As one of the booklets of this journal a 104-pages article on dream speech appeared early in 1906, before the 105-pages monograph was published end 1906.
In his monograph Kraepelin presented 286 examples of dream speech, mainly his own. After 1906 he continued to collect samples of dream speech until his death in 1926. This time the dream speech specimens were almost exclusively his own and the original hand written dream texts are still available today at the Archive of the Max Planck Institute of Psychiatry in Munich. These new dream speech specimens have been published in 1993 in Heynick (in part in English translation) and in 2006 in the original German, with numerous valuable notes added. The second dream corpus has not been censured and dates are added to the dreams. As Kraepelin in 1906 had been collecting dream speech for more than 20 years, he jotted down his dream speech specimens for more than 40 years, with a scientific viewpoint in mind.