The fourth edition of his textbook, "Psychiatrie", published in 1893, two years after his arrival at Heidelberg, contained some impressions of the patterns Kraepelin had begun to find in his index cards. Prognosis (course and outcome) began to feature alongside signs and symptoms in the description of syndromes, and he added a class of psychotic disorders designated "psychic degenerative processes", three of which were borrowed from Kahlbaum and Hecker: "dementia paranoides" (a degenerative type of Kahlbaum's paranoia, with sudden onset), "catatonia" (per Kahlbaum, 1874) and "dementia praecox", (Hecker's hebephrenia of 1871). Kraepelin continued to equate dementia praecox with hebephrenia for the next six years.