Emil Kraeplin is considered the father of modern psychiatry. Kraeplin was the first to hypothesize that brain damage might cause a disorder that he named dementia praecox (Asami, Narita, & Hirayasu, 2004). He named it dementia praecox because dementia means intellectual deterioration and praecox means early onset, which are the two things he focused on in regards to the disorder. The main symptoms he believed played a role in dementia praecox were hallucinations, delusions, negativism, attention difficulties, stereo typed behavior, and emotional dysfunctions (Neale & Oltmanns, 1980).
Kraeplin came up with early subtypes for dementia praecox. He came up with one called paranoid type which involved delusions, catatonic type that involved motor dysfunctions, and hebephrenic that involved emotional incongruity. He then also came up with a fourth type called simple which had no specific symptom related to it (Neale & Oltmanns, 1980).
Kraeplin also hypothesized that these people had shortened attention spans, but could stare off into space for long period of time. He thought that their thinking was difficult because their minds were empty, and because of this, their conversations would wonder from one thing to another (Neale & Oltmanns, 1980)
In 1911, Eugen Bleuler changed the name of dementia praecox to schizophrenia. He thought that there were certain symptoms that all patients of schizophrenia had to have, and that no other disorder could have these symptoms. These symptoms included associative disturbance, autism, affective disturbance, and ambivalence. He also thought that there was a primary symptom and a secondary symptom, and the primary symptoms seemed to be caused by organic disease, which he also thought was the cause of the actual schizophrenia. The secondary symptoms came from environmental and experiential factors along with the organic disease (Neale & Oltmanns, 1980).