wrote his work "Über Aphasie," which was influenced by Broca, Wernicke and Adolf Kussmaul. Lichtheim's work analyzed language abilities and categorized language disorders into seven different aphasias, Wernicke's aphasia being one of them. Wernicke then adopted Lichtheim's aphasia classification and became the Wernicke-Lichtheim model. The Elementary Symptom At the 59th Breslau conference in 1892, Karl Kahlbaum described paranoia based on a case study that Wernicke was familiar with. Wernicke described the case study as an example of what he called the "elementary symptom," which is the notion that there is a single, fundamental symptom and all other symptoms are derived from the elementary symptom. Karl Leonhard also followed Wernicke's studies. Although Leonhard rejected the "elementary symptom" theory because it overgeneralizes symptoms of disorders, he did incorporate Wernicke's psychopathological categories of disorders into Emil Kraepelin's binary system of classification. For example, Leonhard renamed Wernicke's "anxiety-psychosis" as "cycloid psychosis," which does resemble schizophrenia and Bipolar cycling. Kraepelin also rejected the elementary symptom theory by describing all of the clinical aspects of a particular disorder (nosology) in contrast to Wernicke's theory, which attempted to home in on the key symptom instead of looking at each disorder as a whole. The theory of elementary symptom was generally rejected and is not a well-known concept today because of the lack of supporting evidence for the theory. Although the theory itself is not supported in modern nosology and etiology, it does have a general influence in psychopharmacology practices with its notion of a target symptom. Clinical psychopharmacology typically treats particular symptoms instead of disorders and diagnoses as a whole. Modern psychiatry does rest on assumptions that some symptoms result from other symptoms, parallel to Wernicke's theory. Wernicke himself did not pursue research on the elementary symptom theory because of his devotion to aphasiology. One of the fundamental problems with the elementary symptom theory is that Wernicke described anxiety as the elementary symptom of many disorders. This was problematic for the theory because anxiety, to some extent, is seen in almost all psychiatric disorders. This caused the elementary symptom to fail at categorizing clinical descriptions and proper treatments. Another difficulty for Wernicke and other psychologists was determining which symptom was the elementary symptom and given priority over other symptoms that might be just as important to treat and might not be a direct result of another symptom. Lastly, Wernicke preserved traditional German psychiatry and described clinical vignettes,