Schizophrenia is a brain disorder characterized by a heterogeneous clinical symptomatology. Accordingly, many structural brain changes are not associated directly with clinical symptoms. These structural changes can be detected in the frontotemporal cortex and may correlate with the course of the disease. The most important etiological concept is the neurodevelopmental hypothesis according to which developmental, morphologically detectable changes predispose for the acquisition of schizophrenia. The relevance of neurodegenerative components also remains to be determined. However, it is becoming increasingly clear that schizophrenia is not associated with pathological changes in a circumscribed brain region but with widely distributed morphological changes. Presently, the leading hypothesis for explaining these changes is a frontotemporolimbic network disturbance with cytoarchitectural changes in the heteromodal association cortex. Present research therefore focuses on testing this theory using functional imaging on a macroscopic level and examination of the neuronal cytoarchitecture on a microscopic level.