There is an ongoing search for suitable endophenotypic parameters in schizophrenia. Neuroimaging evidence suggests that there is a disturbance of the frontal gyrification pattern in schizophrenia. Interestingly, this disturbance is correlated to cognitive deficits and negative symptoms. Furthermore it is interesting to note that there are new developmental disorders like the Williams Syndrome being accompanied by disturbed gyrification where the exact mutation is already known. The aim of this symposium is to gather the knowledge about disturbed gyrification in psychosis which is very likely to be a future endophenotypic marker to monitor persons at-risk and possible even the long-term cause of the illness.