The subject matter of delusions seems to reflect the current culture in a particular time and location. For example in the US, during the early 1900s syphilis was a common topic, during the second world war Germany, during the cold war communists, and in recent years technology has been a focus. Some psychologists, such as those who practice the Open Dialogue method believe that the content of psychosis represent an underlying thought process that may, in part, be responsible for psychosis, though the accepted medical position is that psychosis is due to a brain disorder.