A critical review of the data in the literature and their interpretations is given. There are three main lines of interpretation: --The neuropsychological point of view interprets personality disorders as a reaction to the language deficit; --the anatomical point of view tries to relate personality disorders to the location and extent of brain lesions; --the historical point of view links personality disorders to the pre-morbid personality. All of them seem to have shortcomings and to be based at least in part on inadequate scientific methods including the principle problems of psychologically testing aphasics, of not having pre-morbid personality tests or using tests which are developed outside the field of neuropsychology. We suggest the development of multifactorial approaches which take into account biological, sociological and psycho-individual variables in an interactive way.