Abstract
The nature of language difficulties in people with severe mental illness (primarily psychotic disorders and personality disorder) will be considered. Issues relevant to assessment such as enduring developmental problems presenting in adults and the possible reasons why a language skill may not be evident will be discussed. An assessment designed to examine speech, language and communication skills in people with severe mental illness will be presented with findings from a two year cohort of severely mentally ill hospitalised patients. The findings suggest very high levels of speech, language and communication difficulties in this population. The findings will be compared to other related populations. Examples of patients will be used to illustrate diagnostic issues and the relevance of communication skills to other verbally mediated interventions