Present State Examination (PSE) A test developed by psychiatrist John Wing and colleagues at the Maudsley Hospital in Britain in the 1960s. The aim was to facilitate the standardized identification of psychiatric cases and to improve psychiatric classifications, both for research and clinical purposes. (Wing is committed to a disease model of mental malfunctioning.) The test is designed to assess the individual's present mental state (questions refer to the past month only) in order to identify any mental pathology. It involves a standard checklist of items, though some flexibility is allowed in questioning, especially in follow-up questions. Interviewers have to be trained but do not have to be psychiatrists.

Analysis of the answers to different questions, in which clinical judgements play a part, allows the data to be transformed into a series of symptom and syndrome scores. Further historical and aetiological information is required if a psychiatric diagnosis is to be generated, and a computer package (CATEGO) has been developed to assist this process.

The Present State Examination has been widely used as a screening instrument in studies of psychiatric epidemiology, both national and international. It has the advantage over the simpler research instruments which attempt to measure ‘caseness’ on a single dimensional scale, in providing measures of a range of syndromes, although behaviour disorders (such as alcoholism and organic syndromes) are not covered. It was the instrument used by George Brown and Tirril Harris to identify depression in community samples in their much discussed volume on Social Origins of Depression (1978) and in their subsequent studies.