The Whitehall II study was established in 1985 to investigate the causes of social inequalities in health. Since this first wave of data collection, self-completion questionnaires and clinical data have been collected from the cohort every two to five years with a high level of participation. The study has shown the importance of psychosocial factors such as work stress and work-family conflict in heart disease and diabetes. These are in addition to the contribution of unhealthy behaviours and traditional risk factors (such as high blood pressure). By combining over 30 years of data on social inequalities and chronic disease with new clinical measures of cognitive function, mental disorders and physical functioning, the Whitehall II study has become a world-class, interdisciplinary study of ageing, allowing research on multi-morbidity, functional decline, frailty, disability, and dementia. Study website:

http://www.ucl.ac.uk/whitehallII