Psychosocial aetiology of chronic disease: a pragmatic approach to the assessment of lifetime affective morbidity in an EPIC component study

Objectives-The Health and Life Experiences Questionnaire (HLEQ) was develop ed for use in a prospective cohort study of 25 000 men and women living in Norfolk and forms a component study of the European Prospective Investigati on into Cancer and Nutrition (EPIC). The HLEQ includes an assessment of moo d status over the Life course allowing a Limited capacity for the impositio n of diagnostic criteria to enable eventual evaluation of mental health sta tus for chronic disease outcomes. This paper reports estimates of HLEQ Majo r Depressive Disorder (MDD) prevalence and compares them with those obtaine d through interviewer-based methods. In addition evidence for the impact of recall, clustering or cohort effects on these estimates are examined. Participants-3491 eligible respondents to EPIC in Norfolk, aged 45-74 ears, recruited from the first five general practices who completed the HLEQ. Main results-MDD prevalence estimates were found to be closely comparable t o those obtained recently (by interview) in the UK and to those lifetime MD D rates determined through international studies. Risk of MDD onset was fou nd to vary with age as expected from earlier studies using interviewer-base d assessments. Limited evidence was found to show that the distribution of first onset MDD episodes were compressed during the immediate pre-assessmen t period. Results were also consistent with previous evidence demonstrating the raised risk of MDD among women and of the decline in gender difference s with advancing age. Conclusions-These results suggest that estimates of putative, MDD diagnosti c status, derived through the HLEQ, and of associated demographic risk are similar to those derived by more intensive and costly assessment methods. I mplications for the future study of MDD both as an outcome and as a risk fa ctor for chronic disease are discussed.