The burden of mental disorders in Victoria, 1996

Background: Between 1998 and 1999, a burden of disease assessment was carri ed out in Victoria, Australia applying and improving on the methods of the Global Burden of Disease Study. This paper describes the methods and result s of the calculations of the burden due to 22 mental disorders, adding 14 c onditions not included in previous burden of disease estimates, Methods: Th e National Survey of Mental Health and Wellbeing provided recent data on th e occurrence of the major adult mental disorders in Australia. Data from in ternational studies and expert advice further contributed to the constructi on of disease models, describing each condition in terms of incidence, aver age duration and level of severity, with adjustments for comorbidity with o ther mental disorders. Disability weights for the time spent in different s tates of mental ill health were borrowed mainly from a study in the Netherl ands, supplemented by weights derived in a local extrapolation exercise. Re sults: Mental disorders were the third largest group of conditions contribu ting to the burden of disease in Victoria, ranking behind cancers and cardi ovascular diseases. Depression was the greatest cause of disability in both men and women. Eight other mental disorders in men and seven in women rank ed among the top twenty causes of disability. Conclusions: Insufficient inf ormation on the natural history of many of the mental disorders, the limite d information on the validity of mental disorder diagnoses in community sur veys and considerable differences between ICD-10 and DSM-IV defined diagnos es were the main concerns about the accuracy of the estimates. Similar and often greater concerns have been raised in relation to the estimation of th e burden from common non-fatal physical conditions such as asthma, diabetes and osteoarthritis. In comparison, psychiatric epidemiology can boast grea ter scientific rigour in setting standards for population surveys.