Global burden of depressive disorders: The issue of duration

The Global Burden of Disease (GBD) study The Global Burden of Disease (GBD) study examined the impact of 107 major diseases examined the impact of 107 major diseases in a comparative framework including both in a comparative framework including both mortality and disability.When 'disability' mortality and disability.When 'disability' was taken into account, the formerly un-was taken into account, the formerly unrecognised burden of mental disorders recognised burden of mental disorders became undeniably evident.Mental dis-became undeniably evident.Mental disorders ranked as high as cardiovascular orders ranked as high as cardiovascular and respiratory diseases, surpassing all and respiratory diseases, surpassing all cancers combined and even HIV infection.cancers combined and even HIV infection.Depressive disorders, as a single diagnostic Depressive disorders, as a single diagnostic category, were the leading cause of dis-category, were the leading cause of disability worldwide.These results have ability worldwide.These results have provided the most powerful scientific sup-provided the most powerful scientific support and advocacy for mental health care, port and advocacy for mental health care, because they highlighted loss of human pro-because they highlighted loss of human productivity due to mental disorders (Ustun, ductivity due to mental disorders (U ¨stu ¨n, 1999).1999).From a scientific point of view, the GBD From a scientific point of view, the GBD study is a 'meta-synthesis' of epidemio-study is a 'meta-synthesis' of epidemiological information concerning incidence, logical information concerning incidence, prevalence, duration, severity, associated prevalence, duration, severity, associated disability, age of onset, course and treat-disability, age of onset, course and treatment rates of major diseases as well as ment rates of major diseases as well as mortality due to these conditions.These mortality due to these conditions.These epidemiological indicators are built into an epidemiological indicators are built into an internally consistent model of the disease, internally consistent model of the disease, adjusting for disability (i.e.health levels) adjusting for disability (i.e.health levels) throughout the life span.In calculating the throughout the life span.In calculating the burden of disease, 'duration' is a key driver burden of disease, 'duration' is a key driver -like the length of mortgage that drives -like the length of mortgage that drives your monthly payments.We therefore need your monthly payments.We therefore need to study duration in terms of onset, length to study duration in terms of onset, length and end of an episode with stopwatch preci-and end of an episode with stopwatch precision, and determine the distribution of each sion, and determine the distribution of each element in the general population.element in the general population.