Non-fatal disease burden for subtypes of depressive disorder: population-based epidemiological study.

BACKGROUND Major depression is the leading cause of non-fatal disease burden. Because major depression is not a homogeneous condition, this study estimated the non-fatal disease burden for mild, moderate and severe depression in both single episode and recurrent depression. All estimates were assessed from an individual and a population perspective and presented as unadjusted, raw estimates and as estimates adjusted for comorbidity. METHODS We used data from the first wave of the second Netherlands-Mental-Health-Survey-and-Incidence-Study (NEMESIS-2, n = 6646; single episode Diagnostic and Statistical Manual (DSM)-IV depression, n = 115; recurrent depression, n = 246). Disease burden from an individual perspective was assessed as 'disability weight * time spent in depression' for each person in the dataset. From a population perspective it was assessed as 'disability weight * time spent in depression *number of people affected'. The presence of mental disorders was assessed with the Composite International Diagnostic Interview (CIDI) 3.0. RESULTS Single depressive episodes emerged as a key driver of disease burden from an individual perspective. From a population perspective, recurrent depressions emerged as a key driver. These findings remained unaltered after adjusting for comorbidity. CONCLUSIONS The burden of disease differs between the subtype of depression and depends much on the choice of perspective. The distinction between an individual and a population perspective may help to avoid misunderstandings between policy makers and clinicians.