Background: Depression is a very common disease with substantial economic consequences. This paper reviews all published cost-of-illness studies of depression worldwide.
Methods: A systematic search of cost-of-illness studies of depression in the databases MEDLINE, Web of Science, Cochrane Library, and PSYNDEXplus was conducted. Identified studies were classified by their basic characteristics. Costs reported were inflated in original currency to the year 2003 and then converted into US-dollar using purchasing power parities (US$ PPP). Additionally, national-costs were converted in costs per case and per inhabitant.
Results: 24 papers with notable methodical differences were identified and classified by their basic characteristics. Summary estimates from the studies for the average annual costs per case ranged from $1000 to $2500 for direct costs, from $2000 to $3700 for morbidity costs and from $200 to $400 for mortality costs. The basic quantity of interest in COI-studies of depression was stated.
Limitations: Methodical differences limited comparison substantially.
Conclusions: Depression is associated with a high economic burden. Conducting COI-studies of depression along the line noted in the review could help provide the opportunity to expose differences in costs associated with different approaches to disease management.