Recent reviews lack important information on the high cost-of-illness worldwide for bipolar disorder (BD). Therefore, the present study systematically analyzed those costs, their driving components, and the methodological quality with which the few existing cost-of-illness investigations have been performed.Methods
In June 2012, we conducted a systematic literature review of electronic databases to identify relevant cost-of-illness studies published since 2000. Their methodological quality was assessed. Costs were standardized by first extrapolating them to 2009 using country-specific gross domestic product inflators and then converting them into US dollars via purchasing power parities (PPP).Results
The main characteristics of 22 studies were evaluated. Ignoring outliers, costs per capita ranged from 8,000 to 14,000 US$-PPP for overall direct healthcare, from 4,000 to 5,000 US$-PPP for direct mental healthcare, and from 2,500 to 5,000 US$-PPP for direct BD-related care. Indirect costs ranged from 2,000 to 11,000 US$-PPP. Inpatient care was the main cost driver in three studies; drug costs, in two studies. Methodological quality was deemed satisfactory.Conclusions
The cost variance was great between studies. This was likely due to differences in methodology rather than healthcare systems, thereby making such comparisons difficult. The results showed that BD has a substantial economic burden on society. To gain more evidence, international standardized checklists are needed when undertaking cost-of-illness studies.