Scan the literature, search MEDLINE, attend major psychiatry conferences and you'll find several studies estimating the burden of illness, or treatments' relative cost effectiveness, in schizophrenia, depression and anxiety-spectrum disorders. Traditionally, bipolar disorder ('manic depression') attracted relatively little attention from health economists. Now, a new study estimates the annual burden of illness that bipolar disorder places on UK society.1The study was presented at the 7th World Congress of Biological Psychiatry held earlier this year, and has now been accepted for publication in the British Journal of Psychiatry. The study could offer a baseline for considering management costs as new drugs are introduced for this potentially devastating condition.