Costs of the principal mood disorders: a study of comparative direct and indirect costs incurred by those with bipolar I, bipolar II and unipolar disorders.

BACKGROUND: While there have been many studies comparing direct and indirect costs engendered individually and nationally by those with unipolar (UP) and bipolar (BP) disorders, there has been no previous study comparing costs across the bipolar I (BP I) and bipolar II (BP II) disorders.
METHODS: We examine direct and indirect costs attributable to a mood disorder in a sample of 44 BP I, 102 BP II and 279 UP patients attending a tertiary referral clinic, and with comparable illness durations of some 20 years and comparable treatment durations. We calculated direct and indirect costs incurred for their lifetime of illness based on relevant cost structures, in Australian dollars.
RESULTS: The mean lifetime indirect costs for BP I patients was $134,318, as against $76,821 for BP II and $68,347 for UP patients, joining with respective health care costs of $26,353, $17,580 and $27, 237, to generate total costs of $160,671/BP I patient, $94,401/BP II patient and $95,584/UP patient. BP I patients differentiated most distinctly in costs as a consequence of a higher prevalence of government benefits, time off work and longer periods in hospital. UP patients had more stable work histories than both BP sub-sets. BP II patients were less likely to be hospitalised than both the BP I and UP patients. LIMITATIONS: Being drawn from a tertiary referral clinic, the study sample is not necessarily representative, with this nuance potentially having influenced cost differences between groups.
CONCLUSIONS: This is the first cost of illness study directly comparing BP I and BP II patients (and with an additional comparison group of UP patients). Findings indicate that BP I illness generates more direct and indirect costs than BP II illness, while the latter was generally comparable with UP depression in terms of the lifetime cost.