OBJECTIVES:   To measure the total direct cost of depression and its distribution to different services using administrative databases from Alberta service providers.  METHODS:   We analyzed available administrative databases from Alberta Health and Wellness and the Alberta Mental Health Board from 2005-2006.  The following cost information was obtained:  psychiatric care, community mental health visits, regional inpatient and outpatient services, emergency room visits, and physician visits.  Records were selected if the primary diagnosis for the service was depression disorder using 2006 dollar values.  Data was analyzed by age group.  RESULTS:   Depression in Alberta had a direct health care cost of $97M in 2005-2006, representing 1.1% of the province’s total healthcare costs.  The treated prevalence of depression in 2005-2006 was estimated at 13%.  The greatest cost driver was physician services ($42.6M), followed by acute inpatient costs ($33.8M).  General practitioners incurred half of physician costs and treated nearly six times the number of individuals with depression than psychiatrists.  Per capita cost to treat depression increases with age, with seniors representing the highest cost per individual.  Older adults tend to use and incur a greater cost in inpatient services, while outpatient or physician services are more heavily used by younger age groups.  CONCLUSIONS:   The estimated $97M cost of depression in Alberta is likely to be an underestimation.  We included individual data with a primary diagnosis of depression and could not include drug data or privately funded services.  Our findings are consistent with previous research that people with depression are treated more frequently in primary care and that the cost to treat depression increases with age.  Depression continues to be a heavy cost burden throughout Alberta and worldwide.