A comparison of antidepressant use in Nova Scotia, Canada and Australia

The prevalence of major depression is reported as approximately 8% in Canada and 7.5% in Australia, the use of antidepressants is therefore common. However, questions remain about whether depression is under-diagnosed and whether patients are appropriately treated with antidepressants once the disorder is recognized. We compared the use of antidepressant medicines, in Nova Scotia, Canada and Australia, in populations receiving public drug subsidy.

The Nova Scotia Pharmacare Program and the Pharmaceutical Benefits Scheme in Australia were used to obtain dispensing data for all publicly subsidized antidepressants. Utilization was compared from 2000-2003, using the World Health Organisation Anatomic Therapeutic Chemical (ATC)/Defined Daily Dose (DDD) system.

The use of antidepressants increased in both areas over the study period. However, the use of antidepressants in Nova Scotia increased at a significantly higher rate than Australia. Selective serotonin reuptake inhibitors (SSRIs) were the most commonly prescribed class of drugs in both areas, constituting 60% of all antidepressants prescribed. Eight different antidepressants made up 90% of the antidepressant drug use in Australia, with sertraline the most commonly prescribed. Similarly, nine different antidepressants made up 90% of the antidepressant use in Nova Scotia, with paroxetine most commonly prescribed.

This study found differences in the rate but not class of antidepressant prescribing in Nova Scotia and Australia. Antidepressant use increased in both areas over the time period. This may be due to increased exposure to marketing, promotion, education or different prescribing practices in Nova Scotia compared to Australia.