Recent trends in the use of antidepressant drugs in Australia, 1990–1998

OBJECTIVE: To determine the pattern of use of antidepressant drugs in the Australian community, 1990-1998, and to compare this with those of other developed countries. DESIGN: Retrospective analyses of prescription and sales data, together with information about patient encounters for depression (from an ongoing survey of service provision by general practitioners) and population-based prevalence estimates for affective disorders (from community health surveys). MAIN OUTCOME MEASURES: National and international consumption of antidepressants, expressed in defined daily doses (DDDs) per 1000 population per day. Changes in both the frequency of general practice patient encounters for depression and population-based prevalence estimates for affective disorders. RESULTS: Dispensing of antidepressant prescriptions through community pharmacies in Australia increased from an estimated 12.4 DDDs/1000 population per day in 1990 (5.1 million prescriptions) to 35.7 DDDs/1000 population/day in 1998 (8.2 million prescriptions). There has been a rapid market uptake of the selective serotonin reuptake inhibitors (SSRIs), accompanied by a decrease of only 25% in the use of tricyclic antidepressants (TCAs). In 1998, the level of antidepressant use in Australia was similar to that of the United States, while the rate of increase in use between 1993 and 1998 was second only to that of Sweden. In Australia, depression has risen from the tenth most common problem managed in general practice in 1990-91 to the fourth in 1998-99, and the number of people reporting depression in the National Health Surveys (1995 v 1989-90) has almost doubled. Of the prescriptions dispensed in 1998 for antidepressant drugs subsidised by the Pharmaceutical Benefits Scheme, 85% were written by general practitioners, and 11.2% by psychiatrists. CONCLUSIONS: As in most developed countries, antidepressant use increased between 1990 and 1998. The rapid market uptake of the new antidepressants, particularly SSRIs, is likely to have been driven by increased awareness of depression, together with availability and promotion of new therapies.