Surveys conducted in 1990-91 and 1998-99 by the Family Medicine Research Centre have shown the increasing prominence of depression as a problem managed in general practice.6,7 In 1998-99, depression ranked as the fourth most common general practice problem, compared with the tenth in 1990-91. The rate of patient encounters involving depression per 100 encounters has increased from 2.1 in 1990-91 to 3.5 in 1998-99. In 1998-99, compared with 1990-91, antidepressants were more likely to be prescribed per every 100 encounters for depression (58.4 prescriptions [95% CI, 56.1-60.8] v 52.3 prescriptions [95% CI, 49.2-55.5]).
Comparisons with age and sex demographics for total general practice encounters (women, 58.7%) suggest that female patients were over-represented at encounters for depression.
The most frequent patient age group in encounters at which a tricyclic antidepressant was prescribed was 45-64 years (38%), whereas for encounters at which SSRIs were prescribed it was 25-44 years (43%). Sex distribution was similar for both drug groups, with about a third of the patients being men.
Depression was the most common problem for which TCAs and SSRIs were prescribed in 1998-99, although the proportion of TCAs prescribed for depression (48.8% [95% CI, 44.3%-53.3%]) was lower than that of SSRIs (81.9% [95% CI, 79.7%- 84.1%]). Other specific problems managed with TCAs were sleep disturbance (7%), anxiety (5%) and back complaints (4.5%). For the SSRIs, these were anxiety (5.8%) and phobia/compulsive disorder (1.7%).
When used for depressive disorders, TCAs had a prescribed daily dose consistently lower than the WHO DDD. The prescribed daily doses and DDDs for the most commonly dispensed TCAs were amitriptyline (mean, 59 mg; median, 50 mg; DDD, 75 mg), doxepin (mean, 61 mg; median, 50 mg; DDD, 100 mg) and dothiepin (mean, 85 mg; median, 75 mg; DDD, 150 mg). The prescribed daily doses for the most commonly dispensed SSRIs were much closer to the DDD: fluoxetine (mean, 24 mg; median, 20 mg; DDD, 20 mg), paroxetine (mean, 23 mg; median, 20 mg; DDD, 20 mg) and sertraline (mean, 72 mg; median, 50 mg; DDD, 50 mg).
Community health surveys
The 1997 National Mental Health and Wellbeing Profile of Adults identified a 5.8% prevalence of affective disorders (depression, 5.1%; dysthymia, 1.1%) during the 12 months before the survey among people aged 18 years or over.10 Women were more likely than men to have experienced affective disorders (7.4% compared with 4.2%).
Although based on self-reports, household surveys conducted by the Australian Bureau of Statistics in 1989-90 and 1995 identified marked changes in the number of people reporting current or previous depression. In the 1995 National Health Survey, 8.1 persons per 1000 population reported depression as a long term condition, compared with 2.8 persons per 1000 in the 1989-90 survey. For depression as a recent illness, 11.4 per 1000 population reported this in 1995, compared with 5.8 per 1000 in 1989-90.8,9