Prevalence and correlates of DSM-IV major depression in an Australian national survey

Abstract

Background: Community surveys have reported prevalence of depressive disorders in adult populations since the 1970s. Until recently, no epidemiological studies of the same magnitude have been conducted to provide a profile of the adult population in Australia. This study examines the current (30-day) prevalence and correlates of major depression in the adult Australian population using data from the National Survey of Mental Health and Well-being, and compares the results with other national studies.

Methods: Data were derived from a national sample of 10,641 people 18-75+ years of age surveyed using the computerised version of the Composite International Diagnostic Interview Version 2.1.

Results: The overall weighted prevalence of current (30-day) major depression was 3.2% with the highest rate (5.2%) being found in females in mid life. This rate is between those of the USA National Comorbidity Survey and the Epidemiological Catchment Area study, and similar to the British Psychiatric Morbidity Survey. The strongest correlates for reported current major depression include being unemployed, smoking, having a medical condition, followed by being in mid life, previously married, and female. Living with a partner and drinking 1 to 2 glasses of alcohol per day were least correlated. Some correlates of major depression relate to social disadvantage and lifestyle issues.

Limitations: The study design does not allow definition of direction of causality.

Conclusion: Lowering the prevalence rate of major depression will require close attention to public health approaches to address the relationships between smoking, social isolation, poor health, mood and physical well-being. The best focus for this approach may be primary care settings.