DSM-IV generalized anxiety disorder in the Australian National Survey of Mental Health and Well-Being.

BACKGROUND: This paper reports population data on DSM-IV generalized anxiety disorder from the Australian National Survey of Mental Health and Well-Being.

METHODS: The data were obtained from a nationwide household survey of adults using a stratified multi-stage sampling process. A response rate of 78.1% resulted in 10,641 persons being interviewed. Diagnoses were made using the Composite International Diagnostic Interview. The interview was computerized and conducted by trained lay interviewers.

RESULTS: Prevalence in the total sample was 2.8% for 1-month GAD and 36% for 12-month GAD. Persons over 55 years of age were less likely to have GAD than those in the younger age groups. Logistic regression analysis also showed that a diagnosis of GAD was significantly associated with being of younger to middle age, being separated divorced or widowed, not having tertiary qualifications or being unemployed. Co-morbidity with another affective, anxiety, substance use or personality disorders was common, affecting 68% of the sample with 1-month DSM-IV GAD. GAD was associated with significant disablement, and 57% of the sample with DSM-IV GAD had consulted a health professional for a mental health problem in the prior 12 months.

CONCLUSIONS: The survey provides population data on DSM-IV GAD and its correlates. GAD is a common disorder that is accompanied by significant morbidity and high rates of co-morbidity with affective and anxiety disorders, and is associated with marital status, education, employment status, but not sex. Changes to DSM-IV diagnostic criteria did not appear to affect the prevalence rate compared to previous population surveys.