Patterns of hospitalisation for depressive and anxiety disorders across the lifespan in Australia

Background: Hospitalisation rates for anxiety and depressive disorders vary with age and sex but there are few detailed analyses. Methods: Specialist psychiatric hospital separation data compiled by the Australian Institute of Health and Welfare in the National Hospital Morbidity Database from 1998/99-2004/5 were analysed for the principal psychiatric diagnoses of depressive disorders and neurotic, stress related and somatoform disorders. Separation rates were calculated by age, year and sex using population data linearly extrapolated from Australian censuses. Results: The average annual rate of specialised psychiatric separations for all depressive disorders was 2.61 per 1000 for men, 4.77 for women. The highest separation rates for depression occurred in men aged 75-79 years. Severe depression without psychosis separations peaked in women in midlife. Psychotic depression separations peaked in late life. The average annual rate of separations for neurotic, stress related and somatoform disorder was 2.08 per 1000 for men, 1.96 for women. In women rates declined with age but in men rates peaked between ages 50 and 60 years due to PTSD. The average length of stay for depressive and anxiety disorders increased with age. Limitations: Accuracy of data collection by clinicians and coding by medical records staff is unknown. Conclusions: Planning for hospital services should take into account that separation rates for depressive and anxiety disorders vary with age, sex and type of disorder. (C) 2008 Elsevier B.V. All rights reserved.