Disability in Te Rau Hinengaro: the New Zealand Mental Health Survey.

Objective: To show the disability associated with 1 month mental disorders and chronic physical conditions for the New Zealand population, controlling for comorbidity, age and sex.
Method: A nationally representative face-to-face household survey was carried out from October 2003 to December 2004 with 12,992 participants aged 16 years and over, achieving a response rate of 73.3%. Mental disorders were measured with the World Mental Health (WMH) Survey Initiative version of the Composite International Diagnostic Interview (CIDI 3.0). Disability was measured with the WMH Survey Initiative version of the World Health Organization Disability Assessment Schedule (WMH WHO-DAS) in the long-form subsample (n = 7435). Outcomes include five WMH WHO-DAS domain scores for those with 1 month mental disorders and with chronic physical conditions.
Results: Mood disorders were associated with more disability than anxiety or substance use disorders. Experiencing multiple mental disorders was associated with substantial role impairment. Mental disorders and chronic physical conditions were associated with similar degrees of disability on average. The combination of mental and physical disorders had additive effects on associated disability.
Conclusions: Mood disorders are disabling. The investigation of disability in relation to 1 month rather than 12 month disorders is likely to provide a clearer indication of the disability associated with mood disorders. Although some researchers have queried whether negative mood can lead to 'over-reporting' of disability, recent conceptualizations of disability provide a perspective which may ease such concerns. Comorbidity, of mental disorders or of mental and physical disorders, is disabling.