Prevalence of mental disorders among Māori in Te Rau Hinengaro: the New Zealand Mental Health Survey.

OBJECTIVE: To describe the prevalence of mental disorders (period prevalence across aggregated disorders, 12 month and lifetime prevalence) among Māori in Te Rau Hinengaro: The New Zealand Mental Health Survey.

METHOD: Te Rau Hinengaro: The New Zealand Mental Health Survey, undertaken between 2003 and 2004, was a nationally representative face-to-face household survey of 12,992 New Zealand adults aged 16 years and over, including 2,595 Māori. Ethnicity was measured using the 2001 New Zealand census ethnicity question. A fully structured diagnostic interview, the World Health Organization World Mental Health Survey Initiative version of the Composite International Diagnostic Interview (CIDI 3.0), was used to measure disorder. The overall response rate was 73.3%. This paper presents selected findings for the level and pattern of mental disorder prevalence among Māori.

RESULTS: Māori lifetime prevalence of any disorder was 50.7%, 12 month prevalence 29.5% and 1 month prevalence 18.3%. The most common 12 month disorders were anxiety (19.4%), mood (11.4%) and substance (8.6%) disorders and the most common lifetime disorders were anxiety (31.3%), substance (26.5%) and mood (24.3%) disorders. Levels of lifetime comorbidity were high with 12 month prevalence showing 16.4% of Māori with one disorder, 7.6% with two disorders and 5.5% with three or more disorders. Twelve-month disorders were more common in Māori females than in males (33.6%vs 24.8%) and in younger age groups: 16-24 years, 33.2%; 25-44 years, 32.9%; 45-64 years, 23.7%; and 65 years and over, 7.9%. Disorder prevalence was greatest among Māori with the lowest equivalized household income and least education. However, differences by urbanicity and region were not significant. Of Māori with any 12 month disorder, 29.6% had serious, 42.6% had moderate and 27.8% had mild disorders.

CONCLUSION: Mental disorders overall and specific disorder groups (anxiety, mood and substance) are common among Māori and measures of severity indicate that disorders have considerable health impact. Findings provide a platform for informing public health policy and health sector responses to meeting mental health needs of Māori.