Suicidal Behaviour in Te Rau Hinengaro: The New Zealand Mental Health Survey

OBJECTIVE: To describe prevalence and correlates of suicidal behaviour in the New Zealand population aged 16 years and over. METHOD: Data are from Te Rau Hinengaro: The New Zealand Mental Health Survey, a nationally representative household survey conducted from October 2003 to December 2004 in a sample of 12,992 participants aged 16 years and over to study prevalences and correlates of mental disorders assessed using the World Mental Health Composite International Diagnostic Interview. Lifetime and 12 month prevalences and onset distributions for suicidal ideation, plans and attempts, and sociodemographic and mental disorder correlates of these behaviours were examined. RESULTS: Lifetime prevalences were 15.7% for suicidal ideation, 5.5% for suicide plan and 4.5% for suicide attempt, and were consistently significantly higher in females than in males. Twelve-month prevalences were 3.2% for ideation, 1.0% for plan and 0.4% for attempt. Risk of ideation in the past 12 months was higher in females, younger people, people with lower educational qualifications, and people with low household income. Risk of making a plan or attempt was higher in younger people and in people with low household income. After adjustment for sociodemographic factors, there were no ethnic differences in ideation, although Māori and Pacific people had elevated risks of plans and attempts compared with non-Māori non-Pacific people. Individuals with a mental disorder had elevated risks of ideation (11.8%), plan (4.1%) and attempt (1.6%) compared with those without mental disorder. Risks of suicidal ideation, plan and attempt were associated with mood disorder, substance use disorder and anxiety disorder. Major depression was the specific disorder most strongly associated with suicidal ideation, plan and attempt. Less than half of those who reported suicidal behaviours within the past 12 months had made visits to health professionals within that period. Less than one-third of those who had made attempts had received treatment from a psychiatrist. CONCLUSIONS: Risks of making a suicide plan or attempt were associated with mental disorder and sociodemographic disadvantage. Most people with suicidal behaviours had not seen a health professional for mental health problems during the time that they were suicidal.