Examining Mortality after Brain injury: Estimating the Risk of Suicide

This study asks a critical question: does moderate to severe brain injury in childhood increase the risk of suicide?

An estimated 74,260 New Zealand youth aged 0–24 years are living with a moderate to severe brain injury. Brain injuries can result from external forces to the head such as falls or road accidents (traumatic brain injury)—or from non-traumatic causes such as brain infections, stroke, tumours, or lack of oxygen.

When brain injury occurs during childhood or adolescence, it can disrupt normal brain development. This means problems may not appear immediately but can emerge years later as the child grows. Research shows that brain injury increases the risk of mental health problems, including self-harm, a major risk factor for suicide.

New Zealand has one of the highest suicide rates in the world, and Māori and young people are disproportionately affected. Between 2015 and 2019, 655 young people aged 10–24 died by suicide.

Self-harm and suicide are preventable. However, we first need to understand whether brain injury contributes to later suicide risk, and which services—across health, mental health, disability, and education, young people interact with in the years before their death. These service points represent key opportunities for intervention.

Using whole-population data, this study fills a major gap by:

Tracking long-term suicide risk in children with brain injury compared to those without. Identifying how sociodemographic, injury, and health factors influence this risk. Examining service use patterns to identify opportunities for suicide prevention.