Structural brain alterations associated with suicidal thoughts and behaviors in young people: results from 21 international studies from the ENIGMA Suicidal Thoughts and Behaviours consortium

Research led by Associate Professor Lianne Schmaal, with 78 co-authors

Published 7 September 2022

Context

High rates of suicide among young people are of concern and understanding of the factors and mechanisms underlying suicidal thoughts and behaviours in young people is needed. One way of doing this is through neuroimaging studies to identify whether any biological risk markers or indicators exist. Few previously published studies have focused on youth and studies often involved small sample sizes.

Research and findings

The research involved pooling data from 21 magnetic resonance imaging (MRI) studies across 10 countries, as part of the ENIGMA Suicidal Thoughts and Behaviours consortium. This enabled the examination of associations between brain structure and suicidal thoughts and behaviours in young people aged 8-25 years.

In a ‘homogeneous sample’ of 577 young people with mood disorders (either major depressive disorder or bipolar disorder) suicidal thoughts and behaviours were measured by the Columbia Suicide Severity Rating Scale, a well-validated and widely-established instrument. The surface area of the frontal pole (see image below) was found to be lower in young people with mood disorders and a history of suicide attempts than those without a lifetime of suicide attempt. No associations with suicidal ideation were found.

In heterogeneous samples using different instruments to identify suicidal thoughts and behaviours, and including young people with various diagnosed mood disorders, no significant associations in brain structure were observed.

Implications

The frontal pole is the part of the brain that is associated with higher-order functions involved in emotion and other behavioural regulation such as decision-making, cognitive inhibition and relating information about the world to oneself. Differences in brain structure provide some insight into the underlying mechanisms of suicidal behaviours and may eventually provide important targets for suicide prevention strategies.

However, further research is needed to understand the nature of the relationship to suicide risk, and how brain structure might interact with many other social, psychological and cognitive risk factors.