Suicide attempters have a reduced capacity for social perception in areas of the brain that have been implicated in pain tolerance and social cognition, according to a study recently published in Scientific Reports.

As human beings, we have an innate desire for social inclusion, and when this is not fulfilled it can have severe consequences on our mental well-being. Lack of social inclusion has previously been reported as a risk factor for suicide. In many cases suicide victims had experienced at least one negative life event, which was perceived as a form of social exclusion e.g. relationship breakdown or job loss in the final few months before their death.

However, these events are relatively common and in the majority of cases they do not lead to suicide, suggesting that only some people are at an increased risk of suicide when faced with these stressful life events. The key to understanding why some people are more vulnerable to suicide in times of social distress is thought to come from understanding the way these individuals process social perception.

Previous studies have found people who are vulnerable to suicidal behaviour have deficits in several brain regions and cognitive processes. For example, suicide attempters demonstrated increased activation of the lateral orbitofrontal cortex when they were shown angry faces which suggests they over evaluate negative cues.

The current study lead by Emilie Olié (Montpellier University) used MRI to investigate the neural processing of social rejection in suicide attempters. For the research, 36 women with a history of depression but no suicide attempt, 41 women with a history of depression and suicide attempts and 28 healthy controls took part in a ‘Cyberball Game’ which acted as a paradigm for social exclusion. During the task each participant played a virtual ball game from which they were gradually excluded.

It was found that both groups with a history of depression reported higher levels of task-related social distress, compared to the control group. Additionally, suicide attempters showed decreased brain activation to social exclusion in the left insula and supramarginal gyrus, which have been implicated in pain tolerance and social cognition.

“Our results suggest a role for the left posterior insula and parietal regions in sensitivity to social exclusion as part of the suicidal vulnerability in women, and raise the question of the role of social perception and physical pain in the suicidal process,” the researchers concluded.

The findings are in agreement with previous research which has reported structural and connectivity abnormalities of the insula as a risk factor for suicide. Overall, the current study suggests that suicide attempters have prolonged brain deficits related to social perception, and this may play a role in the decision to end their own life.