Cautious response to US research into prediction of risk
American research into the prediction of the risk of suicide in at-risk individuals has provoked a cautious response from Irish experts.
The study, published in Nature Human Behaviour, suggested calculating the risk of suicide could be substantially improved through brain scanning techniques such as functional magnetic resonance imaging (fMRI).
It also suggested that machines with artificial intelligence could pick up neural signs of suicide risk through brain-scan analysis.
“There is optimism in our field that this approach can be useful in the future, but we’re not there yet,” said Prof Gary Donohoe, School of Psychology, NUI Galway, who is also part of the team at the Neuroimaging and Cognitive Genomics Centre at NUIG working on an international research project to better predict the course of diseases such as schizophrenia.
“That will only happen when these kinds of analytical approaches can predict not just what diagnostic group you are currently in, but what group you are likely to belong to in the future.”
The researchers, led by Marcel Just, professor of psychology at Carnegie Mellon University in Pittsburgh, measured the response in people’s brains to words with negative connotations, such as death, as well as words such as good, which are considered positive.
The emotional reaction to such words was altered in the 17 people studied who had ideas of suicide, compared to 17 healthy individuals. “For example, death evokes more sadness and shame,” said Prof Just.
“Our technique has the capability of not only detecting that certain thoughts are altered in people with suicidal ideation, but it also provides information about the nature of the alteration. This information provides a target for treatment, which could aim to reduce or eliminate the alteration.”
Prof Just said his team used a machine learning algorithm (software designed to learn and get cleverer from experience) to identify people with suicidal ideas based on their fMRI scans.
The prediction of suicide risk is notoriously difficult. There would be great interest in any new technique that could reliably help clinicians to improve risk assessment in advance of discharging a patient, for example.
“This study does not add to the accuracy of risk assessment,” Brendan Kelly, professor of psychiatry at Trinity College Dublin, cautioned, “although it might point to a useful avenue”.
The assessment of the risk of suicide over the course of a lifetime varies between 0.5 per cent and 1.2 per cent, said Prof Kelly.
For a person in Ireland today who lives to be 90, the statistical risk of suicide is 0.93 per cent, he said. That figure rises significantly to 10-15 per cent for individuals who have major depression.
Prof Kelly sounded a further note of caution, saying the number of people that took part in the Carnegie Mellon study was very small.
The only way to definitively show that using fMRI, or other brain scanning techniques to predict suicide risk worked, would be to scan people’s brains, make a risk prediction, and follow them up to see whether they did, in fact, die by suicide, said Prof Kelly.