Detecting suicidal intent in the unconscious mind

The Situationist has just alerted me to a fantastic article in the Boston Globe on the development a cognitive test for suicidal thoughts that doesn’t rely solely on the conscious mind.

The test is a variant of the Implicit Association Test (IAT) that has been used to look at our automatic associations between different concepts, based on how quickly we can categorise them.

We’ve discussed in it more detail previously but it essentially relies on the fact that if you have an pre-existing association between two concepts, say, the concepts ‘blonde’ and ‘stupid’, making similar associations will be faster than associating ‘blonde’ and ‘clever’ because you’re going to be quicker doing whichever classification best matches associations you already have.

Most of the research has been done on implicit social biases, finding that even people who have no explicit prejudices against blondes, foreigners, men or whomever, might find they automatically associate certain negative concepts with these groups.

However, as the test purely measures associations between concepts, it can be used to look for other implicit biases. In fact, the researchers featured in the Globe piece have used it to test for implicit associations between the concept of self and suicide.

Most suicidal patients will admit they are at risk of harming themselves. Contrary to popular belief, suicidal patients don’t necessarily want to die, they just want the pain to stop and will be upfront if they think professionals can help.

Some, however, may have decided that death is the only relief, or they may be unable to see clear alternatives owing to the effects of mental illness on thinking.

Suicide risk is assessed on the basis of people’s actions and what they say, so a completely determined person can talk their way through a risk assessment.

This new research is testing the IAT as a way of assessing suicide risk, even if the person is denying they are suicidal.

The study, led by Dr. Matthew Nock, an associate professor in the psychology department at Harvard University, is called the Suicide Implicit Association Test…

But critics question whether the test is actually practical, and up until now no one has tried to apply it to suicide prevention. As part of his training, Nock worked extensively with adolescent self-injurers – self-injury, such as cutting and burning, is an important coping method for those who engage in it, though they are often unlikely to acknowledge it. Nock thought that the IAT could serve as a behavioral measure of who is a self-injurer and whether such a person was in danger of continuing the behavior, even after treatment.

In their first major study, Nock and Banaji asserted that the IAT could be adapted to show who was inclined to be self-injurious and who was not. And more important, they said, the test could reveal who was in danger of future self-injury.

It’s an interesting idea and the early results look intriguing, although as the article notes, the proof will be how well it actually works in practice.

One difficulty with risk assessment in psychiatry is its almost impossible to do ‘ideal’ outcome studies because of the ethical implications.

For example, lets say your new risk measure predicts someone will kill themselves. From a statistical point of view, you’d want to wait and see if they do, so you can compare these positive predictions with the negative predictions and get an accuracy measure.

But from a purely humane point of view, you’re going to intervene and try and help the person, meaning risk assessments are not always based on ‘ideal’ statistical information.

The article has an excellent discussion of some of the wider ethical and practical issues involved, drawing on the writers own experience of his brother’s suicide.

Link to Boston Globe article ‘On the Edge’ (via The Situationist).