Neural Representations of Death-Related Concepts Identify Conceptual Alteration of Self in Suicidal Youth

The understanding of suicidal ideation would be significantly enhanced by a biologically based measure that can meaningfully inform about the nature of the underlying neurocognitive alteration, as well as objectively identify individuals experiencing suicidal thoughts. Here we report on such an approach that assesses alterations in the neural representations of concepts related to death in people who engage in suicidal ideation. Young healthy control participants and participants with Suicidal Ideation thought about the meaning of 28 stimulus concepts, among them concepts referring to death or suicide, while their brain activity was assessed using fMRI. Their brain activity was analyzed using a machine-learning algorithm (Gaussian Naïve Bayes) to distinguish the two groups, based on their brain activity in brain regions previously found to be related to thinking about oneself. The classifier distinguished the two groups with moderate but reliable accuracy, based on alterations in the fMRI signatures of the self-representation when they thought about death-related concepts. The study establishes a biological, neurocognitive basis that identifies meaningful alterations in psychological representations in participants with suicidal ideation.