Interoception Moderates the Association Between Reward Sensitivity and Suicide Attempt History in Patients with Anorexia Nervosa

Suicide is a leading cause of death for people with anorexia nervosa, a severe eating disorder characterized by extreme restriction of food and a distorted view of one's body. While doctors know the risk is high, the specific reasons why some individuals with this illness attempt suicide while others do not remain unclear. To understand this, researchers have begun looking at two distinct ways the brain processes information. The first is how a person senses their own internal body signals, such as hunger, fullness, or emotional tension; scientists call this interoception. The second is how the brain responds to rewarding experiences, or the drive to seek out things that feel good. These two systems are deeply connected, yet it has been unknown how they might work together to influence the risk of suicidal behavior in people with anorexia.

A team of researchers in France set out to explore this connection by studying 160 patients diagnosed with anorexia nervosa. The group was predominantly female, with an average age of 26. The scientists asked the participants to complete detailed questionnaires about their history of suicide attempts, their ability to recognize their own bodily feelings, and their sensitivity to rewards. They also gathered information on other factors that could influence the results, such as how long the patients had been ill, their history of childhood trauma, and whether they had other mental health conditions. The goal was to see if the relationship between reward sensitivity and suicide risk changed depending on how well a person could perceive their own internal states.

The study found that 22 percent of the patients, or 34 individuals, had a history of at least one suicide attempt. When the researchers analyzed the data, they discovered that both a lack of awareness of bodily feelings and a high sensitivity to rewards were individually linked to a history of suicide attempts in initial analyses. However, the most significant finding was how these two factors interacted. The data showed that high reward sensitivity predicted a history of suicide attempts only in patients who still had a relatively clear ability to sense their internal body signals. For patients who had significant deficits in sensing their bodily states, being highly sensitive to rewards did not appear to be linked to a history of suicide attempts. In other words, the drive toward rewarding experiences seemed to increase the risk of suicidal behavior specifically when the person's internal body awareness remained intact.

This interaction held true even after the researchers adjusted for other serious factors, such as the length of time the patient had suffered from the disorder, the severity of their eating disorder symptoms, and the presence of childhood trauma. In these adjusted models, the individual links between reward sensitivity or body awareness deficits and suicide attempts were no longer statistically significant on their own; instead, the specific combination of these factors remained the key predictor. The study also confirmed that longer illness duration and more severe childhood trauma were independently associated with a higher likelihood of having attempted suicide. The researchers suggest that for some patients, the combination of being able to feel their internal states clearly while also being highly driven by rewards might create a specific vulnerability. In these individuals, maladaptive behaviors, such as self-harm or suicide attempts, might become reinforced because they provide a temporary sense of relief or reward that the brain learns to seek out.

The authors emphasize that because this study looked back at past events rather than following patients over time, it cannot prove that these factors cause suicide attempts. It is also possible that the specific way the researchers measured body awareness captured a mix of different experiences, such as both healthy attention to the body and anxious hypervigilance. Despite these limitations, the findings offer a new perspective on suicide risk in anorexia. Instead of viewing risk factors in isolation, the study suggests that clinicians might benefit from considering how a patient's ability to sense their body interacts with their drive for rewards. This approach could help identify specific subgroups of patients who might need different types of support, moving toward a more personalized understanding of who is most at risk and why.