Background: Autistic people with co-occurring attention deficit/hyperactivity disorder (ADHD) appear to be at heightened risk of suicide. To understand why, we explored two explanatory mechanisms from the interpersonal theory of suicide: first, that co-occurring ADHD might be associated with greater risk through greater thwarted belongingness and perceived burdensomeness and, secondly, that hyperactive/impulsive features might incur additional risk through their association with painful and provocative events, which are suggested to create "capability" for suicide.
Methods: Autistic adults (n = 314) completed an online survey including measures of thwarted belongingness, perceived burdensomeness, painful and provocative events, acquired capability for suicide, and ADHD features. Creating an overall index of likely ADHD, we examined associations between likely ADHD, suicide ideation, and lifetime suicide attempts through the parallel mediators of thwarted belongingness, perceived burdensomeness, anxiety, and depression. In several models, we then examined hyperactive, impulsive, and inattentive features as predictors of exposure to painful and provocative events and subsequent capability for suicide, and examined whether these two variables, sequentially or individually, mediated an association with lifetime suicide attempts.
Results: Likely ADHD was associated with past-year suicide ideation through greater depression and perceived burdensomeness, which also mediated its association with more suicide attempts. Hyperactive and impulsive features were associated with exposure to painful and provocative events and through this acquired suicide capability. Both features were associated with more numerous suicide attempts through these two mediators sequentially, and through exposure to painful and provocative events alone.
Conclusions: These data suggest that suicidality in autistic people with ADHD may be partially related to perceived burdensomeness and to acquired suicide capability after exposure to painful and provocative events. However, as we observed a pathway to suicidality associated with painful and provocative events alone, it is likely that there are also other explanatory mechanisms for the influence of traumatic events on suicide risk.
Keywords: ADHD; acquired capability; perceived burdensomeness; suicide; thwarted belongingness.
Why is this an important issue?: Suicide is a leading cause of premature death in autistic people, but we still know little about why autistic people are at greater risk and how we can help. Recent findings suggest that autistic people with co-occurring attention deficit/hyperactivity disorder (ADHD) are at even higher risk, but we do not yet understand why.
What was the purpose of this study?: This research examined two potential explanations for higher risk of suicide in autistic people with co-occurring ADHD. First, we expected that because these individuals are often very isolated and struggle with independence and employment, they might be more vulnerable to two risk factors for suicide: “thwarted belongingness,” the feeling of being alienated from other people, and “perceived burdensomeness,” the feeling that one is a burden to others. We also expected that hyperactive/impulsive features associated with ADHD might make people more likely to experience painful and dangerous events. Exposure to events like this is suggested to make people less frightened of dying by suicide and more able to attempt to end their lives. This is called “acquiring capability” for suicide.
What did the researchers do?: We asked 314 autistic adults to complete an online survey including measures of thwarted belongingness, perceived burdensomeness, exposure to painful and dangerous events, and acquired capability for suicide. They also completed a scale measuring ADHD features, and symptoms of depression and anxiety. We then looked at which of these factors, if any, explained suicide risk in autistic people with co-occurring ADHD.
What were the results of the study?: Our data suggest that autistic people with co-occurring ADHD might be at greater risk of suicide ideation and attempts because they are more likely to experience depression and to feel like a burden to others. We also found that people with high degrees of hyperactive/impulsive features were more likely to experience painful and dangerous events, and, therefore, had greater capability for suicide—because of this, they were more likely to have attempted suicide more times in the past. Exposure to these kinds of traumatic events also increased the risk of suicide all by itself.
What do these findings add to what was already known?: Very little is known about why autistic people with co-occurring ADHD might be at even higher risk of suicide than people with either ADHD or autism alone. No studies have examined explanations for suicide in this subgroup.
What are potential weaknesses in the study?: Because this study looked at a snapshot of participants' current states, we cannot be sure of the direction of relationships between variables. For example, it might be that experiences of surviving suicide attempts actually make people feel more depressed and more like a burden afterward, rather than these feelings being the risk factors that contributed to suicide attempts.
How will these findings help autistic adults now or in the future?: These findings indicate feelings and experiences that are relevant to suicide risk in autistic people with co-occurring ADHD, which might thus be important to target in interventions.
Copyright 2024, Mary Ann Liebert, Inc., publishers.