Habitual starvation and provocative behaviors: two potential routes to extreme suicidal behavior in anorexia nervosa

Can the Phenomenology of a Suicidal Crisis Be Usefully Understood As a Suite of Antipredator Defensive Reactions?

When perceiving a dangerous predation threat, mammalian and other species activate antipredator defensive reactions. These include the seemingly paradoxical-but compatible-activation of overarousal (e.g., agitation, insomnia) and "shutdown" (e.g., mutism, withdrawal) states. Acute suicidal crises, too, are characterized by the co-occurrence of overarousal and shutdown behaviors. In the minutes, hours, and days prior to one's death by suicide, it is not uncommon for one to be simultaneously agitated and socially withdrawn, states that resemble antipredator defensive reactions. In this article, we present empirical, clinical, and philosophical grist for our conjecture that antipredator defensive reactions may serve as a useful way to understand the phenomenology of a serious suicidal crisis, and we reflect on the implications that soon-to-be suicide decedents are simultaneously killer and victim.

The interpersonal theory of suicide and adolescent suicidal behavior

BACKGROUND

Joiner's interpersonal theory of suicide (IPTS) proposes that suicide results from the combination of a perception of burdening others, social alienation, and the capability for self-harm. The theory gained some empirical support, however the overall model has yet to be tested. This study aimed to test the main predictions of IPTS in a large community sample of Israeli adolescents.

METHOD

1196 Israeli Jewish and Arab high-school pupils participating in the SEYLE project completed a self-report questionnaire measuring perceived burdensomeness, thwarted belongingness, health risk behaviors, and non-suicidal self-injury (risk variables), and suicidal ideation and suicide attempts (outcome measures). The data were tested in cross-sectional regression models.

RESULTS

Consistent with IPTS, perceived burdensomeness was found to interact with thwarted belongingness, predicting suicidal ideation. Depression mediated most of the effect of thwarted belongingness and perceived burdensomeness on suicidal ideation. Acquired capability for self-harm, as measured by health risk behaviors and direct non-suicidal self-injurious behaviors, predicted suicide attempt. However, this mechanism operated independently from ideation rather than in interaction with it, at variance with IPTS-based predictions.

LIMITATIONS

The cross-sectional design precludes conclusions about causality and directionality. Proxy measures were used to test the interpersonal theory constructs.

CONCLUSION

The findings support some of the IPTS predictions but not all, and imply two separate pathways for suicidal behavior in adolescents: one related to internalizing psychopathology and the other to self-harm behaviors. This conceptualization has clinical implications for the differential identification of adolescents at risk for suicidal behavior and for the development of prevention strategies.

A perfect storm: examining the synergistic effects of negative and positive emotional instability on promoting weight loss activities in anorexia nervosa

Growing evidence indicates that both positive and negative emotion potentially influence the development and maintenance of anorexia nervosa, through both positive and negative reinforcement of weight loss activities. Such reactive emotional experience may be characterized by frequent and intense fluctuations in emotion, a construct known as "emotional instability." The purpose of this study was to investigate the association between positive emotional instability and weight loss activities in anorexia nervosa, and to investigate the synergistic effects of positive and negative emotional instability on promoting weight loss activities. Using ecological momentary assessment methods, 118 participants with anorexia nervosa reported their emotional experiences and behaviors at least six times daily over 2 weeks using a portable digital device. Using generalized linear modeling, results indicated that high levels of both positive and negative emotional instability, and the interaction between the two, were associated with more frequent weight-loss activities, beyond anorexia subtype and mean levels of emotional intensity. These findings indicate that when women with anorexia exhibit both high levels of both positive and negative emotional instability they are more prone to a variety of weight loss activities. The importance of addressing the role of both positive and negative emotion in anorexia treatment is discussed.

The joint influence of acquired capability for suicide and stoicism on over-exercise among women

We investigated longitudinal relationships among eating disorder behaviors, stoicism, and the acquired capability for suicide (ACS), which is a construct comprised of pain tolerance and fearlessness about death. University students (n=150) completed assessments measuring stoicism, ACS, and eating disorder behaviors at two time points approximately 30days apart. Among women, there was a quadratic relationship between ACS and over-exercise behaviors, such that as ACS increased the positive association between ACS and over-exercise became more pronounced. Further, among women, ACS moderated the relationship between stoicism and over-exercise, such that high levels of ACS in combination with stoicism predicted increases in over-exercise. Results suggest that ACS in combination with stoicism may lead women to engage in more eating disordered behaviors, like over-exercise.

Fasting and acquired capability for suicide: a test of the interpersonal-psychological theory of suicide in an undergraduate sample

Though some preliminary research within the framework of the interpersonal-psychological theory of suicide (IPTS; Joiner, 2005) has postulated that restrictive eating may contribute to increased risk for suicide through its effect on the acquired capability for suicide (ACS; i.e., increased fearlessness about death and heightened physical pain tolerance), existing studies have not conducted direct tests of this relationship. To enhance understanding of this relationship, we compared undergraduates who endorsed one form of restrictive eating, fasting, (n = 99) to controls endorsing no forms of eating pathology over the lifetime (n = 94). We hypothesized that the fasting group would have higher ACS and higher likelihood of suicide attempt history. Contrary to hypotheses, no differences emerged between groups on ACS, and frequency of fasting within the fasting group was not significantly associated with ACS. Consistent with hypotheses, the fasting group was more likely to have suicide attempt history. Though results were not entirely consistent with hypotheses, the current study represents the first attempt at isolating and examining one form of restrictive eating (i.e., fasting) within the context of the IPTS. Results suggest that, in isolation, fasting may not be directly contributing to increases in ACS.

Temporal associations between disordered eating and nonsuicidal self-injury: examining symptom overlap over 1 year

Disordered eating (DE) and nonsuicidal self-injury (NSSI) commonly co-occur. This study compared several models of the longitudinal relationship between DE and NSSI, including concurrent and prospective models, and examined the possible moderating roles of self-objectification, impulsivity, and emotion dysregulation in these relationships. Individuals with NSSI (N=197) recruited from online forums completed measures of NSSI and DE every 3 months for 1 year. We tested the associations between NSSI and DE using hierarchical linear models. Results supported a concurrent relationship, wherein frequency of NSSI positively covaried with concurrent DE severity. Body surveillance moderated the concurrent relationship between NSSI and DE. Individuals who engaged in more body surveillance endorsed high levels of DE pathology, whereas those lower in body surveillance engaged in more frequent NSSI only at higher levels of DE. In addition, whereas DE did not prospectively predict NSSI, frequency of NSSI predicted more severe DE 3 months later. The prospective relationship between DE and later NSSI was moderated by emotion dysregulation, such that highly dysregulated individuals had a stronger relationship between DE and later NSSI, whereas this relationship was not significant among individuals low in emotion dysregulation. These findings add valuable information regarding the co-occurrence of self-damaging behaviors.

Restraint feeds stress: The relationship between eating disorder symptoms, stress generation, and the interpersonal theory of suicide

Integrating research on stress generation and the interpersonal theory of suicide we examined whether eating disorder symptoms are related to stress generation and whether negative life events (stressors) contribute to feelings of burdensomeness and low belongingness. At two time points (approximately 1month apart), participants (n=186; 75% female) completed questionnaires measuring eating disorder symptoms, negative life events, burdensomeness, and belongingness. Regression analyses indicated that while controlling for depression, anxiety, and baseline frequency of negative events, dietary restraint significantly predicted negative events at follow-up. Dietary restraint indirectly influenced higher levels of perceived burdensomeness and low belongingness through its influence on negative events. Thus, dietary restraint may contribute to stress generation, and in turn exacerbate feelings of burdensomeness and low belongingness, two important constructs of the interpersonal theory of suicide. Greater understanding of these factors could lead to more effective and targeted suicide interventions for individuals who restrict food intake.

Nothing Tastes as Good as Thin Feels: Low Positive Emotion Differentiation and Weight Loss Activities in Anorexia Nervosa

Positive emotion (PE) has not been well studied in anorexia nervosa. Low positive emotion differentiation (PED), which involves a diminished ability to distinguish between discrete positive emotions, may contribute to positive emotion dysregulation in anorexia. Specifically, low PED may interact with elevated PE intensity to both motivate and reinforce weight loss and evaluation behaviors. Using ecological momentary assessment, we examined PE and weight loss behaviors reported over two weeks. As hypothesized, low PED predicted more vomiting, laxative-use, exercising, weighing, checking for fat, and restricting. Furthermore, those with low PED who experienced elevated average PE intensity reported even more frequent behaviors. Within-person analyses indicated that, for those with low PED, more weight loss behaviors at one recording predicted elevated PE at the subsequent recording. Similarly, for those with low PED higher momentary PE predicted more subsequent weight loss behaviors. Thus, low PED in anorexia may reinforce and motivate weight loss behavior.

The current status of suicide and self-injury in eating disorders: a narrative review

The aim of this paper is to review recent literature on suicide and self-injury in eating disorders (ED) including anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Among psychiatric diagnoses, EDs are associated with increased mortality rates, even when specialized treatment is available. Of the mortalities that are reported in individuals with EDs, suicide is among the most commonly reported causes of death. Additionally, suicidal and non-suicidal self-injurious behaviors occur frequently in this clinical population. A literature search was undertaken using the databases of Medline/PubMed and PsycInfo to identify papers describing suicidality in individuals with ED diagnoses. The authors identified studies and review articles published between 2005-2013 (inclusive) that describe the relationship between EDs and suicide, and associated behaviors including self-injurious behaviors, or non-suicidal self-injury (NSSI). The initial search resulted in 1095 papers that met the a priori search criteria. After careful review, 66 papers were included. The majority of papers described clinical cohorts that were studied longitudinally. The diagnosis described most frequently in selected studies was AN. There are limited current data about the prevalence of suicide and NSSI among individuals with EDs. Among the published studies that focus specifically on the relationship between EDs and suicidality, most describe AN in more detail than other EDs. Nonetheless, rates of mortality, and specifically rates of suicide, are undeniably high in ED populations, as are the rates of self-harm. Therefore, it is critical for clinicians and caretakers to carefully evaluate these patients for suicide risk and to refer promptly for appropriate treatment.

Psychological models of suicide

Suicidal behavior is highly complex and multifaceted. Consequent to the pioneering work of Durkheim and Freud, theoreticians have attempted to explain the biological, social, and psychological nature of suicide. The present work presents an overview and critical discussion of the most influential theoretical models of the psychological mechanisms underlying the development of suicidal behavior. All have been tested to varying degrees and have important implications for the development of therapeutic and preventive interventions. Broader and more in-depth approaches are still needed to further our understanding of suicidal phenomena.

Aberrant pain perception in direct and indirect non-suicidal self-injury: an empirical test of Joiner's interpersonal theory

Using a community sample (N=148) we examined pressure pain perception in 3 study groups--people who engaged in non-suicidal self-injury, people who engaged in indirect forms of self-injury, and non-self-injuring controls. In so doing we tested hypotheses derived from Joiner's (2005) interpersonal theory of suicide. Consistent with previous studies and with Joiner's model, people who engaged in NSSI endured pain for significantly longer than non-self-injuring controls. Importantly, pain endurance in the Indirect self-injury group was comparable to that found in the NSSI group and significantly elevated relative to controls. This pattern of results suggests that abnormal pain perception may not be specific to forms of self-injury (e.g., NSSI) that involve immediate physical pain (e.g., cutting). Our findings further suggest that the concept of acquired capability for suicide might have relevance for both direct and indirect forms of self-injurious behavior.

Exercise caution: over-exercise is associated with suicidality among individuals with disordered eating

We conducted four studies to examine the relationship between over-exercise and suicidality. Study 1 investigated whether over-exercise predicted suicidal behavior after controlling for other eating disorder behaviors in a patient sample of 204 women (144 with Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) Bulimia Nervosa [BN]). Study 2 tested the prospective association between over-exercise and acquired capability for suicide (ACS) in a sample of 171 college students followed for 3-4 weeks. Study 3 investigated whether pain insensitivity accounted for the relationship between over-exercise and ACS in a new sample of 467 college students. Study 4 tested whether ACS accounted for the relationship between over-exercise and suicidal behavior in a sample of 512 college students. In Study 1, after controlling for key covariates, over-exercise was the only disordered eating variable that maintained a significant relationship with suicidal behavior. In Study 2, Time 1 over-exercise was the only disordered eating behavior that was associated with Time 2 ACS. In Study 3, pain insensitivity accounted for the relationship between over-exercise and ACS. In Study 4, ACS accounted for the relationship between over-exercise and suicidal behavior. Over-exercise appears to be associated with suicidal behavior, an association accounted for by pain insensitivity and the acquired capability for suicide; notably, this association was found across a series of four studies with different populations.

The relationship between body dysmorphic disorder behaviors and the acquired capability for suicide

In a sample of 200 individuals diagnosed with body dysmorphic disorder (BDD), we utilized the interpersonal-psychological theory for suicide as a framework to examine BDD behaviors that might be associated with suicide risk, insofar as they might increase the acquired capability for suicide. We predicted that physically painful BDD behaviors (e.g., cosmetic surgery, restrictive eating) would be associated with suicide attempts but not suicide-related ideation because these behaviors increase capability for, but not thoughts about, suicide. Our hypothesis was partially confirmed, as BDD-related restrictive food intake was associated with suicide attempts (but not suicide-related ideation) even after controlling for numerous covariates.

Characteristics of suicide attempts in anorexia and bulimia nervosa: a case-control study

Objective

Compared to other eating disorders, anorexia nervosa (AN) has the highest rates of completed suicide whereas suicide attempt rates are similar or lower than in bulimia nervosa (BN). Attempted suicide is a key predictor of suicide, thus this mismatch is intriguing. We sought to explore whether the clinical characteristics of suicidal acts differ between suicide attempters with AN, BN or without an eating disorders (ED).

Method

Case-control study in a cohort of suicide attempters (n = 1563). Forty-four patients with AN and 71 with BN were compared with 235 non-ED attempters matched for sex, age and education, using interview measures of suicidal intent and severity.

Results

AN patients were more likely to have made a serious attempt (OR = 3.4, 95% CI 1.4–7.9), with a higher expectation of dying (OR = 3.7,95% CI 1.1–13.5), and an increased risk of severity (OR = 3.4,95% CI 1.2–9.6). BN patients did not differ from the control group. Clinical markers of the severity of ED were associated with the seriousness of the attempt.

Conclusion

There are distinct features of suicide attempts in AN. This may explain the higher suicide rates in AN. Higher completed suicide rates in AN may be partially explained by AN patients' higher desire to die and their more severe and lethal attempts.