Brooke A. Ammerman

Development and validation of empirically derived frequency criteria for NSSI disorder using exploratory data mining

Research suggesting nonsuicidal self-injury (NSSI) may belong in a distinct diagnostic category has led to the inclusion of NSSI disorder in the DSM–5 section for future study. There has been limited research, however, examining the validity of Criterion A (the frequency criterion). The current study aimed to examine the validity of the frequency criterion of NSSI disorder through the use of an exploratory data mining method, structural equation modeling trees, as a way to determine a NSSI frequency that optimally discriminates pathological NSSI from normative behavior among undergraduate students (n = 3,559), 428 who engaged in NSSI in the previous year. The model included psychopathology symptomology found to be comorbid with NSSI and cognitive-affective deficits commonly associated with NSSI. Results demonstrated a first split between individuals with 0 and 1 act of NSSI in the past year, as was expected. Among individuals with 1 or more previous acts, the optimal split was between those with 5 and 6 NSSI acts in the past year. Results from the current study suggest that individuals with 6 acts of NSSI in past year, compared with those with 5 acts or less, may represent a more severe group of self-injurers. These individuals reported higher levels of related psychopathology symptomology and cognitive-affective deficits, in addition to decreased quality of life. Findings have potential implications for the proposed frequency criteria of NSSI disorder and how pathological NSSI is characterized.

The relationship between non-suicidal self-injury and borderline personality disorder symptoms in a college sample

BackgroundNon-suicidal self-injury (NSSI) is a major concern in both clinical and non-clinical populations. It has been approximated that 65-80% of individuals with borderline personality disorder (BPD) engage in some form of NSSI. Despite such high co-morbidity, much still remains unknown about the relationship between NSSI and BPD symptomatology. The goal of the current study was to identify individual BPD symptoms and higher order BPD factors that increase one’s vulnerability of NSSI engagement among a college sample. It was hypothesized that the BPD factor of emotion dysregulation and the BPD symptoms of affect instability and intense anger/aggression would be associated with the presence and frequency of NSSI.MethodSeven hundred twenty four undergraduates (61.2% female) completed self-report measures of BPD symptomology and NSSI history.ResultsRegression analyses revealed that among the individual BPD symptoms, past suicidality, impulsivity, chronic emptiness, and identity disturbance were each significantly, positively associated with lifetime history of NSSI, whereas unstable relationships were negatively associated with lifetime history of NSSI. The BPD symptom associated with NSSI frequency was dissociation. Among the BPD factors, emotion dysregulation and disturbed relatedness were both associated with NSSI history, but only disturbed relatedness was associated with NSSI frequency.ConclusionFindings show partial support for the importance of emotion dysregulation in the relationship between NSSI and BPD symptomatology, but also suggest that the relationship may be more complex and not solely based on emotion dysregulation.

Subjective pain during NSSI as an active agent in suicide risk

Non-suicidal self-injury (NSSI) has been identified as a correlate and predictor of suicidal ideation and attempts. Given the high-rates of NSSI presence among adolescents and young adults, it is important to identify specific characteristics of NSSI that might place individuals who engage in this behavior at highest risk for suicidal behavior. NSSI is thought to increase the acquired capability for suicide via habituation to self-harm, though the NSSI characteristics most responsible for this relationship are unclear. The current study examined three characteristics of NSSI (frequency, number of methods, and subjective pain) that may help to elucidate this risk relationship. University students (N=997) with a history of NSSI completed measures assessing lifetime NSSI frequency, number of NSSI methods employed, and subjective experience of pain during NSSI, as well as suicide attempt (SA) history. Results indicated that NSSI frequency, number of NSSI methods, and subjective pain experienced during NSSI were each positively associated with SA history. Further, subjective pain experienced during NSSI moderated the relationship between NSSI frequency and SA history, such that the association between NSSI frequency and SA history was stronger for individuals who experienced lower levels of subjective pain.

Suicide risk characteristics among aborted, interrupted, and actual suicide attempters.

Few studies have investigated suicide risk characteristics associated with interrupted and aborted suicide attempts. The present study aimed to empirically examine whether assessing a history of interrupted and aborted suicide attempts is valuable when assessing suicide risk, given the relative lack of literature in this area to date. To inform this question, the current study examined differences in risk factors for suicidal behavior among individuals who have carried out a suicide attempt, individuals who report having a history of only interrupted and/or aborted suicide attempts, and non-attempter controls. Approximately 447 undergraduates (M=21.10 years; SD=4.16; 77.6% female) completed measures of carried out suicide attempts, interrupted suicide attempts, aborted suicide attempts, acquired capability for suicide, suicide likelihood, depressive symptoms, suicidal ideation, and non-suicidal self-injury. Results suggest that a faction of individuals endorse interrupted and/or aborted suicide attempts (8.7%), but do not endorse carried out suicide attempts, even in non-clinical samples. Furthermore, results suggest that there are few clinically meaningful differences between those with a history of carried out suicide attempts and interrupted/aborted suicide attempts, suggesting that individuals with a history of these lesser studied suicidal behaviors are an important group to target for suicide risk intervention.

Negative urgency and reward/punishment sensitivity in intermittent explosive disorder

UNLABELLED Intermittent explosive disorder (IED) is the sole psychiatric diagnosis in which affective aggression is the cardinal symptom. Previous research has been equivocal with regard to the relationship between IED and impulsivity. This inconsistency may reflect the varied facets of impulsivity, with some aspects of impulsivity (e.g. negative urgency) as well as some overlapping, albeit distinct constructs (e.g. reward and punishment sensitivity) yet to be studied. METHODS The present study compared individuals diagnosed with IED (n=81) with psychiatric controls (PCs; n=52) and healthy volunteers (HVs; n=58) on the impulsivity domains of negative and positive urgency, perseverance, sensation seeking, and premeditation, as well as on reward and punishment sensitivity. We hypothesized that individuals with IED would show greater negative and positive urgency, reward sensitivity, punishment sensitivity, with negative urgency independently predicting IED status. We also hypothesized that negative urgency would predict levels of anger, aggression, and aggression control among those with IED. RESULTS The IED participants reported greater negative urgency than both comparison groups, and greater levels of positive urgency, reward sensitivity, and punishment sensitivity compared to HVs. Further, heightened negative urgency was the sole predictor an IED diagnosis. Within the IED group negative urgency uniquely predicted decreased aggression control and increased trait anger. LIMITATIONS Limitations included reliance on self-report measures to assess RS/PS, impulsivity, and aggression. CONCLUSIONS These findings suggest that negative urgency is a key factor associated with IED and is associated with dampened control of aggression within those with IED.

Forms of non-suicidal self-injury as a function of trait aggression

To date, the considerable body of research on predictors of non-suicidal self-injury (NSSI) has conceptualized NSSI as a unitary construct despite the fact that NSSI can exist in many forms (e.g., hitting, cutting, burning). The goal of the present study is to examine differential prediction of forms of NSSI. Specifically, we examined trait aggression as a predictor of more aggressive forms of NSSI (i.e., hitting). We hypothesized that higher trait aggression would differentiate those who engaged in hitting forms of NSSI from those who did not, whereas other factors (i.e., emotion regulation and trait anger) would serve as a non-specific predictor of NSSI. We also hypothesized that higher trait aggression would be related to lifetime frequency of hitting NSSI, but not other forms of NSSI, whereas emotion regulation and anger would act as predictors of other forms of NSSI. To test these hypotheses, a large sample of young adults completed measures of trait aggression, trait anger, emotion regulation, and NSSI behaviors. Results were generally in line with our hypotheses. Higher levels of trait aggression differentiated those who engaged in hitting NSSI from those who did not and was also associated with greater frequency of hitting NSSI. These results imply that different factors predict different forms of NSSI and that NSSI may be best examined as a multi-faceted construct.

The Relationship Between Nonsuicidal Self-Injury Age of Onset and Severity of Self-Harm

This study examined how age of nonsuicidal self-injury (NSSI) onset relates to NSSI severity and suicidality using decision tree analyses (nonparametric regression models that recursively partition predictor variables to create groupings). Those with an earlier age of NSSI onset reported greater NSSI frequency, NSSI methods, and NSSI-related hospital visits. No significant splits were found for suicide ideation or attempts, although those with an earlier onset were more likely to have a suicide plan. Overall, findings suggest that onset of NSSI before age 12 is associated with more severe NSSI and may be a crucial age for prevention efforts.

Measuring Acquired Capability for Suicide Within an Ideation-to-Action Framework.

Objective: Despite the large literature on risk factors for suicide-related outcomes, few studies have examined risk for acting on suicidal thoughts among suicide ideators. The current study aimed to fill this gap by examining the role of acquired capability, as well as its hypothesized facilitator, painful and provocative events (PPEs), as motivators for behavior among individuals along the suicide continuum. Method: Undergraduates reporting suicidal ideation, suicide plans, suicide attempts without intent to die, or suicide attempts with intent to die (N = 546) completed a measure of acquired capability for suicide, as well as assessments of exposure to PPEs. Results: Our findings demonstrated that acquired capability for suicide did not distinguish between individuals falling along the ideation-to-action spectrum. Among the several PPEs assessed, the frequency of nonsuicidal self-injury, and the presence of childhood emotional abuse, physical abuse, and physical neglect each significantly differentiated between groups, with individuals having a history of a suicide attempt with the intent to die reporting the highest levels. Conclusions: These findings implicate the PPEs that may be most important to assess in determining suicide risk, and, further, call into question the utility of acquired capability in differentiating between individuals along the suicide continuum.

Risk-Taking Behavior and Suicidality: The Unique Role of Adolescent Drug Use

Research has supported an association between suicidal thoughts/behaviors and risk taking, which may be particularly strong during adolescence when risk taking is known to increase. However, extant research has focused on individual risk-taking behaviors (e.g., alcohol use), limiting our ability to evaluate the unique association between different risk-taking behaviors and suicidal thoughts/behaviors. The current study aimed to fill this gap by examining the simultaneous influence of multiple risk-taking behaviors (i.e., risky sexual behavior, tobacco/alcohol use, illicit drug use, delinquent behavior, violent behavior) on adolescent suicidal thoughts/behaviors. Data from the National Longitudinal Study of Adolescent Health was utilized. The sample consisted of 4,834 adolescents who completed home interviews at two time points. At the first time point, participants’ mean age was 15.15, with 48% (n = 2,315) identifying as male. Participants provided information about suicidal thoughts/behaviors and multiple risk-taking behaviors at an initial interview and at a second interview, approximately 11 months later. When independently examined, nearly all assessed risk-taking behaviors were independently associated with suicidal ideation concurrently and prospectively, and with suicide attempts concurrently. When all risk-taking behaviors were examined simultaneously, illicit drug use was the only significant concurrent and significant prospective, albeit negative, predictor of suicidal thoughts and only concurrent predictor of suicidal behavior. The current findings suggest that illicit drug use may have a stronger association with suicidal thoughts and behaviors than other risk-taking behavior. These findings have implications for prevention and intervention programs for adolescents.

Suicidal behavior and aggression-related disorders

Studies of suicidal behavior among those with aggression-related disorders (i.e. intermittent explosive disorder, borderline personality disorder, antisocial personality disorder, and conduct disorder) were examined. The presence of an aggressive disorder generally increased the risk of suicide attempts and mortality, with this effect (when examined) usually existing independent of other psychopathology. However, this may not be the case for antisocial personality disorder. Furthermore, with the exception of intermittent explosive disorder, the extant research suggests severity of aggression was associated with suicide attempt risk in aggression-related disorders. Future research is needed to better understand what mechanisms may influence the suicide-aggression relationship.