Imitation of Self-Aggressive Behavior: An Experimental Test of the Contagion Hypothesis1

Analgesic Effect of Alcohol Mediates the Association between Alcohol Intoxication and Deliberate Self-Harm

We examined whether the analgesic effect of alcohol mediates the association between alcohol and deliberate self-harm (DSH) using data from a larger study on alcohol effects. Men (n = 106) and women (n = 104) low-risk alcohol drinkers (ages M = 26.00, SD = 6.98) recruited from the community who had no suicide attempt or episode of deliberate self-harm within the past year were randomly assigned to either a placebo drink condition or a drink calibrated to reach approximately .050%, .075%, or .100% blood alcohol concentration. Notable within-condition BAC variability, as well as overlap between conditions, suggested that BAC would be a more accurate indicator of intoxication compared to condition assignment. Pain tolerance was assessed by increasingly intense 1-s shocks delivered via fingertip electrodes. Self-reported pain associated with the pain tolerance index was also examined. A laboratory task of DSH, the Self-Aggression Paradigm, was then completed, with DSH operationalized as the number of self-administered shocks the participant was led to believe were twice the intensity of his or her pain tolerance and could cause "minor tissue damage that would quickly heal." A negative binomial parallel mediational model for count data revealed that pain tolerance, but not self-report pain, mediated the effect of alcohol on DSH. As such, the current study provides preliminary experimental evidence that the analgesic effect of alcohol is partially responsible for link between alcohol intoxication and deliberate self-harm.

An experimental examination of interpersonal problem-solving in nonsuicidal self-injury: A pilot study

Nonsuicidal self-injury (NSSI) typically occurs in the presence of negative emotions. Prior research has emphasized interpersonal stress as a specific context that may elevate negative emotions in this population and even increase the likelihood of NSSI behavior. However, the factors that contribute to the relationship between interpersonal stress and NSSI have received relatively limited attention. The current pilot study aimed to experimentally examine interpersonal problem-solving as a potential moderator of the interpersonal stress - NSSI risk relationship among those with a NSSI history. Eighty-six participants (52.3% with NSSI history) were randomly assigned to one of three mood induction conditions (interpersonal negative, general negative, interpersonal neutral), after which they completed an interpersonal problem-solving task and a laboratory analogue of self-injurious behavior. Results indicated that NSSI history was associated with poorer interpersonal effectiveness. Further, individuals with a history of NSSI who experienced an interpersonally-focused negative mood and produced less effective interpersonal solutions were more self-harming on a laboratory analogue of self-injurious behavior. While the present findings are preliminary in nature, they offer guidance for research moving forward and, if replicated, suggest interpersonal problem-solving as a potential treatment target among individuals engaging in NSSI.

Potential Mood Variation Following a Behavioral Analogue of Self-Injurious Behavior

Despite increased use of behavioral analogues to identify casual mechanisms of self-injurious behavior (e.g., suicide attempts; non-suicidal self-injury), little is known about the impact on participants. The current study examined the impact of a specific behavior analogue, Self-Aggressive Paradigm (SAP), on participant affect. Community participants (n = 507) reported several affective ratings before and after completing SAP task procedures. Following the SAP, participants reported reductions in nervousness and fear and increases in calmness and anger (d = .21). Participants with a current anxiety disorder reported greater increases in happiness; those with a suicide attempt history reported greater increases in sadness. Findings demonstrate the SAP has no adverse mood effects, supporting its use in experimental research.

Does State Dissociation Mediate the Relation Between Alcohol Intoxication and Deliberate Self-Harm?

Research supports the notion that alcohol intoxication is a risk factor for deliberate self-harm (DSH). However, the underlying mechanisms for this relationship are poorly understood. We aimed to determine whether alcohol-induced dissociation mediated alcohol's effects on DSH. We used data from a dose-response study of alcohol intoxication and DSH to test the proposed model. Participants were assigned to reach target blood alcohol concentrations (BAC) ranging from 0.00% through 0.10% and then completed a behavioral measure of DSH. Dissociation was assessed using the Alcohol Dissociative Experiences Scale. BAC predicted both dissociation and DSH, but dissociation did not predict DSH. Although research on clinical populations suggests dissociation is related to DSH, our findings suggest dissociation does not mediate the effects of alcohol on self-harm.

Assessing Non-Suicidal Self-Injury in the Laboratory

The majority of non-suicidal self-injury (NSSI) research has used self- or clinician-rated measures of behavior which (a) are subject to reporting biases, or (b) have limited use in experimental designs that could illuminate causal relationships. Laboratory-based behavioral tasks have therefore been developed to assess NSSI-related behaviors more directly. We reviewed the behavioral methods that have been developed to assess NSSI tendencies or behaviors over the past 30 years. Several categories of laboratory analogues were identified: NSSI-related stimuli (e.g., NSSI pictures, implicit association tasks, guided imagery), experimenter administered pain stimuli (e.g., cold, heat, pressure, shock, and blade), and self-selected pain stimuli (e.g., cold and shock). These behavioral methods assess various aspects of NSSI and all have distinct advantages and shortcomings. Overall, these approaches have made significant contributions to the field complementing self- and clinician-ratings.

A Social Exclusion Manipulation Interacts with Acquired Capability for Suicide to Predict Self-Aggressive Behaviors

The interpersonal theory of suicide posits that individuals who simultaneously experience high levels of thwarted belongingness, perceived burdensomeness, and acquired capability for suicide are at high risk for a lethal or near-lethal suicide attempt. Although supported by self-report studies, no study has examined facets of the theory experimentally. The present study aimed to examine the belongingness and capability components of the theory by testing whether experimentally manipulated social exclusion interacts with self-reported acquired capability to predict higher self-administered shock levels on a self-aggression paradigm. A sample of 253 students completed self-report measures and were then randomly assigned to a social exclusion manipulation condition (future alone, future belonging, no feedback). Participants then participated in the self-aggression paradigm. The positive association between acquired capability and self-aggression was strongest among participants in the future alone social exclusion condition. In those assigned to the future belonging or no feedback conditions, the association between acquired capability and self-aggression was non-significant. These findings provide modest experimental support for the interpersonal theory of suicide and highlight a potential mechanism through which social exclusion may impact suicide risk. Limitations and future research directions are discussed.

The Associations Between Children's and Adolescents' Suicidal and Self-Harming Behaviors, and Related Behaviors Within Their Social Networks: A Systematic Review

Social influences-including the suicidal and self-harming behaviors of others-have been highlighted as a risk factor for suicidal and self-harming behavior in young people, but synthesis of the evidence is lacking. A systematic review of 86 relevant papers was conducted. Considerable published evidence was obtained for positive associations between young people's suicidal and self-harming behavior and that of people they know, with those reporting knowing people who had engaged in suicidal or self-harming behaviors more likely to report engaging in similar behaviors themselves. Findings are discussed in relation to a number of methodological and measurement issues-including the role of normative perceptions-and implications for the prevention of suicidal and self-harming behavior are considered.

The relationship between intentional self-injurious behavior and the loudness dependence of auditory evoked potential in research volunteers

OBJECTIVE

Serotonergic (5-HT) functioning has been shown to be inversely associated with intentional self-injurious behaviors. The purpose of this study was to examine the association between three related self-report measures of intentional self-injurious behaviors (suicidal thoughts/behavior, history of nonsuicidal self-injury, history of severe self-harm when angry) and a putative electrophysiological index of 5-HT activity, the loudness dependence of auditory evoked potential (LDAEP).

METHOD

Auditory evoked potentials were recorded from 41 men (mean age = 20.69, standard deviation [SD] = 2.98) during the administration of various tone loudness stimuli, followed by completion of the self-report measures.

RESULTS

The component slope was associated with all measures of self-injurious behavior in the expected direction.

CONCLUSION

The LDAEP has the potential to be used as a noninvasive index of intentional self-harm disposition. Additional studies are needed using other populations, including women and treatment-seeking individuals, to determine if the LDAEP more broadly discriminates risk of self-injuring.

The best friend and friendship group influence on adolescent nonsuicidal self-injury

This study examined associations of peer socialization and selection, over time, with nonsuicidal self-injury (NSSI) among 5,787 (54.2 % females) Chinese community adolescents. Both effects were tested using two aspects of adolescents' friendship networks: the best friend and the friendship group. Participants completed questionnaires assessing NSSI, depressive symptoms and maladaptive impulsive behaviors at two waves of time over a 6-month period. Results showed that even after controlling for the effects of depressive symptoms and maladaptive impulsive behaviors, the best friends' engagement in NSSI still significantly predicted adolescents' own engagement in NSSI. Adolescents' friendship groups' NSSI status also significantly predicted their own NSSI status and frequency. Additionally, adolescents with NSSI tended to join peer groups with other members also engaging in NSSI.

Pain and suicidality: insights from reward and addiction neuroscience

Suicidality is exceedingly prevalent in pain patients. Although the pathophysiology of this link remains unclear, it may be potentially related to the partial congruence of physical and emotional pain systems. The latter system's role in suicide is also conspicuous during setbacks and losses sustained in the context of social attachments. Here we propose a model based on the neural pathways mediating reward and anti-reward (i.e., allostatic adjustment to recurrent activation of the reward circuitry); both are relevant etiologic factors in pain, suicide and social attachments. A comprehensive literature search on neurobiology of pain and suicidality was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) physical and emotional pain, (2) emotional pain and social attachments, (3) pain- and suicide-related alterations of the reward and anti-reward circuits as compared to addiction, which is the premier probe for dysfunction of these circuits and (4) mechanistically informed treatments of co-occurring pain and suicidality. Pain-, stress- and analgesic drugs-induced opponent and proponent states of the mesolimbic dopaminergic pathways may render reward and anti-reward systems vulnerable to sensitization, cross-sensitization and aberrant learning of contents and contexts associated with suicidal acts and behaviors. These findings suggest that pain patients exhibit alterations in the brain circuits mediating reward (depressed function) and anti-reward (sensitized function) that may affect their proclivity for suicide and support pain and suicidality classification among other "reward deficiency syndromes" and a new proposal for "enhanced anti-reward syndromes". We suggest that interventions aimed at restoring the balance between the reward and anti-reward networks in patients with chronic pain may help decreasing their suicide risk.

Interpersonal features and functions of nonsuicidal self-injury

Etiological models of nonsuicidal self-injury (NSSI) suggest interpersonal features may be important to understand this behavior, but social functions and correlates have not been extensively studied. This study addresses existing limitations by examining interpersonal correlates and functions of NSSI within a stratified random sample of 1,243 predominantly Caucasian college students (mean age = 21.52, SD = 4.15 years). Participants completed an anonymous online survey assessing NSSI features, perceived social support, and disclosure experiences. Approximately 15% of the students endorsed NSSI. Interpersonal reasons were endorsed proportionally more often for initiating rather than repeating the behavior. Individuals with repetitive NSSI reported significantly lower perceived social support from family members and fewer individuals to seek advice from than single-act and control participants. Fifty-nine percent had disclosed their NSSI, but rarely to mental health professionals. Conversations with others about NSSI were rated as being mostly unhelpful. These results emphasize the importance of interpersonal features and functions of NSSI, suggesting treatments should focus on strengthening interpersonal bonds alongside emotion regulation. Improving responses to disclosures of NSSI is needed to promote communication about this behavior and perceived helpfulness of such conversations.

Nonsuicidal self-injury: relationship to behavioral and self-rating measures of impulsivity and self-aggression

Previous research using self-report measures has shown an association between nonsuicidal self-injurious behavior (NSSI) and impulsive tendencies. However, self-injurers have not been shown to be different from comparison groups on laboratory tasks putatively assessing impulsive behavior. One explanation for these contradictory findings is that self-report and laboratory measures of impulsive behavior tap into distinct but related constructs. Moreover, performance on laboratory measures of impulsive behavior can be influenced by myriad contextual and affective factors not present during past self-reported NSSI events. Accordingly, a relationship between behavioral tasks of impulsivity and self-injurious behavior could emerge if both are assessed relatively close in time under controlled laboratory conditions. To test this possibility, both self-ratings and laboratory task measures of self-injurious and impulsive behavior were employed in the current study. This multi-modal assessment approach revealed that self-rated impulsivity was associated with both self-report and behavioral measures of self-injurious behavior. Moreover, behavioral measures of impulsivity were associated with self-injurious behavior, but not NSSI history. These results provide support for the notion that a multi-modal approach to assessing self-injurious behavior is important for better understanding the correlates of nonsuicidal self-injury.

Peer influence and nonsuicidal self injury: longitudinal results in community and clinically-referred adolescent samples

Research suggests that adolescents' engagement in nonsuicidal self-injurious (NSSI) behaviors may be increasing over time, yet little is known regarding distal longitudinal factors that may promote engagement in these behaviors. Data from two longitudinal studies are presented to examine whether NSSI may be associated with peer influence processes. Study 1 included 377 adolescents from a community-based sample; Study 2 included 140 clinically-referred adolescents recruited from a psychiatric inpatient facility. In Study 1, adolescents' NSSI was examined at baseline and one year later. Adolescents' nominated best friend reported their own levels of NSSI. In Study 2, adolescents' NSSI was examined at baseline as well as 9 and 18-months post-baseline. Adolescents' perceptions of their friends' engagement in self-injurious behavior (including suicidality) and depressed mood also were examined at all three time points. Baseline depressive symptoms were measured in both studies; gender and age were examined as moderators of peer influence effects. Results from both studies supported longitudinal peer socialization effects of friends' self-injurious behavior on adolescents' own NSSI for girls, but not for boys, even after controlling for depressive symptoms as a predictor. Study 1 suggested socialization effects mostly for younger youth. Results from Study 2 also suggested longitudinal socialization effects, as well as peer selection effects; adolescents' NSSI was associated with increasing perceptions of their friends' engagement in depressive/self-injurious thoughts and behavior. Findings contribute to the nascent literature on longitudinal predictors of NSSI and to work on peer influence.

Acute tryptophan depletion and self-injurious behavior in aggressive patients and healthy volunteers

RATIONALE

An association between serotonin (5-HT) activity and self-injurious (i.e., self-aggressive) behavior across the spectrum of lethality (from self-mutilation through completed suicide) is a well-replicated finding. Studies to date, however, have relied on nonexperimental designs to examine this relationship, limiting the causal inferences that can be drawn about the role of 5-HT in self-aggressive behavior.

OBJECTIVE

Examine the effect of experimentally altered 5-HT activity (via dietary tryptophan depletion) on self-aggressive behavior among adults with and without intermittent explosive disorder (IED). Individuals with a marked history of aggression, such as those with IED, are characterized by compromised 5-HT and heightened risk for self-aggression, making this a population of interest for examining the proposed relations.

MATERIALS AND METHODS

IED patients (n = 16) and healthy controls (n = 16) received a tryptophan depletion and a placebo drink on separate days at least 1 week apart. Self-aggressive behavior was assessed on both study days using a well-validated laboratory-based behavioral assessment with self-aggression defined as the intensity of shock self-administered.

RESULTS

Tryptophan depletion facilitated selection of more intense shocks, on average, in both groups. Patients with IED were also more self-aggressive overall than healthy volunteers. No IED by drink condition interactions were found.

CONCLUSION

Experimentally lowered 5-HT bioavailability enhances overall self-injurious behavior irrespective of aggression history.

Self-focused attention reduces self-injurious behavior in alcohol-intoxicated men

Both chronic alcohol use and acute intoxication are risk factors for self-aggression (i.e., intentional self-injury) across the spectrum of lethality. Studies designed to identify a cause-and-effect relation between alcohol intoxication and self-aggression, or the factors that facilitate or mitigate this effect, are rare due to the inherent difficulty of studying self-injurious behavior experimentally. In this study, we experimentally demonstrate that alcohol intoxication leads to heightened self-injurious behavior, and that enhanced self-focused attention (self-awareness) attenuates this effect. Specifically, 40 men consumed either alcohol (mean Blood Alcohol Concentration [BAC] = .10) or a veridical control drink, and then completed a laboratory task designed to assess self-injurious behavior. Self-focused attention was experimentally enhanced in half the participants in each drink condition. Results support the notion that prevention and intervention programs designed to reduce intentional self-injurious behaviors should include components that address alcohol misuse and self-awareness.

A prospective study of child maltreatment and self-injurious behavior in a community sample

In conjunction with prospective ratings of child maltreatment (i.e., sexual abuse, physical abuse, and physical neglect) and measures of dissociation and somatization, this study examined prospective pathways between child maltreatment and nonsuicidal, direct self-injurious behavior (SIB; e.g., cutting, burning, self-hitting). Ongoing participants in the Minnesota Longitudinal Study of Parents and Children (N = 164; 83 males, 81 females) completed a semistructured interview about SIB when they were 26 years old. SIB emerged as a heterogeneous and prominent phenomenon in this low-income, mixed-gender, community sample. Child sexual abuse predicted recurrent injuring (i.e., three or more events; n = 13), whereas child physical abuse appeared more salient for intermittent injuring (i.e., one to two events; n = 13). Moreover, these relations appeared largely independent of risk factors that have been associated with child maltreatment and/or SIB, including child cognitive ability, socioeconomic status, maternal life stress, familial disruption, and childhood exposure to partner violence. Dissociation and somatization were related to SIB and, to a lesser degree, child maltreatment. However, only dissociation emerged as a significant mediator of the observed relation between child sexual abuse and recurrent SIB. The findings are discussed within a developmental psychopathology framework in which SIB is viewed as a compensatory regulatory strategy in posttraumatic adaptation.

Remitted depression moderates self-injurious behavior in personality-disordered research volunteers

The moderating effects of depression on self-injurious behavior among personality-disordered individuals (N=40) were examined. Self-injurious behavior (SIB) was assessed using a well-validated laboratory measure. Remitted depression was associated with greater sensitivity to self-aggressive cues, indicating that remitted depression may be a risk factor for SIB.

Anxiety sensitivity and retaliatory aggressive behavior in research volunteers

An important focus of recent aggression research has been to identify personality variables that influence the expression of aggression. One such variable may be anxiety sensitivity (AS). Individuals high in AS fear unpleasant anxiety-related physiological sensations and perhaps physiological arousal in general. Accordingly, people high in AS are motivated to avoid situations that produce these sensations. With respect to aggressive encounters, an intense attack by an opponent involves significant physiological arousal. High anxiety-sensitive individuals may therefore attempt to decrease the intensity of the interaction by responding in a non-aggressive or conciliatory manner. To test this possibility, 112 community volunteers completed a measure of AS and a well-validated laboratory task designed to assess aggressive behavior. As predicted, an inverse relation between AS and extreme aggressive responding was found. Specifically, as AS increases, retaliatory aggression is less likely after intense attack by an opponent.

The effects of diazepam on human self-aggressive behavior

RATIONALE

Diazepam, a benzodiazepine with a relatively rapid onset of clinical effects, has been associated with suicide and other self-aggressive acts. The evidence for this association, however, comes exclusively from retrospective non-experimental studies. Although suggestive, the results of these studies do not support a cause-and-effect relationship between benzodiazepine consumption and self-aggressive behavior.

OBJECTIVE

To experimentally examine the effect of diazepam on human self-aggressive behavior under controlled laboratory conditions.

METHOD

Forty-six healthy men and women were randomly assigned to receive placebo, or 5 mg or 10 mg diazepam in a double-blind, between-groups design. Participants were then provided the opportunity to self-administer electric shocks during a competitive reaction-time task (the self-aggression paradigm, SAP). Self-aggression was defined by the intensity of shock chosen.

RESULTS

Diazepam (10 mg) was associated with higher average shock self-administered than placebo. Subjects receiving 10 mg diazepam were also more likely to attempt to self-administer a shock that they were led to believe was "severe" and painful. Sedation effects were found, but diazepam consumption did not impair memory, attention, concentration, pain threshold, or reaction-time performance.

CONCLUSIONS

Clinically relevant diazepam doses may be associated with self-aggressive behaviors at levels that do not significantly impair basic cognitive processes or psychomotor performance.