Laboratory assessment of aggression: The Taylor Aggression Paradigm in adults with and without a disorder of impulsive aggression

INTRODUCTION

The modified Taylor Aggression Paradigm (TAP) has been used to study impulsive aggression in experimental designs and has been relatively successful in addressing critiques of aggression paradigms; however, little has been done to examine the potential of using the TAP as a direct measure of aggression. This study aimed to explore the psychometric properties of the TAP behavioral indexes as measures of aggression.

METHODS

A community sample of 962 adults were divided into three groups based on diagnostic assessments: Intermittent Explosive Disorder; Non-Aggressive Psychiatric Disorder; or healthy controls. Participants then completed the TAP and self-report measures to assess construct validity. A subset of 47 participants completed a second TAP within one year to assess reliability. TAP indexes were based on number of "extreme" shocks selected (high shock index), average shock levels selected (mean shock index), and shocks levels selected without provocation (unprovoked aggression).

RESULTS

Overall, TAP indexes were consistent and reliable. IED participants had the highest high shock and mean shock indexes of all groups (X2 = 49.93, p < 0.001). High shock index was related to trait aggression (β = 0.184, p < 0.001) after including covariates; mean shock index had a trending association with trait anger (β = 0.102, p = 0.059).

CONCLUSION

TAP behavioral indexes demonstrated promising psychometrics as a measure of aggression. High shock index appears to be more strongly associated with aggressive behavior; mean shock index may better measure general hostile responding. Future research might include comparisons specifically with impulse control disorders.

Gender Moderates the Association Between Exposure to Interpersonal Violence and Intermittent Explosive Disorder Diagnosis

Exposure to interpersonal violence (EIV) is a prevalent risk-factor for aggressive behavior; however, it is unclear whether the effect of EIV on clinically significant aggressive behavior is similar across gender. We examined whether gender moderates the association between experiencing and witnessing interpersonal violence and the diagnosis of intermittent explosive disorder (IED). We also examined potential pathways that might differentially account for the association between EIV and IED in men and women, including emotion regulation and social information processing (SIP). Adult men and women (N = 582), who completed a semistructured clinical interview for syndromal and personality disorders, were classified as healthy controls (HC; n = 118), psychiatric controls (PC; n = 146) or participants with an IED diagnosis (n = 318). Participants also completed the life history of experienced aggression (LHEA) and life history of witnessed aggression (Lhwa) structured interview and self-report measures of emotion regulation and SIP. Men reported more EIV over the lifetime. In multiple logistic regression analysis, experiencing and witnessing aggression within the family and experiencing aggression outside the family were associated with lifetime IED diagnosis. We found that the relationship between EIV and IED was stronger in women than in men. Affective dysregulation mediated certain forms of EIV, and this relation was observed in both men and women. SIP biases did not mediate the relation between EIV and IED. EIV across the lifespan is a robust risk factor for recurrent, clinically significant aggressive behavior (i.e., IED). However, the relationship between EIV and IED appears to be stronger in women. Further, this relation appears partially mediated by affective dysregulation.

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.

Anhedonia and the Relationship Between Other Depressive Symptoms and Aggressive Behavior

Depression has been linked to multiple forms of aggressive behavior in college students; however, it is unclear which aspects of depression explain this connection. Anhedonia, defined as the loss of interest and/or pleasure in previously enjoyed activities, may provide unique information about relationships between depression and aggression. Using cross-sectional data from two independent samples of college students (N = 747 and N = 736 for Study 1 and Study 2, respectively), we examined whether anhedonia helped explain the relationship between broader depressive symptoms and different forms of aggressive and antisocial behavior. Anhedonia accounted for variance in both self-directed aggression and antisocial behavior independent of gender, hostility, anger, other depressive symptoms, and cognitive distortions (Study 2). In addition, there were significant indirect effects of depressive symptoms on self-directed aggression (Studies 1 and 2) and antisocial behavior (Study 2) via anhedonia. Hypotheses involving other-directed aggression received mixed support, with anhedonia atemporally associated with other-directed aggression independent of broader depressive symptoms in Study 1, but not in Study 2. The current findings suggest that anhedonia is an important individual difference that helps explain the relationship between depression and aggressive and antisocial acts and that anhedonia may be differentially associated with various types of aggressive and antisocial behavior.

Evidence for the taxonic latent structure for DSM-5 intermittent explosive disorder in adults

BACKGROUND

Identification of individuals with clinically significant aggressive behavior is critical for the prevention and management of human aggressive behavior. A previous population-based taxometric study reported that the Diagnostic and Statistical Manual of Mental Disorders-4th Edition (DSM-IV) intermittent explosive disorder (IED) belongs to its own discrete class (taxon) rather than existing along a continuum.

METHODS

This study sought to extend previous population-based findings in a clinical research sample of adults with DSM-5 IED (n = 346), adults with non-aggressive DSM-5 disorders (n = 293), and adults without any DSM-5 disorder (n = 174), using standardized assessments of DSM-5 diagnoses, aggression, and other related measures not available in past studies.

RESULTS

Analyses revealed a taxonic latent structure that overlapped with the DSM-5 diagnosis of IED. Within the sample, taxon group members had higher scores on a variety of measures of psychopathology than did the complement members of the sample. Comorbidity of other diagnoses with IED did not affect these results.

CONCLUSION

These findings support the proposition that DSM-5 IED represents a distinct behavioral disorder rather than the severe end of an aggressive behavior continuum.

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.

Subtypes of aggression in intermittent explosive disorder

Research in aggression has distinguished two major subtypes of aggressive behavior: hostile and instrumental. Previous research has examined these subtypes in healthy individuals and forensic samples but not in intermittent explosive disorder (IED), a disorder characterized by recurrent and severe aggressive behavior. We examined aggression subtypes in individuals with IED, healthy subjects, and psychiatric control subjects. We also considered the relationship between aggression subtypes and measures of trait anger and impulsivity to evaluate whether the hostile/instrumental dichotomy adequately captures the heterogeneity of aggressive behavior in this sample. Finally, we consider the implications of these results for research on aggression, including neuroscience research on aggression.

Effect of alcohol dose on deliberate self-harm in men and women

OBJECTIVE

Nonexperimental survey and field research support the notion that alcohol use may be associated with deliberate self-harm (DSH) across the spectrum of lethality, from nonsuicidal self-injury (NSSI) through suicide. Nonexperimental studies, however, provide limited information about potential causal relationships between alcohol consumption and DSH. Two previous experiments showed that a relatively high-dose of alcohol increases the likelihood of engaging in DSH in men, with DSH defined by the self-administration of a "painful" shock (the self-aggression paradigm [SAP]; Berman & Walley, 2003; McCloskey & Berman, 2003). In this study, we examined whether (a) lower doses of alcohol also elicit DSH, (b) this effect occurs for women as well as men, and (c) individual differences in past nonsuicidal self-injury (NSSI) moderate alcohol's effects on DSH.

METHOD

Nonalcohol dependent men and women (N = 210) were assigned either to .00%, .05%, .075%, or .100% blood alcohol concentration (BAC) drink conditions and completed a self-rating scale of NSSI (the Deliberate Self-Harm Inventory [DSHI]; Gratz, 2001). As in previous SAP studies, DSH was operationalized by shock setting behavior during a competitive reaction time (RT) game.

RESULTS

Overall, a greater proportion of participants in the .075% and .100% (but not .050%) alcohol conditions self-selected a "painful" shock to administer compared to participants in the placebo condition. NSSI predicted self-administration of painful shocks, but did not moderate the alcohol effect.

CONCLUSIONS

Results provide experimental evidence to support the notion that interventions for self-harm should include processes to monitor and limit alcohol intake. (PsycINFO Database Record

Neural Correlates of Aggressive Behavior in Real Time: a Review of fMRI Studies of Laboratory Reactive Aggression

PURPOSE OF REVIEW

Aggressive behavior has adaptive value in many natural environments; however, it places substantial burden and costs on human society. For this reason, there has long been interest in understanding the neurobiological basis of aggression. This interest, and the flourishing of neuroimaging research in general, has spurred the development of a large and growing scientific literature on the topic. As a result, a neural circuit model of aggressive behavior has emerged that implicates interconnected brain regions that are involved in emotional reactivity, emotion regulation, and cognitive control.

RECENT FINDINGS

Recently, behavioral paradigms that simulate provocative interactions have been adapted to neuroimaging protocols, providing an opportunity to directly probe the involvement of neural circuits in an aggressive interaction. Here we review neuroimaging studies of simulated aggressive interactions in research volunteers. We focus on studies that use a well-validated laboratory paradigm for reactive physical aggression and examine the neural correlates of provocation, retaliation, and evaluating punishment of an opponent.

SUMMARY

Overall, the studies reviewed support the involvement of neural circuits that support emotional reactivity, emotion regulation, and cognitive control in aggressive behavior. Based on a synthesis of this literature, future research directions are discussed.

Intermittent Explosive Disorder and Substance Use Disorder: Analysis of the National Comorbidity Survey Replication Sample

OBJECTIVE

A relationship between aggression and substance use has been debated for many years. While substance use increases the risk of aggressive behavior, no studies have reported on the relationship between impulsive aggression and substance use/disorder, specifically.

METHODS

We analyzed data from the community-based National Comorbidity Survey Replication (N = 9,282 subjects) in order to examine the relationship between current DSM-5 intermittent explosive disorder (IED), a disorder of impulsive aggression, and current substance use disorders (SUDs), overall, and with regard to alcohol, tobacco, and cannabis use disorders and nondisordered use.

RESULTS

Occurrence of current SUD was elevated in current IED versus non-IED adult subjects, and onset of IED preceded that of SUD in 92.5% of comorbid IED + SUD cases. This relationship was not due to the presence, or absence, of current depressive or anxiety disorders. Examination of the severity of IED and of SUD revealed that the presence of IED increases SUD severity but that the presence of SUD does not increase IED severity.

CONCLUSIONS

Subjects with IED are at increased risk of developing SUD, compared with those without IED. This suggests that history of recurrent, problematic, impulsive aggression is a risk factor for the later development of SUD rather than the reverse. If so, effective treatment of impulsive aggression, before the onset of substance misuse, may prevent, or delay, the development of SUD in young people.

Social cognition in Intermittent Explosive Disorder and aggression

Social-emotional information processing (SEIP) was assessed in individuals with current DSM-5 Intermittent Explosive Disorder (IED: n = 100) and in healthy (n = 100) and psychiatric (n = 100) controls using a recently developed and validated self-rated questionnaire. SEIP vignettes depicted both direct aggressive and relationally aggressive scenarios of a socially ambiguous nature and were followed by questions assessing subjects' reactions and judgments about the vignettes. IED subjects differed from both healthy and psychiatric controls in all SEIP components. While hostile attribution was highly related to history of aggression, it was also directly correlated with negative emotional response. Further analysis revealed that this component, as well as response valuation and response efficiency, rather than hostile attribution, best explained history of aggressive behavior. A reformulated SEIP model, including self-reported history of childhood trauma, found that negative emotional response and response efficiency were the critical correlates for history of aggressive behavior. Psychosocial interventions of aggressive behavior in IED subjects may do well to include elements that work to reduce the emotional response to social threat and that work to restructure social cognition so that the tendency towards overt, or relationally, aggressive responding is reduced.

Differential fMRI BOLD responses in amygdala in intermittent explosive disorder as a function of past Alcohol Use Disorder

BACKGROUND

Individuals with intermittent explosive disorder (IED) were previously found to exhibit amygdala (AMYG) hyperactivation to anger faces during functional magnetic resonance imaging (fMRI). However, acute alcohol consumption, and/or life history of alcoholism, may blunt amygdala responses to negative emotional stimuli. Thus, we examined the influence of a past history of DSM-5 Alcohol Use Disorder (AUD) on the fMRI BOLD AMYG response to anger faces in IED.

METHOD

Forty-two IED participants, 18 with a past history of AUD (IED+AUD) and 24 without Past AUD (IED), and 32 healthy control (HC) participants, underwent fMRI scanning while viewing blocks of angry, fearful, and happy faces.

RESULTS

Compared to HC and IED+AUD participants, IED subjects exhibited greater AMYG responses to angry, but not to fear or happy, faces in the left AMYG. There were no group differences in responses to anger, fear, or happy, faces in the OFC.

CONCLUSION

These findings suggest the possibility of a longstanding effect of AUD on AMYG response in IED to anger-related stimuli and highlight the possibility that history of AUD should be considered as an important factor in the interpretation of fMRI studies involving the AMYG response to negative emotional stimuli.

Substance use disorders: Relationship with intermittent explosive disorder and with aggression, anger, and impulsivity

BACKGROUND

A relationship between substance use and aggression has been noted for decades. While substance use appears to be associated with an increased risk of aggressive behavior, no study has yet reported on the pattern of comorbidity and temporal relationship between impulsive aggression (i.e., intermittent explosive disorder) and substance use disorders (SUD), specifically.

METHODS

To specify these relationships, we examined DSM-5 diagnosis data from diagnostic interviews of 1355 adults who met one of five non-overlapping diagnostic subgroups: those with intermittent explosive disorder (IED; n = 339), those with SUD (n = 136), IED+SUD (n = 280), adults with psychiatric disorders but no SUD or IED (n = 320), and healthy

CONTROLS

HC, n = 282).

RESULTS

Occurrence of lifetime SUD was elevated in IED vs. all Non-IED subjects (Odds Ratio: 3.61 [95% CI: 2.82-4.63]) and onset of IED preceded SUD in 80% of comorbid IED+SUD cases. Examination of the severity of impulsive aggression and SUD revealed that IED increased SUD severity but the presence of SUD did not increase severity of IED core features, including aggression, anger, or impulsivity.

CONCLUSIONS

Subjects with IED are at increased risk of developing substance use disorder, compared to those without IED. This suggests that history of recurrent, problematic, impulsive aggression is a risk factor for the later development of SUD rather than the reverse. Thus, effective treatment of impulsive aggression, before the onset of substance misuse, may prevent or delay the development of SUD in young individuals.

Comorbid intermittent explosive disorder and posttraumatic stress disorder: Clinical correlates and relationship to suicidal behavior

OBJECTIVE

Posttraumatic stress disorder (PTSD) is associated with both aggressive and suicidal behavior. Recent research suggests that the diagnosis of intermittent explosive disorder (IED), an impulse-control disorder characterized by repeated impulsive aggressive behavior, may help to identify individuals at risk for attempting suicide. Given the relationship between anger and PTSD, there is likely to be an increased prevalence of IED among individuals with PTSD; however, little is known about the overlap in these two disorders, including how individuals with comorbid IED and PTSD may differ from those with either disorder alone. The purpose of this study is to examine the clinical correlates of comorbid IED and PTSD and the contribution of these two disorders (among others) to lifetime suicide attempt and characteristics of suicidal behavior.

METHOD

In a large sample of community research volunteers (N=1460), we compared individuals with PTSD, IED, and comorbid PTSD and IED on measures of current mood, trait aggression, and trait impulsivity. We also examined the contributions of PTSD, IED, and other syndromal and personality disorders to the prediction of lifetime aggression and lifetime suicide attempt, and their relationship to characteristics of suicide attempts, including level of intent, use of violent versus non-violent means, and the medical seriousness of the attempt.

RESULTS

Comorbid PTSD and IED was associated with significantly elevated levels of depression, anxiety, anger, aggression, and impulsivity, as well as with high rates of comorbidity with other psychiatric disorders. IED (β=.56, p<.001), but not PTSD, significantly and uniquely predicted lifetime aggressive behavior. Both IED and PTSD were associated with lifetime suicide attempt in multivariate analysis (ORs: 1.6 and 1.6, ps<.05). The results show that IED, when comorbid with PTSD, identifies a subgroup of individuals with particularly high levels of aggressive behavior and a high rate of suicide attempt (41.4% in this sample).

CONCLUSION

These findings add support to the notion that the diagnosis of IED may aid in identifying individuals at risk for aggressive and suicidal behavior.

Tryptophan, kynurenine, and kynurenine metabolites: Relationship to lifetime aggression and inflammatory markers in human subjects

Inflammatory proteins are thought to be causally involved in the generation of aggression, possibly due to direct effects of cytokines in the central nervous system and/or by generation of inflammatory metabolites along the tryptophan-kynurenine (TRP/KYN) pathway, including KYN and its active metabolites kynurenic acid (KA), quinolinic acid (QA), and picolinic acid (PA). We examined plasma levels of TRP, KYN, KA, QA, and PA in 172 medication-free, medically healthy, human subjects to determine if plasma levels of these substances are altered as a function of trait aggression, and if they correlate with current plasma levels of inflammatory markers. Plasma levels of C-reactive protein (CRP), interleukin-6 (IL-6), and soluble interleukin-1 receptor-II (sIL-1RII) protein were also available in these subjects. We found normal levels of TRP but reduced plasma levels of KYN (by 48%), QA (by 6%), and a QA/KA (by 5%) ratio in subjects with Intermittent Explosive Disorder (IED) compared to healthy controls and psychiatric controls. Moreover, the metabolites were not associated with any of the inflammatory markers studied. These data do not support the hypothesis that elevated levels of KYN metabolites would be present in plasma of subjects with IED, and associated with plasma inflammation. However, our data do point to a dysregulation of the KYN pathway metabolites in these subjects. Further work will be necessary to replicate these findings and to understand their role in inflammation and aggression in these subjects.

GH response to intravenous clonidine challenge correlates with history of childhood trauma in personality disorder

BACKGROUND

Childhood trauma is a risk factor for personality disorder. We have previously shown that childhood trauma is associated with increased central corticotrophin-releasing hormone concentration in adults with personality disorder. In the brain, the release of corticotrophin-releasing hormone can be stimulated by noradrenergic neuronal activity, raising the possibility that childhood trauma may affect the hypothalamic-pituitary adrenal (HPA) axis by altering brain noradrenergic function. In this study, we sought to test the hypothesis that childhood trauma is associated with blunted growth hormone response to the α-2 adrenergic autoreceptor agonist clonidine.

METHODS

All subjects provided written informed consent. Twenty personality disordered and twenty healthy controls (without personality disorder or Axis I psychopathology) underwent challenge with clonidine, while plasma Growth Hormone (GH) concentration was monitored by intravenous catheter. On a different study session, subjects completed the Childhood Trauma Questionnaire and underwent diagnostic interviews.

RESULTS

Contrary to our a priori hypothesis, childhood trauma was associated with enhanced GH response to clonidine. This positive relationship was present in the group of 40 subjects and in the subgroup 20 personality disordered subjects, but was not detected in the healthy control subjects when analyzed separately. The presence of personality disorder was unrelated to the magnitude of GH response.

DISCUSSION

Childhood trauma is positively correlated with GH response to clonidine challenge in adults with personality disorder. Enhanced rather that blunted GH response differentiates childhood trauma from previously identified negative predictors of GH response, such as anxiety or mood disorder.

Childhood trauma and parental style: Relationship with markers of inflammation, oxidative stress, and aggression in healthy and personality disordered subjects

Recent studies suggest that early life trauma is associated with elevations in circulating markers of inflammation in human subjects. History of aggression as a behavior, or aggression as a personality trait, is also associated with elevations of these inflammatory markers. Since early life trauma is associated with the development and maintenance of aggression in later life we examined the relationship of early life adversity, plasma inflammation markers (IL-6 and CRP) and oxidative stress markers (8-OH-DG and 8-ISO), and aggression in adult subjects with (n=79) and without (n=55) personality disorder. We used a series of mediated and moderated path models to test whether the effects of early adversity on later aggression may be mediated through markers of inflammation. Childhood abuse and parental control were associated with basal IL-6 and CRP concentrations. Path modeling suggested that childhood abuse was associated with aggression indirectly through CRP while parental control influenced aggression indirectly through IL-6 and CRP. Furthermore, these effects were independent of the effect of current depression. The results suggest that disruption of inflammatory processes represent one pathway by which early adversity influences aggression.

COMT Associations with Disordered Gambling and Drinking Measures

Disordered gambling and alcohol dependence are influenced by unique and shared genetic factors. Although the evidence is mixed, some research has linked catechol-O-methyltransferase (COMT) rs4680 (or COMT Val158Met) to the development of gambling or drinking problems; however, no molecular genetic study has jointly examined gambling and drinking problems. Furthermore, the majority of past studies examined gambling or drinking problems using a case-control design. The purpose of the current study was to examine associations of COMT rs4680 with dimensionally and categorically measured gambling and drinking problems in a nonclinical sample (139 Caucasian adults). The current study found that COMT rs4680 was related to both dimensionally and categorically measured gambling and drinking problems. It appears that the COMT Met/Met genotype may be a genetic risk factor that contributes to the development of both gambling and drinking problems.

History of childhood maltreatment in intermittent explosive disorder and suicidal behavior

Intermittent Explosive Disorder (IED) is a relatively common disorder of impulsive aggression that typically emerges by adulthood. Maltreatment in childhood (CM) may contribute to the development of IED, but little is known about the association between CM and IED, including about how subtypes of CM may specifically relate to IED. This study aimed to test the association between CM and IED diagnosis. A second aim was to examine history of CM in suicide attempters, and to explore whether impulsivity and aggression account for the relationship between CM and suicide attempt (SA). Adults with Intermittent Explosive Disorder (IED; n = 264), with non-IED psychiatric (Axis I or II) disorders (psychiatric controls; PC; n = 199), and with no psychiatric disorder (healthy control subjects; HC; n = 185) were assessed for history of childhood maltreatment, aggression, impulsivity, and history of SA. IED subjects reported significantly greater CM compared to PC and HC subjects, and suicide attempters (n = 62) reported greater CM compared to non-attempters (n = 586). Physical abuse in childhood was independently associated with IED, while sexual abuse and emotional abuse were independently associated with SA. Impulsivity and aggression were potential mediators of the relationship between physical abuse and IED and emotional abuse and SA, but sexual abuse was associated with SA independently of aggression and impulsivity. The results suggest pathways by which environmental factors may influence impulsivity and aggression and, in turn, clinically significant self- and other-directed aggression.

Serotonin (5-HT) augmentation reduces provoked aggression associated with primary psychopathy traits

Psychopathy has long been associated with aggressive behavior; however, the neurochemical underpinnings of this relationship are poorly understood. Serotonin (5-HT) neurotransmitter system abnormalities have been associated with provoked aggression in general. In addition, 5-HT dysregulation has been linked to empathy, a trait that is lacking in individuals who score high on primary psychopathy. The purpose of this study was to determine if 5-HT modulates the relationship between psychopathic traits and aggression. Participants (N = 47) completed a self-report measure of psychopathy and were then administered either 40 mg paroxetine (acutely augmenting 5-HT) or placebo. Aggression was assessed during a competitive reaction-time game in which electric shocks were exchanged with an increasingly provocative fictitious opponent. Results indicated that primary psychopathy (but not secondary psychopathy) was related to aggressive responding to provocation. Moreover, 5-HT augmentation attenuated this effect, supporting the notion that aggressive responding associated with primary psychopathic traits may be due in part to 5-HT dysregulation.

Social cognitive deficits in schizophrenia and their relationship to clinical and functional status

While research on social cognitive impairments in schizophrenia is quickly growing, relatively little is still known about the severity and correlates of these impairments. The few studies that have examined this issue suggest that social cognitive impairments may be positively related to psychiatric symptoms and negatively related to functioning. In the current analyses of 119 stable outpatients with schizophrenia spectrum diagnoses, we sought to further characterize the nature of social cognitive impairments in schizophrenia. Specifically, we examined (1) social cognitive impairments on four different social cognitive tasks including measures of emotional processing and Theory of Mind and (2) the demographic, symptom and functional correlates of these impairments. For three of the four social cognitive tasks examined, the majority of participants performed 1 or more S.D. worse than healthy controls, with variability in the degree of impairment across tasks. Contrary to expectation, correlations between social cognitive performance on each of the four tasks and clinical and functional features were few and weak, and for the most part did not replicate the previously reported relationship of social cognition to severity of symptoms or current functional status.

Is it possible to have impaired neurocognition but good social cognition in schizophrenia?

Social cognitive impairment in schizophrenia is common and associated with poor functional outcome. While correlations in the moderate range suggest that social cognition and neurocognition are separate but overlapping domains, less is known about whether intact neurocognition represents a "necessary but not sufficient" condition for intact social cognition, as has been suggested. In the present study we examined the following in a sample of 119 psychiatrically stable outpatients with schizophrenia: 1) correlations between multiple social cognitive measures and neurocognition, 2) the predictive value of neurocognitive domains in explaining social cognitive performance, and 3) the co-occurrence of social cognitive and neurocognitive impairment within participants. While ¼ of participants showed intact overall neurocognition and impaired overall social cognition, only one participant had normal-range social cognition and impaired neurocognition. Results support the notion that normal range neurocognition is a necessary though not necessarily sufficient building block for good social cognitive performance.

Effects of alcohol on tests of executive functioning in men and women: a dose response examination

Alcohol has been shown to affect performance on tasks associated with executive functioning. However, studies in this area have generally been limited to a single dose or gender or have used small sample sizes. The purpose of this study was to provide a more nuanced and systematic examination of alcohol's effects on commonly used tests of executive functioning at multiple dosages in both men and women. Research volunteers (91 women and 94 men) were randomly assigned to one of four drink conditions (alcohol doses associated with target blood alcohol concentrations of .000%, .050%, .075%, and .100%). Participants then completed three tasks comprising two domains of executive functioning: two set shifting tasks, the Trail Making Test and a computerized version of the Wisconsin Card Sorting Task, and a response inhibition task, the GoStop Impulsivity Paradigm. Impaired performance on set shifting tasks was found at the .100% and .075% dosages, but alcohol intoxication did not impair performance on the GoStop. No gender effects emerged. Thus, alcohol negatively affects set shifting at moderately high levels of intoxication in both men and women, likely attributable to alcohol's interference with prefrontal cortex function. Although it is well established that alcohol negatively affects response inhibition as measured by auditory stop-signal tasks, alcohol does not appear to exert a negative effect on response inhibition as measured by the GoStop, a visual stop-signal task.

Serotonin augmentation reduces response to attack in aggressive individuals

We tested the theory that central serotonin (5-hydroxytryptamine, or 5-HT) activity regulates aggression by modulating response to provocation. Eighty men and women (40 with and 40 without a history of aggression) were randomly assigned to receive either 40 mg of paroxetine (to acutely augment serotonergic activity) or a placebo, administered using double-blind procedures. Aggression was assessed during a competitive reaction time game with a fictitious opponent. Shocks were selected by the participant and opponent before each trial, with the loser on each trial receiving the shock set by the other player. Provocation was manipulated by having the opponent select increasingly intense shocks for the participant and eventually an ostensibly severe shock toward the end of the trials. Aggression was measured by the number of severe shocks set by the participant for the opponent. As predicted, aggressive responding after provocation was attenuated by augmentation of serotonin in individuals with a pronounced history of aggression.

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.