Reduction of appeasement-related affect as a concomitant of diazepam-induced aggression: evidence for a link between aggression and the expression of self-conscious emotions

Impulsivity and Perpetration of Intimate Partner Aggression: The Moderating Effects of Negative Affective State and Alcohol

Background: The goal of this study was to test the interactive effects of negative urgency, state negative affect, and alcohol intoxication on intimate partner aggression (IPA) perpetration. Methods: Heavy drinkers who recently perpetrated IPA completed self-report measures of impulsivity, were administered an alcohol or control beverage, and completed a laboratory aggression task. State negative affect was assessed unobtrusively via the Facial Action Coding System. Results: Consistent with our prediction, negative urgency was significantly and positively related to IPA when state negative affect was also high, but this relation was not significant when state negative affect was low. Conclusions: These results have implications for understanding the role of negative affect and impulsivity in IPA perpetration and for understanding trait models of impulsivity in general.

Cognitive and Affective Mediators of Alcohol-Facilitated Intimate Partner Aggression

This multisite study examined whether aggressive cognitions and facial displays of negative affect and anger experienced during provocation mediated the association between alcohol intoxication and intimate partner aggression (IPA). Participants were 249 heavy drinkers (148 men, 101 women) with a recent history of IPA perpetration. Participants were randomly assigned to an Alcohol or No-Alcohol Control beverage condition and completed a shock-based aggression task involving apparent provocation by their intimate partner. During provocation, a hidden camera recorded participants' facial expressions and verbal articulations, which were later coded using the Facial Action Coding System and the Articulated Thoughts in Simulated Situations paradigm. Results indicated that the positive association between alcohol intoxication and partner-directed physical aggression was mediated by participants' aggressive cognitions, but not by negative affect or anger facial expressions. These findings implicate aggressogenic cognitions as a mediating mechanism underlying the association between the acute effects of alcohol and IPA perpetration.

Diazepam actions in the VTA enhance social dominance and mitochondrial function in the nucleus accumbens by activation of dopamine D1 receptors

Benzodiazepines can ameliorate social disturbances and increase social competition, particularly in high-anxious individuals. However, the neural circuits and mechanisms underlying benzodiazepines' effects in social competition are not understood. Converging evidence points to the mesolimbic system as a potential site of action for at least some benzodiazepine-mediated effects. Furthermore, mitochondrial function in the nucleus accumbens (NAc) has been causally implicated in the link between anxiety and social competitiveness. Here, we show that diazepam facilitates social dominance, ameliorating both the competitive disadvantage and low NAc mitochondrial function displayed by high-anxious rats, and identify the ventral tegmental area (VTA) as a key site of action for direct diazepam effects. We also show that intra-VTA diazepam infusion increases accumbal dopamine and DOPAC, as well as activity of dopamine D1- but not D2-containing cells. In addition, intra-NAc infusion of a D1-, but not D2, receptor agonist facilitates social dominance and mitochondrial respiration. Conversely, intra-VTA diazepam actions on social dominance and NAc mitochondrial respiration are blocked by pharmacological NAc micro-infusion of a mitochondrial complex I inhibitor or an antagonist of D1 receptors. Our data support the view that diazepam disinhibits VTA dopaminergic neurons, leading to the release of dopamine into the NAc where activation of D1-signaling transiently facilitates mitochondrial function, that is, increased respiration and enhanced ATP levels, which ultimately enhances social competitive behavior. Therefore, our findings critically involve the mesolimbic system in the facilitating effects of diazepam on social competition and highlight mitochondrial function as a potential therapeutic target for anxiety-related social dysfunctions.

Motivational drive and alprazolam misuse: A recipe for aggression?

Benzodiazepine-related aggression has received insufficient research attention, in particular little is known about the motivational factors which may contribute to the development of this paradoxical response. The revised Reinforcement Sensitivity Theory provides a theoretical framework from which to understand the relevant underlying motivational processes. The current study aimed to identify the role of approach and avoidance motivational tendencies in the occurrence of benzodiazepine-related aggression. Data regarding benzodiazepine and other substance use, approach and avoidance motivation, and general and physical aggressive behaviour were collected via self-report questionnaires. Participants were a convenience sample (n=204) who reported using benzodiazepines in the previous year. Participants were primarily male (62.7%), aged 18-51 years old. Hierarchical multiple regressions indicated that general and physical aggression were predicted by alprazolam use and Drive, a facet of approach motivation. Overall, lower diazepam use significantly predicted higher levels of general aggression. However, when diazepam-preferring participants were examined in isolation of the larger sample (23.5% of sample), problematic (dependent) diazepam use was associated with greater aggression scores, as was dependence risk for alprazolam-preferring participants (39.7% of sample). The findings highlight the importance of motivational factors and benzodiazepine use patterns in understanding benzodiazepine-related aggression, with implications for violent offender rehabilitation.

α2-containing GABA(A) receptors: a requirement for midazolam-escalated aggression and social approach in mice

RATIONALE

Benzodiazepines (BZDs) are prescribed to reduce anxiety, agitation, and muscle spasms and for their sedative-hypnotic and anticonvulsant effects. Under specific conditions, BZDs escalate aggression in some individuals. Specific effects of BZDs have been linked to the α-subunit subtype composition of GABAA receptors.

OBJECTIVES

Point-mutated mice rendered selectively insensitive to BZDs at α1-, α2-, or α3-containing GABAA receptors were used to determine which α-subunit subtypes are necessary for BZDs to escalate aggression and social approach and to reduce fear-motivated behavior.

METHODS

During resident-intruder confrontations, male wild-type (WT) and point-mutated α1(H101R), α2(H101R), and α3(H126R) mice were treated with midazolam (0-1.7 mg/kg, i.p.) and evaluated for aggression in an unfamiliar environment. Separate midazolam-treated WT and point-mutated mice were assessed for social approach toward a female or investigated in a 6-day fear-potentiated startle procedure.

RESULTS

Moderate doses of midazolam (0.3-0.56 mg/kg, i.p.) escalated aggression in WT and α3(H126R) mutants and increased social approach in WT and α1(H101R) mice. The highest dose of midazolam (1.0 mg/kg) reduced fear-potentiated startle responding. All mice were sensitive to the sedative effect of midazolam (1.7 mg/kg) except α1(H101R) mutants.

CONCLUSIONS

Midazolam requires BZD-sensitive α1- and α2-containing GABAA receptors in order to escalate aggression and α2- and α3-containing receptors to reduce social anxiety-like behavior. GABAA receptors containing the α1-subunit are crucial for BZD-induced sedation, while α2-containing GABAA receptors may be a shared site of action for the pro-aggressive and anxiolytic effects of BZDs.

Mechanisms of Alcohol-Facilitated Intimate Partner Violence

Intimate partner violence (IPV) is a critical public health problem that requires clear and testable etiological models that may translate into effective interventions. While alcohol intoxication and a pattern of heavy alcohol consumption are robust correlates of IPV perpetration, there has been limited research that examines the mediating mechanisms of how alcohol potentiates IPV. We provide a theoretical and methodological framework for researchers to conceptualize how alcohol intoxication causes IPV, and propose innovative laboratory methods that directly test mediational mechanisms. We conclude by discussing how these innovations may lead to the development of interventions to prevent or reduce alcohol-related IPV.

Inpatient aggression in community hospitals

Physical violence is a frequent occurrence in acute community psychiatry units worldwide. Violent acts by patients cause many direct injuries and significantly degrade quality of care. The most accurate tools for predicting near-term violence on acute units rely on current clinical features rather than demographic risk factors. The efficacy of risk assessment strategies to lower incidence of violence on acute units is unknown. A range of behavioral and psychopharmacologic treatments have been shown to reduce violence among psychiatric inpatients.

Benzodiazepine use and aggressive behaviour: a systematic review

CONTEXT

The relationship between benzodiazepine consumption and subsequent increases in aggressive behaviour in humans is not well understood.

OBJECTIVES

The current study aimed to identify, via a systematic review, whether there is an association between benzodiazepine consumption and aggressive responding in adults.

METHOD

A systematic review was conducted and reported in line with the PRISMA statement. English articles within MEDLINE, PsycARTICLES, PsycINFO, Academic Search Complete, and Psychology and Behavioural Sciences Collection databases were searched. Additional studies were identified by searching reference lists of reviewed articles. Only articles that explicitly investigated the relationship between benzodiazepine consumption and subsequent aggressive behaviour, or a lack thereof, in human adults were included.

RESULTS

Forty-six studies met the inclusion criteria. It was not possible to conduct a meta-analysis due to the heterogeneity of study design and benzodiazepine type and dose. An association between benzodiazepine use and subsequent aggressive behaviour was found in the majority of the more rigorous studies, although there is a paucity of high-quality research with clinical or forensic populations. Diazepam and alprazolam have received the most attention. Dose-related findings are inconsistent: therapeutic doses may be more likely to be associated with aggressive responding when administered as a once-off, whereas higher doses may be more risky following repeated administration. Trait levels of anxiety and hostility may indicate a vulnerability to the experience of benzodiazepine-related aggression.

CONCLUSIONS

There appears to be a moderate association between some benzodiazepines and subsequent aggressive behaviour in humans. The circumstances under which aggressive responding may be more likely to follow benzodiazepine use remain unclear, although some evidence suggests dose and/or personality factors may influence this effect.

Liquid courage or liquid fear: alcohol intoxication and anxiety facilitate physical aggression

Participants were 138 male social drinkers between 18 and 30 years of age from a university community in the southeastern United States in 2000. Trait and state anxiety was measured using the Trait Anxiety Inventory and the Facial Action Coding System, respectively. Participants consumed an alcoholic or nonalcoholic control beverage and completed a shock-based aggression task. Regression analysis indicated that alcohol-facilitated elevations in anxiety mediated the relation between alcohol consumption and aggression and that trait anxiety and physical provocation moderated this effect. Implications and limitations of this study are noted and future research directions are suggested.

Reduction of aggression during benzodiazepine withdrawal: effects of flumazenil

Benzodiazepine withdrawal has been associated with hostile and aggressive behavior. The benzodiazepine antagonist flumazenil has reduced, increased or not affected hostility and aggression in animal and human studies. In the present study we analyzed data collected in a placebo-controlled study of the effects of the benzodiazepine antagonist flumazenil in patients previously treated for benzodiazepine dependency, and healthy controls. The aim was to analyze the effects of flumazenil on hostility and aggression. Ten patients and 10 controls received, on two separate occasions, cumulative doses of flumazenil (0.05, 0.1, 0.25, 0.5 and 1mg at 15min intervals) or placebo. Withdrawal symptoms were rated after each injection. Patients had been free from benzodiazepines for 47 (4-266) weeks on the first occasion. A three-way interaction (groupxtreatmentxdose) was found, and was explained by: 1) patients rating aggression and hostility higher than controls at all times during placebo, while 2) during the flumazenil provocation i) the initial significant difference between patients and controls was no longer significant above the 0.5mg dose, and ii) patients rated aggression and hostility significantly lower above the 0.5mg dose compared to base-line. The results suggest that self-rated aggression and hostility in patients treated for benzodiazepine dependency was reduced by the partial benzodiazepine agonist flumazenil.