Effects of alcohol on cardiovascular reactivity and the mediation of aggressive behaviour in adult men and women

Reactive vs proactive aggression: A differential psychobiological profile? Conclusions derived from a systematic review

INTRODUCTION

Scholars have established subcategories of aggressive behavior in order to better understand this construct. Specifically, a classification based on motivational underpinnings makes it possible to differentiate between reactive and proactive aggression. Whereas reactive aggression is characterized by emotional lability, which means it is prone to impulsive reactions after provocation, proactive aggression is driven by low emotionality and high levels of instrumentality to obtain benefits. Some authors have conceived these two types as having a dichotomous nature, but others argue against this conceptualization, considering a complementary model more suitable. Hence, neuroscientific research might help to clarify discussions about their nature because biological markers do not present the same biases as psychological instruments.

AIM

The main objective of this study was to carry out a systematic review of studies that assess underlying biological markers (e.g., genes, brain, psychophysiological, and hormonal) of reactive and proactive aggression.

METHODS

To carry out this review, we followed PRISMA quality criteria for reviews, using five digital databases complemented by hand-searching.

RESULTS

The reading of 3993 abstracts led to the final inclusion of 157 papers that met all the inclusion criteria. The studies included allow us to conclude that heritability accounted for approximately 45% of the explained variance in both types of aggression, with 60% shared by both, especially, for overt and physical expression forms, and 10% specific to each type. Regarding allelic risk factors, whereas low functioning variants affecting serotonin transport and monoaminoxidase increased the risk of reactive aggression, high functioning variants were associated with proactive aggression. Furthermore, brain analysis revealed an overlap between the two types of aggression and alterations in the volume of the amygdala and temporal cortex. Moreover, high activation of the medial prefrontal cortex (PFC) facilitated proneness to both types of aggression equally. Whereas stimulation of the right ventrolateral (VLPFC) and dorsolateral (DLPFC) reduced proneness to aggression, inhibition of the left DLPFC increased it. Finally, psychophysiological and hormonal correlates in general did not clearly differentiate between the two types because they were equally related to each type (e.g., low basal cortisol and vagal variability in response to acute stress) CONCLUSIONS: This study reinforces the complementary model of both types of aggression instead of a dichotomous model. Additionally, this review also offers background about several treatments (i.e., pharmacological, non-invasive brain techniques…) to reduce aggression proneness.

The relationship between physiological reactivity to provocation and emotion dysregulation with proactive and reactive aggression

Biological theories of aggression propose that autonomic nervous system (ANS) hypo-reactivity may be more specific to proactive aggression, whereas ANS hyper-reactivity may be specific to reactive aggression. However, the research findings in this area are mixed. Furthermore, no study to date has examined whether emotion dysregulation moderates the aggression - ANS relationship. The present study examined electrodermal activity (EDA), respiratory sinus arrhythmia (RSA) and heart rate (HR) reactivity in 76-undergraduate participants (29 men, mean age = 21.49) in response to a provocation task relative to baseline. Results showed that blunted HR reactivity was associated with increased proactive aggression. RSA augmentation and blunted EDA reactivity were both associated with increased proactive and reactive aggression, but only among those above the sample mean on emotion dysregulation. Thus, emotion dysregulation may play a key role in the relationship between ANS reactivity and both reactive and proactive aggression.

A Biobehavioral Validation of the Taylor Aggression Paradigm in Female Adolescents

This research assessed the behavioral, emotional, endocrinological and autonomic reactivity to the laboratory Taylor Aggression Paradigm (TAP) in a sample of healthy female adolescents. Twenty participants were induced with the TAP to behave aggressively (aggression group) and 20 age-matched participants were not induced to behave aggressively (control group). Regression analysis revealed that the aggression group displayed significant higher levels of aggressive behavior compared to the control group (χ² (2) = 255.50, p < 0.0001). Aggressive behavior was not related to self-reported measures of trait aggression, impulsiveness or psychopathy features. Regarding the biological responses, regression analysis on cortisol, missed the set level of significance (χ² (1) = 3.73, p = 0.054), but showed significant effects on heart rate as a function of aggression induction (χ² (1) = 5.81, p = 0.016). While aggression induction was associated with increased autonomic arousal (heart rate), the interpretation of the effects on cortisol warrant caution, given existing differences between groups at baseline and overly elevated cortisol attributable to the general experimental procedures and not the TAP per se. No differences were found with respect to testosterone. In summary, the present study lends preliminary support for the validity of the TAP and its use in female adolescents on a behavioral and autonomic level.

Provocation and target gender as moderators of the relationship between acute alcohol use and female perpetrated aggression

Acute alcohol use appears to exert a small but significant effect on female perpetrated aggression in the laboratory but there has been no effort to evaluate comprehensively the situational moderators of this relationship. This preliminary review was intended to explore the moderating effects of provocation and target gender on alcohol-related aggression among females in this understudied area of research. Moderator analyses were conducted on 14 studies. Despite limitations imposed by the sparsity of laboratory based research on alcohol-related aggression among females, initial results suggest that alcohol may exert stronger effects over female aggression following high (d = 0.25, k = 8, p < .01, 95% CI = 0.10-0.40) rather than low (d = -0.07, k = 6, p = .52, 95% CI = -0.29-0.15) provocation and when targets of aggression are female (d = 0.19, k = 9, p = .01, 95% CI = 0.04-0.34) rather than male (d = -0.06, k = 4, p = .61, 95% CI = -0.30-0.18). Results offer initial insight into situational risk factors pertinent to research and treatment of alcohol-related aggression among females while serving as an impetus for future research in this critical, neglected area of study.

Aggression in Women: Behavior, Brain and Hormones

We review the literature on aggression in women with an emphasis on laboratory experimentation and hormonal and brain mechanisms. Women tend to engage in more indirect forms of aggression (e.g., spreading rumors) than other types of aggression. In laboratory studies, women are less aggressive than men, but provocation attenuates this difference. In the real world, women are just as likely to aggress against their romantic partner as men are, but men cause more serious physical and psychological harm. A very small minority of women are also sexually violent. Women are susceptible to alcohol-related aggression, but this type of aggression may be limited to women high in trait aggression. Fear of being harmed is a robust inhibitor of direct aggression in women. There are too few studies and most are underpowered to detect unique neural mechanisms associated with aggression in women. Testosterone shows the same small, positive relationship with aggression in women as in men. The role of cortisol is unclear, although some evidence suggests that women who are high in testosterone and low in cortisol show heightened aggression. Under some circumstances, oxytocin may increase aggression by enhancing reactivity to provocation and simultaneously lowering perceptions of danger that normally inhibit many women from retaliating. There is some evidence that high levels of estradiol and progesterone are associated with low levels of aggression. We highlight that more gender-specific theory-driven hypothesis testing is needed with larger samples of women and aggression paradigms relevant to women.

The proximal effects of acute alcohol use on female aggression: A meta-analytic review of the experimental literature

Experimental research on alcohol-related aggression has focused largely upon male participants, providing only a limited understanding of the proximal effects of acute alcohol use on aggression among females extrapolated from the male literature. The current meta-analysis was undertaken to summarize the effects of alcohol, compared to placebo or no alcohol, on female aggression as observed across experimental investigations. A review of the literature yielded 11 articles and 12 effect sizes for further analysis. The overall effect size of alcohol on female aggression was small and reached statistical significance (d = .17, p = .02, 95% confidence interval [.03, .30]). Meta-analytic examination of the experimental literature indicated that alcohol is a significant factor in female aggression. The overall alcohol-aggression effect was smaller than has been observed among male samples. Additional research is required to evaluate the influence of other factors on alcohol-related aggressive responding among female participants. (PsycINFO Database Record

An event-level examination of sex differences and subjective intoxication in alcohol-related aggression

Laboratory-based experimental research has demonstrated that the pharmacological effects of alcohol can increase aggressive responding. Given mixed findings and concerns regarding task validity, however, it remains uncertain whether this effect holds constant across men and women and whether variability in subjective alcohol intoxication contributes to alcohol-related aggression. In this investigation, the authors used 4 years of event-level data in a sample of 1,775 college students (140,618 total observations) to provide a test of laboratory-derived findings on the link between alcohol and aggression in an alternative methodology. They found support for several such findings: (a) Within-person increases in alcohol intoxication, as assessed by estimated blood alcohol concentrations (eBACs), were associated with increases in the probability of aggression at the drinking-episode level; (b) this association was significantly stronger among men than among women; and (c) within-person variability and between-persons individual differences in levels of subjective alcohol intoxication were associated with aggression over and beyond eBACs. Cross-methodological replication can reduce the impact of constraints specific to experimental studies on conclusions regarding alcohol's relation with aggression.

Cognitive and neurobiological mechanisms of alcohol-related aggression

Alcohol-related violence is a serious and common social problem. Moreover, violent behaviour is much more common in alcohol-dependent individuals. Animal experiments and human studies have provided insights into the acute effect of alcohol on aggressive behaviour and into common factors underlying acute and chronic alcohol intake and aggression. These studies have shown that environmental factors, such as early-life stress, interact with genetic variations in serotonin-related genes that affect serotonergic and GABAergic neurotransmission. This leads to increased amygdala activity and impaired prefrontal function that, together, predispose to both increased alcohol intake and impulsive aggression. In addition, acute and chronic alcohol intake can further impair executive control and thereby facilitate aggressive behaviour.

Heart rate stress response dampening: the impact of alcohol, family history, and gender on at risk children and siblings

OBJECTIVE

In the following study we tested the stress response dampening (SRD) model which postulates that stress responses are more likely to be attenuated by alcohol in individuals at risk for alcohol dependence than in persons without that risk. In a laboratory experiment we examined a) if SRD effects exist for both sons and healthy daughters of alcohol dependent fathers, and b) if SRD effects exist for siblings of alcohol dependent males.

METHODS

We recruited 104 subjects at risk and 51 matched control subjects. In a laboratory experiment, study subjects received alcohol in one of two laboratory sessions and a stress paradigm served to elicit heart rate stress responses.

RESULTS

Heart rate stress responses were attenuated by alcohol in female family history positive (FHP) and female family history negative (FHN) subjects, however not in males. A multiple regression analysis revealed "Heart Rate Stress Response in the Non-Alcohol Condition" and "Blood Alcohol Level" as significant predictors of SRD.

CONCLUSIONS

According to our findings, females carry a distinct risk for developing alcohol dependence, regardless of their family history and regardless of their degree of familial relationship. This is an important issue for devising models concerning the development and maintenance of alcohol dependence in females. The study extends the current research literature, which mainly focuses on male subjects at risk, by including female subjects at risk, as well as siblings at risk of both genders.

Increases in B-type natriuretic peptide after acute mental stress in heart failure patients are associated with alcohol consumption

OBJECTIVE

The aim of this study was to investigate in heart failure (HF) patients whether acute mental stress induces increases in the HF-severity biomarker B-type natriuretic peptide (BNP) and if alcohol consumption is associated with such stress-induced increases.

METHOD

Twenty-one male HF patients and 19 male non-HF controls (M = 56 years, SEM = 2) underwent a 15-minute acute mental stress test combining public speaking and mental arithmetic. Plasma levels of BNP were determined immediately before as well as 2 hours after the stress test. Alcohol consumption was assessed by self-reported number of drinks per month and history of use.

RESULTS

HF patients had higher BNP levels before and after stress, F(1, 38) = 23.42, p < .001, and showed greater stress-induced increases in BNP levels, F(1, 38) = 4.52, p = .04, compared with controls. HF status (beta = .32, p = .015, deltaR(2) = .10) and higher alcohol consumption ((beta = .61, p< .001, deltaR(2) = .37) were independently associated with higher BNP stress increases. Moreover, higher alcohol consumption moderated the greater BNP stress increases in HF patients but not in controls (p = .49, p < .001, delta(2) = .20), although alcohol consumption did not differ between groups.

CONCLUSIONS

For individuals with HF, particularly those who drink moderate to more substantial amounts of alcohol, exposure to acute psychological stress leads to increases in circulating levels of BNP, a biomarker which is associated with increased morbidity and mortality in HF.

Gender differences in acute alcohol effects on self-regulation of arousal in response to emotional and alcohol-related picture cues

Basic mechanisms through which men and women self-regulate arousal have received little attention in human experimental addiction research, although stress-response-dampening and craving theories suggest an important role of emotional arousal in motivating alcohol use. This study examined gender differences in the effects of acute alcohol intoxication on psychophysiological and self-reported arousal in response to emotionally negative, positive, and neutral, and alcohol-related, picture cues. Thirty-six social drinkers (16 women) were randomly assigned to an alcohol, placebo, or control beverage group and exposed to picture cues every 10 s (0.1 Hz presentation frequency). Psychophysiological arousal was assessed via a 0.1-Hz heart rate variability (HRV) index. A statistically significant beverage group-by-gender interaction effect on psychophysiological, but not self-reported, arousal was found. The 0.1-Hz HRV responses to picture cues were suppressed by alcohol only in men. This gender-specific suppression pattern did not differ significantly across picture cue types. There were no significant gender differences in the placebo or control group. Greater dampening of arousal by alcohol intoxication in men, compared with women, may contribute to men's greater tendency to use alcohol to cope with stress.

Telescoped trajectories from alcohol initiation to disorder in children of alcoholic parents

The current study tested whether and why children of alcoholics (COAs) showed telescoped (adolescent) drinking initiation-to-disorder trajectories as compared with non-COAs. Using longitudinal data from a community-based sample, the authors confirmed through survival analyses that COAs progressed more quickly from initial adolescent alcohol use to the onset of disorder than do matched controls. Similar risks for telescoping were evident in COAs whose parents were actively symptomatic versus those whose parents had been previously diagnosed. Stronger telescoping effects were observed for COAs whose parents showed comorbidity for either depression or antisocial personality disorder. Both greater externalizing symptoms and more frequent, heavier drinking patterns at initiation failed to explain COAs' risk for telescoping, although externalizing symptoms were a unique predictor of telescoping. This risk for telescoping was also evident for drug disorders. These findings characterize a risky course of drinking in COAs and raise important questions concerning the underlying mechanisms and consequences of telescoping in COAs.

Risk factors for alcohol misuse: examining heart rate reactivity to alcohol, alcohol sensitivity, and personality constructs

OBJECTIVE

Heart rate reactivity to alcohol has been conceptualized as an index of alcohol-induced reward and has been associated with a sensation seeking personality profile. The goal of this study is to expand on previous findings regarding the significance of heart rate reactivity to alcohol while examining convergent lines of research on alcohol sensitivity, the rewarding effects of alcohol, and personality constructs.

METHODS

Participants (N=47) were heavy drinkers who completed an intravenous alcohol challenge protocol.

RESULTS

Analyses revealed a significant negative relationship between heart rate reactivity and alcohol-induced sedation and subjective intoxication. Heart rate reactivity was positively related to self-reported alcohol-induced vigor and to impulsivity and sensation seeking scores.

CONCLUSIONS

Taken together, these results suggest that individuals with heightened heart rate reactivity to alcohol appear to be more sensitive to the invigorating properties of alcohol, while being less sensitive to the sedative and unpleasant effects of alcohol intoxication. These findings have implications to the conceptualization of heart rate reactivity to alcohol as a biobehavioral marker of alcohol sensitivity.

Influence of Subjective Intoxication, Breath Alcohol Concentration, and Expectancies on the Alcohol-Aggression Relation

BACKGROUND

The purpose of this study was to investigate the influence of subjective intoxication, alcohol-aggression expectancies, and breath alcohol concentration (BrAC) on intoxicated aggression in men and women while controlling for dispositional aggressivity.

METHODS

Subjects were 328 (163 men and 165 women) healthy social drinkers between 21 and 35 years of age. Following the consumption of either an alcohol or an active placebo beverage, subjects were tested on a modified version of the Taylor Aggression Paradigm in which mild electric shocks were received from, and administered to, a fictitious opponent during a competitive task. Levels of subjective intoxication and BrAC were measured immediately before subjects began the aggression task. Aggressive behavior was operationalized as the shock intensities administered to the fictitious opponent under conditions of low and high provocation.

RESULTS

Subjective intoxication ratings were not related to aggressive behavior for either men or women. Alcohol-aggression expectancies were related to aggression for men, but this effect was rendered nonsignificant when controlling for dispositional aggressivity, which in turn, was significantly related to the dependent variables for both men and women. Finally, BrAC was also related to aggression above and beyond the effects of dispositional aggressivity, yet only for men.

CONCLUSIONS

Taken as a whole, this study suggests that intoxicated aggression is primarily the result of alcohol's pharmacological properties in conjunction with an aggressive disposition.

Alcohol and Aggression Without Consumption. Alcohol Cues, Aggressive Thoughts, and Hostile Perception Bias

Researchers and the lay public have long known of a link between alcohol and aggression. However, whether this link results from alcohol's pharmacological effects or is merely an artifact of the belief that alcohol has been consumed (i.e., placebo effect) has been debated. The current experiments examined the propensity for alcohol-related cues to elicit aggressive thoughts and hostile perceptions in the absence of alcohol or placebo consumption. In Experiment 1, participants made faster lexical decisions concerning aggression-related words following alcohol-related primes compared with neutral primes. In Experiment 2, participants who first were exposed to alcohol advertisements subsequently rated the behavior of a target person as more hostile than participants who initially viewed control advertisements. Furthermore, this effect was largest among participants who most strongly associated alcohol and aggression. Findings are discussed in terms of semantic network theory and links in memory between alcohol and its anticipated effects.

Differential effects of past-year stimulant and sedative drug use on alcohol-related aggression

The goals of this study were to determine the effects of past-year stimulant and sedative drug use on alcohol-related aggression and to examine whether the relation between stimulant drug use and intoxicated aggression is better accounted for by behavioral disinhibition. Participants were 330 healthy social drinkers (164 men and 166 women) between 21 and 35 years of age. Past-year stimulant and sedative use and behavioral disinhibition were assessed via self-report questionnaires. Following the consumption of either an alcohol or a placebo beverage, participants were tested on a modified version of the Taylor Aggression Paradigm [Taylor, S. (1967). Aggressive behavior and physiological arousal as a function of provocation and the tendency to inhibit aggression. Journal of Personality, 35, 297-310] in which mild electric shocks were received from, and administered to, a fictitious opponent. Aggressive behavior was operationalized as the shock intensities administered to the fictitious opponent under conditions of low and high provocation. Results indicated that alcohol significantly strengthened the relation between stimulant drug use and aggression, but only among men. Behavioral disinhibition did not account for this effect. Regardless of past-year drug use, alcohol did not facilitate aggression among women. The present findings suggest that stimulant drug use may be a risk factor for intoxicated aggression for men. However, the underlying mechanisms accounting for this effect remain unclear.

Executive functioning and alcohol-related aggression

The primary goal of this investigation was to determine whether executive functioning (EF) would moderate the alcohol-aggression relation. Participants were 310 (152 men and 158 women) healthy social drinkers between 21 and 35 years of age. EF as well as non-EF skills were measured with 13 validated neuropsychological tests. Following the consumption of either an alcoholic or a placebo beverage, participants were tested on a modified version of the Taylor Aggression Paradigm (S. Taylor, 1967), in which mild electric shocks were received from, and administered to, a fictitious opponent. Aggressive behavior was operationalized as the shock intensities administered to the fictitious opponent. EF was negatively related to aggressive behavior for men, regardless of beverage group, even when controlling for non-EF skills. Furthermore, alcohol increased aggression only for men with lower EF scores. Finally, the mere belief that alcohol was consumed suppressed aggression for women but not for men.

The effects of affective, behavioral, and cognitive components of trait anger on the alcohol-aggression relation

OBJECTIVE

The purpose of this study was to investigate the effects of affective, behavioral, and cognitive components of trait anger on alcohol-related aggression in men and women.

METHODS

Subjects were 300 (150 men and 150 women) healthy social drinkers between 21 and 35 years of age. Trait anger was measured using the ABC Anger Inventory. Following the consumption of either an alcohol or a placebo beverage, subjects were tested on a modified version of the Taylor Aggression Paradigm in which mild electric shocks were received from, and administered to, a fictitious opponent during a competitive task. Aggressive behavior was operationalized as the shock intensities administered to the fictitious opponent under conditions of low and high provocation.

RESULTS

Results indicated that alcohol increased aggression only for men with higher behavioral and cognitive anger scores and only for women with higher behavioral anger scores. Results also showed that when all anger components were taken into account, behavioral anger was the only factor that put one at risk for intoxicated aggression.

CONCLUSIONS

Two recent studies demonstrated that the trait of "general" anger is a risk factor for intoxicated aggression (Giancola, 2002a; Parrott and Zeichner, 2002). The present investigation confirmed and extended these findings by examining the role of three different components of anger. The results highlight the fact that alcohol consumption does not increase aggression in all persons and in all situations. An important goal for future research is to identify which individual difference and contextual factors are most important in determining who will, and will not, behave in an aggressive manner when intoxicated.

Difficult temperament, acute alcohol intoxication, and aggressive behavior

The purpose of this study was to investigate the influence of a difficult temperament on alcohol-related aggression in men and women. Subjects were 330 (164 men and 166 women) healthy social drinkers between 21 and 35 years of age. Temperament was measured using the dimensions of temperament survey-revised (DOTS-R). Following the consumption of either an alcohol or a placebo beverage, subjects were tested on a modified version of the Taylor aggression paradigm in which mild electric shocks were received from, and administered to, a fictitious opponent during a competitive task. Aggressive behavior was operationalized as the shock intensities administered to the fictitious opponent under conditions of low and high provocation. Of all the variables, provocation was the strongest elicitor of aggression. Overall, a difficult temperament was positively related to the aggression for all subjects. The finding of greatest importance was that alcohol only increased aggression for men with a difficult temperament. The results highlight the fact that alcohol consumption does not increase aggression in all persons and in all situations. An important goal for future research is to identify which individual difference and which contextual factors are most important in determining who will, and who will not, behave in an aggressive manner when intoxicated.

Drugs of abuse and the elicitation of human aggressive behavior

The drug-violence relationship exists for several reasons, some direct (drugs pharmacologically inducing violence) and some indirect (violence occurring in order to attain drugs). Moreover, the nature of that relationship is often complex, with intoxication, neurotoxic, and withdrawal effects often being confused and/or confounded. This paper reviews the existing literature regarding the extent to which various drugs of abuse may be directly associated with heightened interpersonal violence. Alcohol is clearly the drug with the most evidence to support a direct intoxication-violence relationship. The literatures concerning benzodiazepines, opiates, psychostimulants, and phencyclidine (PCP) are idiosyncratic but suggest that personality factors may be as (or more) important than pharmacological ones. Cannabis reduces likelihood of violence during intoxication, but mounting evidence associates withdrawal with aggressivity. The literature on the relationship between steroids and aggression is largely confounded, and between 3,4-methylenedioxymethamphetamine (MDMA) and aggression insufficient to draw any reasonable conclusions. Conclusions and policy implications are briefly discussed.