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. D

Child maltreatment has been consistently linked to aggression, yet there have been few attempts to conceptualize precisely how maltreatment influences the development of aggression. This review proposes that biases in cognitive, emotional, and neurobiological development mediate the relation between childhood maltreatment and the development of aggression. In addition, it is posited that physical abuse and neglect may have differential effects on development: Physical abuse may result in hypervigilance to threat and a hostile attributional bias, whereas neglect may result in difficulties with emotion regulation because of a lack of emotional interactions. These processes may be "hardwired" into neural networks via the overactivation of certain brain regions and dysfunctional cognitive processes. The theoretical and necessarily speculative nature of this article is intended to stimulate hypotheses for future research. Only when the adverse effects of maltreatment on brain and cognitive development are understood can scholars hope to develop more effective interventions to alter the developmental pathway to aggression.

Violence is a social problem that carries enormous costs; however, our understanding of its etiology is quite limited. A large body of research exists, which suggests a relationship between abnormalities of the frontal lobe and aggression; as a result, many researchers have implicated deficits in so-called "executive function" as an antecedent to aggressive behaviour. Another possibility is that violence may be related to problems interpreting facial expressions of emotion, a deficit associated with many forms of psychopathology, and an ability linked to the prefrontal cortex. The current study investigated performance on measures of executive function and on a facial-affect recognition task in 20 violent offenders, 20 non-violent offenders, and 20 controls. In support of our hypotheses, both offender groups performed significantly more poorly on measures of executive function relative to controls. In addition, violent offenders were significantly poorer on the facial-affect recognition task than either of the other two groups. Interestingly, scores on these measures were significantly correlated, with executive deficits associated with difficulties accurately interpreting facial affect. The implications of these results are discussed in terms of a broader understanding of violent behaviour.

A large body of research has documented a relation between the executive cognitive functions (ECFs) and interpersonal aggressive behavior. A predominant theory proposes that individuals with poor ECFs are more aggressive because they are unable to inhibit impulsive behaviors. However, evidence for this relationship is typically indirect. In this study, 46 healthy men and women completed measures of ECF, the Taylor Aggression Paradigm, and the Go/No-Go discrimination task, a behavioral measure of impulsivity. Also, impulsiveness of participant responses during the aggression task was directly assessed by measuring latency of responses to provocation (''set-time''). It was hypothesized that lowquartile-scoring ECF men and women would perform more aggressively and more impulsively than high-quartile peers. Consistent with expectations, results indicated that ECF was related to aggression and to impulsivity on the Go/No-Go task. However, low-ECF men and women did not have shorter settimes; in fact, on this task, low-ECF participants' behavioral decisions seemed slightly slower than those of high-ECF participants. In light of these results, the authors speculate that a social informationprocessing problem may mediate the ECF aggression relationship rather than altered impulsivity per se.

Our results support the conclusion that alcohol negatively affects cognitive performance and has a differential effect on the descending versus the ascending limb of the blood alcohol concentration curve. The latter finding may have important ramifications relating to the detrimental consequences of alcohol intoxication.

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The adverse consequences of violence on society are tremendous. The proportion of offenders incarcerated for violent offenses is large, and the cost of keeping these offenders incarcerated is startling. Understanding and treating the causal underpinnings of violent crime is of utmost importance for individuals and society as a whole. Several factors have been identified as potential contributors to violent crime, including cognitive deficits in executive functioning [Hoaken et al., 2007]. To investigate this further, 77 offenders from Fenbrook Institution, a federal facility, were tested on a battery of executive functioning measures. Offenders were found to have broad and pervasive dysfunction in their executive abilities. In addition, specific scores from the battery were found using regression techniques, to predict the frequency and severity of past violent offending but not nonviolent offending. This speaks of the possibility of a new type of correctional rehabilitation program, one that focuses on the rehabilitation of basic executive functions.

A considerable literature, clinical and experimental, has demonstrated the aggression-eliciting effects of alcohol intoxication. However, the focus of the experimental literature has been primarily on men and the studies on women have been inconclusive. This study was conducted to test for possible gender differences in the manifestation of alcohol-induced aggression. Participants were 54 males and 60 females, aged 18-30 years, who competed in a competitive aggression paradigm either sober or intoxicated. As expected, intoxicated men were more aggressive than their sober peers. However, under high provocation, both sober and intoxicated, women manifested aggression comparable to the intoxicated men. This study suggests that women can be as aggressive as men, and that alcohol intoxication does not seem to be as important a determining factor.