Drugs of abuse and the elicitation of human aggressive behavior

Genetic inactivation of the CRF2 receptor eliminates morphine-induced sociability deficits in female mice

Social behavior deficits, such as poor sociability and social isolation, are key clinical features of substance use disorders. The corticotropin-releasing factor (CRF) system may underlie the effects of substances of abuse but its implication in substance-induced social behavior deficits remains largely unknown. CRF signaling is mediated by two receptor types, termed CRF1 and CRF2. Using the genetic mouse model of CRF2 receptor-deficiency and the three-chamber task for sociability, the present studies examined the specific role for the CRF2 receptor in sociability deficits induced by morphine. Notably, to assess possible sex-linked differences, female and male CRF2 receptor wild-type (CRF2 WT) or knockout (CRF2 KO) mice were used. Intraperitoneal administration of morphine (1 mg/kg) reliably eliminated the preference for an unfamiliar same-sex conspecific over an object in female CRF2 WT, but not in CRF2 KO, mice, revealing a key role for the CRF2 receptor in opiate-induced sociability deficits. In contrast, morphine almost significantly and similarly reduced the preference for an unfamiliar same-sex conspecific over an object in male CRF2 WT and CRF2 KO mice, indicating no role for the CRF2 receptor. Notably, treatment with morphine never affected distance travelled during the three-chamber test, indicating that CRF2 receptor-dependent or -independent opiate effects were specific to social behavior. The present findings provide initial evidence of a critical sex-linked role for the CRF2 receptor in social behavior deficits induced by opiate substances, suggesting new, sex-customized, therapeutic strategy for opioid use disorders.

Global burden and trend of substance use disorders, self-harm, and interpersonal violence from 1990 to 2021, with projection to 2040

BACKGROUND

Alcohol use disorders (AUD), drug use disorders (DUD), interpersonal violence, and self-harm are a major public health concern globally, with high rates of disability, morbidity, and mortality associated with this. This study aims to estimate the disease burden, trends, projections, and disparities of AUD, DUD, interpersonal violence, and self-harm among all ages and sexes from 1990 to 2021.

METHODS

This study is a secondary analysis utilizing data from the Global Burden of Disease (GBD) 2021 in 204 countries and territories. The incidence, deaths, and disability-adjusted life years (DALYs), projection, and the inequality were estimated for AUD, DUD, interpersonal violence, and self-harm among all age and sex.

RESULTS

In 2021, there were 55.78 (46.56-64.31) million new cases of AUD, 13.61 (11.63-15.67) million new cases of DUD, 29.40 (26.17-32.65) million new cases of interpersonal violence, 5.49 (4.6-6.5) million new cases of self-harm globally. By 2040, AUD is forecasted to be 51.98 (29-74.97) million, DUD will be 13.81 (9.23-18.39) million, 36.01 (15.25-56.78) million for interpersonal violence, and 10.55 (3.16-17.94) million for self-harm. In terms of gender and age distribution, males had higher incidence, mortality, and DALYs for AUD, DUD, and interpersonal violence compared to females. Females had higher incidence of self-harm, while males had higher mortality. By age group, individuals aged 15-49 bore the highest burden of DUD, interpersonal violence, and self-harm, while those aged 50-74 had the highest burden of AUD. The burden of these conditions is closely related to the socio-demographic index (SDI). High- and middle-high SDI regions had a heavier burden of AUD, DUD, and self-harm, while low- and middle-low SDI regions had a heavier burden of interpersonal violence. Additionally, from 1990 to 2021, health inequalities for AUD and self-harm decreased, while those for DUD and interpersonal violence increased.

CONCLUSIONS

From 1990 to 2021, the disease burden of AUD, DUD, interpersonal violence, and self-harm exhibited specific patterns across different genders, age groups, and regions. Multilevel interventions should be initiated, with a focus on reducing inequalities through resource allocation and policy support.

Suicidal risk in patients with aggression in schizophrenia: a systematic review

Introduction

Suicide represents the primary risk factor for mortality among individuals diagnosed with schizophrenia, with a mortality rate that is 10 times higher than that observed in the general population. In the study of individuals who have committed suicide, some exhibited a high risk of aggression and impulsivity, which permitted the consideration of these indicators as predictors of suicide risk. The extant literature contains a number of debates concerning diverse conceptualizations of aggression and impulsivity in the context of suicidal behavior. The present study examined the levels of verbal and physical aggression in individuals diagnosed with schizophrenia, finding that 43% exhibited verbal aggression and 24% physical aggression, levels that are significantly higher than those observed in the general population. Concurrently, an analysis of the psycho-emotional state of patients with suicidal behavior in the anamnesis reveals an indication that the suppression of emotions (including aggression) and the avoidance of harm may result in suicide. This finding is at odds with the previously mentioned results, and consequently, the present review sought to assess the impact of aggressive behavior on suicide risk in patients diagnosed with schizophrenia.

Methods

The search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The literature search was conducted in PubMed, Cochrane Library, PsychINFO and Mendeley Data. The search terms used were "aggress*" and "suicid*" or "autoaggress*" and "schizophrenia*". The search was limited to papers published between 2009 and 2024 (the last 15 years), and the search was continued until November 2024. This systematic review has been registered in PROSPERO (CRD42024628033).

Results

A total of 1,364 articles were identified, 295 of which were duplicates. Following a thorough review, 1,046 articles that did not align with the title and abstract were excluded from the analysis. During the literature search, 23 articles were read in full, of which eight studies met the inclusion criteria. A total of eight studies provided information on the effect of aggressive behavior on suicide in patients with schizophrenia. Of these, six studies demonstrated a positive association between aggression and suicidal behavior or employed a logistic regression model in which the risk of aggression increased the risk of suicide and vice versa. Conversely, two studies revealed no association between suicide risk and aggression.

Conclusions

Patients with a documented history of suicide attempts and aggressive behavior are considered to be at risk of suicide, thus emphasizing the necessity for preventive measures to be implemented for this cohort of patients. However, the conclusion regarding the influence of aggressive behavior on increased suicide risk may not be entirely accurate and may not reflect the true extent of the problem, due to the significant number of methodological inaccuracies and discrepancies in the design of the studies included in the review.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024628033, identifier CRD42024628033.

Recent research involving consent, alcohol intoxication, and memory: Implications for expert testimony in sexual assault cases

When adjudicating sexual assault cases, it is imperative that attorneys are educated on the incident characteristics relevant to their case and that expert witnesses are prepared to consult and/or testify regarding relevant science. Most reported sexual assault cases occur when at least one of the relevant parties has consumed alcohol, which has neurochemical, behavioral, psychological, and cognitive effects that are important to consider relative to the facts of the case. Nearly a decade ago, Connell (2015) provided an overview of research relevant to an expert witness's role in these types of cases. In the current review, we extend Connell's (2015) work by examining recent research examining alcohol intoxication and memory. We also expand our review to include current research examining alcohol use in voluntary sexual behavior and issues of sexual consent, as it provides both a legal and conceptual framework for the discussion of sexual assault crimes. The goal of the review is to highlight implications of the scientific research on legal decision-making and potential expert testimony.

The effects of transcranial direct current stimulation over the ventromedial prefrontal cortex on reactive aggression in intoxicated and sober individuals

Alcohol-related aggression is a widely observed phenomenon that has detrimental effects on both individuals and society, putatively caused by dysfunction in the prefrontal cortex. The ventromedial prefrontal cortex (vmPFC) plays a critical role in representing the reward value of future actions. Emerging research has suggested that transcranial direct current stimulation (tDCS) over the vmPFC can reduce aggression. However, no study has examined whether tDCS can mitigate intoxicated aggression. In this study, 153 healthy participants consumed alcohol or not and completed the anger-infused Ultimatum Game with simultaneous double-blind anodal tDCS or sham over the bilateral vmPFC. For participants in the anodal tDCS condition, intoxicated participants were less aggressive than sober participants when insulted. However, among sober participants, anodal tDCS increased aggression. For participants in the alcohol condition, we observed no differences in aggression between the anodal tDCS and the sham tDCS conditions. These findings provide mixed support for tDCS as a means to attenuate intoxicated aggression.

National and regional prevalence of interpersonal violence from others' alcohol use: a systematic review and modelling study

Background

While alcohol use is an established risk factor for interpersonal violence, the extent to which people are affected by interpersonal violence from others' drinking has not yet been quantified for different world regions. This modelling study aims to provide the first estimates of the national and regional prevalence of interpersonal violence from others' drinking.

Methods

An international systematic literature search (02/28/2023, Prospero: CRD42022337364) was conducted to identify general adult population studies assessing the prevalence of interpersonal violence from others' drinking with no restrictions to publication date or language. Reports that did not provide data on interpersonal violence from others' drinking (primary outcome), were no original research studies, or captured a selected group of people only, were excluded. Observed prevalence data were extracted and used to build fractional response regression models to predict past-year prevalence of emotional and physical violence from others' drinking in 2019. Random-effects meta-regression models were used to aggregate the observed prevalence of sexual and intimate partner violence. Study risk of bias (ROB) was assessed using a modified version of the Newcastle-Ottawa Scale.

Findings

Out of 13,835 identified reports, 50 were included covering just under 830,000 individuals (women: 347,112; men: 322,331; men/women combined: 160,057) from 61 countries. With an average prevalence of 16·8% (95% CI: 15·2-18·3%) and 28·3% (95% CI: 23·9-32·4%) in men and women combined in the GBD super regions High Income and Central Europe, Eastern Europe, & Central Asia, respectively, emotional violence was the most common form of interpersonal violence from others' drinking. Physical violence averaged around 3% (women) and 5% (men) in both regions. The pooled prevalence of sexual violence from others' drinking in men and women was 1·3% (95% CI: 0·5-3·3%, 95% PI: 0·1-16·9%) and 3·4% (95% CI: 1·4-8·3%, 95% PI: 0·2-35·3%), respectively, and ranged between 0·4% (95% CI: 0·1-1·6%, 95% PI: 0·0-7·3%) and 2·7% (95% CI: 1·1-6·3%, 95% PI: 0·2-30·0%) for different forms of intimate partner violence. ROB was moderate or critical for most reports; accounting for critical ROB did not substantially alter our results.

Interpretation

The share of the population experiencing harms from others' drinking is significant and should be an integral part of public health strategies.

Funding

Research reported in this publication was supported by the Canadian Institutes of Health Research (CIHR; grant: CIHR FRN 477887).

Global burden of self-harm and interpersonal violence and influencing factors study 1990-2019: analysis of the global burden of disease study

INTRODUCTION

Widespread concern exists in today's world regarding self-harm and interpersonal violence. This study to analyze the changes in temporal trends and spatial patterns of risk factors and burdens of self-harm and interpersonal violence using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.

METHODS

Temporal trends in self-harm and interpersonal violence were initially summarized using the estimated annual percentage change (EAPC). Data were compiled and visualized to delineate changes in disease burden and factors influencing self-harm and interpersonal violence from 1990 to 2019, stratified by gender, age and GBD region.

RESULTS

In 2019, the DALY rates of self-harm were 424.7(95% UI 383.25, 466.93). Over the period from 1999 to 2019, self-harm exhibited an overall decreasing trend, with the EAPC of -1.5351 (95% CI -1.6194, -1.4507), -2.0205 (95% CI -2.166, -1.8740) and -2.0605 (95% CI -2.2089, -1.9119), respectively. In contrast, the incidence rate of interpersonal violence was significantly higher than self-harm, with a rate of 413.44 (95% UI 329.88, 502.37) per 100,000 population. Mortality and DALYs of interpersonal violence were lower than those of self-harm, at 5.22 (95% UI 4.87, 5.63) and 342.43 (95% UI 316.61, 371.55). Disease burden of self-harm and interpersonal violence varied by gender, age groups and region. Specific risk factors showed that alcohol use, high temperature and drug use were the main risk factors for self-harm, while alcohol use, intimate partner violence and high temperature were associated with interpersonal violence. Low temperature was a common protective factor for both self-harm and interpersonal violence. The burden of self-harm and interpersonal violence was attributed to different factors influences in different SDI regions.

CONCLUSIONS

The study explored temporal trends and spatial distribution of the global disease burden of self-harm and interpersonal violence, emphasizing the significant impact of factors such as alcohol use, temperature, and drug use on disease burden. Further research and policy actions are needed to interpret recent changes of disease burden of self-harm and interpersonal violence, and dedicated efforts should be implemented to devise evidence-based interventions and policies to curtail risk factors and protect high-risk groups.

Is There a Dose-Response Relationship Between Cannabis Use and Violence? A Longitudinal Study in Individuals with Severe Mental Disorders

Introduction: Recent longitudinal studies point toward the existence of a positive relationship between cannabis use and violence in people with severe mental disorders (SMD). However, the existence of a dose-response relationship between the frequency/severity of cannabis use and violence has seldom been investigated. Therefore, this study aims to determine if such a relationship exists in a psychiatric population. Methods: To do so, a total of 98 outpatients (81 males and 17 females, all over 18 years of age) with SMD were recruited at the Institut universitaire de santé mentale de Montréal (Montréal, Canada) and included in the analyses. Clinical evaluations were conducted every 3 months for a year. Substance use, violent behaviors, and potential covariables were assessed through self-reported assessments, urinary testing, as well as clinical, criminal, and police records. Using generalized estimating equations, the association between cannabis use frequency (nonusers, occasional, regular, and frequent users) and violence was investigated, as well as the association between the severity of cannabis use and violent behaviors. Results: It was found that cannabis use frequency and severity were significant predictors of violent behaviors. After adjustment for time, age, sex, ethnicity, diagnoses, impulsivity, and use of alcohol and stimulants, odds ratios were of 1.91 (p<0.001) between each frequency profile and 1.040 (p<0.001) for each increase of one point of the severity of cannabis use score (ranging from 0 to 79). Conclusions: Despite the high attrition rate, these findings may have important implications for clinicians as cannabis use may have serious consequences in psychiatric populations. Nevertheless, the mechanisms underlying this association remain unclear.

Dental injuries in Swiss soccer supporters: A comparative study of regular fans, ultras, and hooligans for public health strategies

OBJECTIVES

Violence among soccer supporters continues to pose a significant public health concern in many parts of the world. In Switzerland, hooliganism is largely uninvestigated. This study aimed to examine incidents of violence and associated dental injuries among different groups of soccer supporters, as well as assess the impact of intoxicants on their behavior, using survey data from regular fans, ultras, and hooligans in the Swiss Football League.

MATERIAL AND METHODS

A cross-sectional survey using a standardized questionnaire was conducted among distinct factions of soccer supporters in the Swiss Football League in 2022. A total of 165 participants self-identified as belonging to one of three subgroups: "regular fan," "ultra," or "hooligan." Data were gathered on physical altercations, dental injuries, possession of mouthguards, intoxicant use, and medical assistance. Descriptive statistics, logistic regression models, and significance tests were used for data analysis (α = .05).

RESULTS

Hooligans had a higher frequency of dental injuries resulting from fights than ultras and regular fans. Hooligans with 11-20 fights per soccer season had a 9.6 times higher probability of dental trauma than those with 0-5 fights (p = .048). Possession of a mouthguard was associated with a lower risk of dental injuries for hooligans but an increased risk for ultras. Additionally, hooligans were found to differ significantly from other groups in their consumption of amphetamines and cocaine (p < .001).

CONCLUSIONS

The study found a strong link between physical altercations and dental injuries among soccer supporters. To promote better prevention, there is a necessity for enhanced educational initiatives facilitated by dentists to amplify the dissemination of mouthguards. Furthermore, it is crucial to raise awareness regarding their proper fitting to minimize the occurrence of combat-related dental injuries. Health authorities and other stakeholders should take a comprehensive approach to addressing some of the root causes of violent behavior, which include alcohol abuse and illicit substance consumption.

Modeling state- and trait-level associations between aggression, somatic symptoms, substance use, and distress tolerance

The current study examined the state- and trait-level associations of psychological and physical aggression to somatic symptoms, and alcohol and drug use and tested the influence of distress tolerance on these associations, while controlling for stress, sex, and minority status. A naturalistic observation was used to collect data with a sample of 245 college students at three time points with 2 weeks apart. Random-intercept cross-lagged panel models were used to disaggregate within-person effects (autoregressive and cross-lagged effects) from the between-person (latent trait-level) associations. The findings revealed that there were autoregressive effects of psychological aggression between Time 1 (T1) and Time 2 (T2) and of physical aggression between T1 and T2. There was a bidirectional association between psychological aggression and somatic symptoms at T2 and Time 3 (T3), in which T2 psychological aggression predicted T3 somatic symptoms and verse vera. T1 drug use predicted T2 physical aggression, which in turn predicted T3 somatic symptoms, indicating physical aggression being a mediator between earlier drug use and later somatic symptoms. Distress tolerance was negatively associated with psychological aggression and somatic symptoms, respectively, and such an influence did not differ across time occasions. The findings indicated the importance of incorporating physical health in the prevention and intervention of psychological aggression. Clinicians may also consider including psychological aggression in the screening of somatic symptoms or physical health. Empirical-supported therapy components for enhancing distress tolerance may help mitigate psychological aggression and somatic symptoms.

Combined use of cocaine and alcohol: A violent cocktail? A systematic review

It is generally believed that the use of alcohol and cocaine alone and especially in combination elicits aggression and violent behaviour. Though there is overwhelming proof that heavy alcohol use is associated with violence, this is not the case for cocaine. Still, in the popular press and by spokesmen of the police, cocaine use is seen as a cause of violent incidents. In the current systematic review, available data from human studies on the relation between cocaine and violent behaviour is presented. In particular, we present scientific data on the acute induction of violence by cocaine alone, as well as, that by the combination of cocaine and alcohol known to be frequently used simultaneously. RESULTS: show that there is only weak scientific evidence for the acute induction of violent behaviour by cocaine, either when used alone or in combination with alcohol. Based on these data we were also able to refute misconceptions about the relation between cocaine and violence published in the popular press and governmental reports, because it appeared that there was hardly any empirical support for this widely shared opinion. Probably, contextual factors, including cocaine use disorder and personality disorder, may better explain the assumed association between cocaine and violence.

The role of aggression in substance use: The prison case

OBJECTIVES

Substance use and aggressive behaviour pattern is considered as a serious criminal behaviour threat. This analytical cross-sectional study was designed to determine the level of aggression of convicts with substance use and to determine the variables predicting the substance use characteristics of convicts.

METHODS

The study was carried out with 255 male convicts in 2 different closed penal execution institutions in Izmir province. In order to measure demographic variables, data were collected using the Information Form, Buss Perry Aggression Questionnaire and Addiction Profile Index.

RESULTS

When convicts were examined according to demographic variables, it was found that there was a significant difference between the groups in terms of variables such as age, marital status, domestic violence, history of psychological treatment and self-harm behaviour. The results showed that 85.5% of convicts had used cannabis more than three times in their lifetime. Also there was a significant difference between the total score obtained from the aggression scale and the number of substance types used.

CONCLUSIONS

Multidisciplinary approach in the field of addiction can go a long way in solving the problem and will play an important role in the protection of society, individuals and victims.

Endocannabinoid system and aggression across animal species

This narrative review article summarizes the current state of knowledge regarding the relationship between the endocannabinoid system (ECS) and aggression across multiple vertebrate species. Experimental evidence indicates that acute administration of phytocannabinoids, synthetic cannabinoids, and the pharmacological enhancement of endocannabinoid signaling decreases aggressive behavior in several animal models. However, research on the chronic effects of cannabinoids on animal aggression has yielded inconsistent findings, indicating a need for further investigation. Cannabinoid receptors, particularly cannabinoid receptor type 1, appear to be an important part of the endogenous mechanism involved in the dampening of aggressive behavior. Overall, this review underscores the importance of the ECS in regulating aggressive behavior and provides a foundation for future research in this area.

The Role of Corticotropin-Releasing Factor (CRF) and CRF-Related Peptides in the Social Behavior of Rodents

Since the corticotropin-releasing factor (CRF) was isolated from an ovine brain, a growing family of CRF-related peptides has been discovered. Today, the mammalian CRF system consists of four ligands (CRF, urocortin 1 (Ucn1), urocortin 2 (Ucn2), and urocortin 3 (Ucn3)); two receptors (CRF receptor type 1 (CRF1) and CRF receptor type 2 (CRF2)); and a CRF-binding protein (CRF-BP). Besides the regulation of the neuroendocrine, autonomic, and behavioral responses to stress, CRF and CRF-related peptides are also involved in different aspects of social behavior. In the present study, we review the experiments that investigated the role of CRF and the urocortins involved in the social behavior of rats, mice, and voles, with a special focus on sociability and preference for social novelty, as well as the ability for social recognition, discrimination, and memory. In general, these experiments demonstrate that CRF, Ucn1, Ucn2, and Ucn3 play important, but distinct roles in the social behavior of rodents, and that they are mediated by CRF1 and/or CRF2. In addition, we suggest the possible brain regions and pathways that express CRF and CRF-related peptides and that might be involved in social interactions. Furthermore, we also emphasize the differences between the species, strains, and sexes that make translation of these roles from rodents to humans difficult.

Neurobiology of Aggression-Review of Recent Findings and Relationship with Alcohol and Trauma

Aggression can be conceptualized as any behavior, physical or verbal, that involves attacking another person or animal with the intent of causing harm, pain or injury. Because of its high prevalence worldwide, aggression has remained a central clinical and public safety issue. Aggression can be caused by several risk factors, including biological and psychological, such as genetics and mental health disorders, and socioeconomic such as education, employment, financial status, and neighborhood. Research over the past few decades has also proposed a link between alcohol consumption and aggressive behaviors. Alcohol consumption can escalate aggressive behavior in humans, often leading to domestic violence or serious crimes. Converging lines of evidence have also shown that trauma and posttraumatic stress disorder (PTSD) could have a tremendous impact on behavior associated with both alcohol use problems and violence. However, although the link between trauma, alcohol, and aggression is well documented, the underlying neurobiological mechanisms and their impact on behavior have not been properly discussed. This article provides an overview of recent advances in understanding the translational neurobiological basis of aggression and its intricate links to alcoholism and trauma, focusing on behavior. It does so by shedding light from several perspectives, including in vivo imaging, genes, receptors, and neurotransmitters and their influence on human and animal behavior.

The Dopamine System in Mediating Alcohol Effects in Humans

Brain-imaging studies show that the development and maintenance of alcohol use disorder (AUD) is determined by a complex interaction of different neurotransmitter systems and multiple psychological factors. In this context, the dopaminergic reinforcement system appears to be of fundamental importance. We focus on the excitatory and depressant effects of acute versus chronic alcohol intake and its impact on dopaminergic neurotransmission. Furthermore, we describe alterations in dopaminergic neurotransmission as associated with symptoms of alcohol dependence. We specifically focus on neuroadaptations to chronic alcohol consumption and their effect on central processing of alcohol-associated and reward-related stimuli. Altered reward processing, complex conditioning processes, impaired reinforcement learning, and increased salience attribution to alcohol-associated stimuli enable alcohol cues to drive alcohol seeking and consumption. Finally, we will discuss how the neurobiological and neurochemical mechanisms of alcohol-associated alterations in reward processing and learning can interact with stress, cognition, and emotion processing.

Violence - suicide and suicidal ideation as sequelae of trauma in substance use disorder inpatients

Experience with psychological trauma is overrepresented among substance use disorder (SUD) patients. SUDs may also be a risk factor for violent behaviors, suicidal ideation and suicide. This study proposes a link between these phenomena. Based on data from the EuropASI clinical interview of 137 SUD inpatients we computed a composite variable of trauma experience from being abused. We report descriptive data and cross tabulated problems controlling violent behavior, suicidal ideation or suicide attempts variables with trauma experience. Hypothesizing an association between experienced trauma and the outcome variables. We also examined the correlation between three outcome variables in inpatients. Our data suggested high incidents of experienced psychological trauma in the sample (66.7%). Chi-square tests suggested a significant difference in controlling violent behavior, suicidal ideation and suicide attempts, dependent on trauma experience. Spearman Roh correlations suggested asscociations between suicdal ideation and suicide attempts, and suicdal ideation and problems controlling violent behavior, but not with suicide attempts. Our data suggests that past trauma is a risk factor for violent and suicidal behaviors in the SUD population. Based on our findings we propose that former trauma should be considered in risk assessments and help guide treatment interventions.

Does cannabis use predict aggressive or violent behavior in psychiatric populations? A systematic review

Background: Despite an increase in information evaluating the therapeutic and adverse effects of cannabinoids, many potentially important clinical correlates, including violence or aggression, have not been adequately investigated.Objectives: In this systematic review, we examine the published evidence for the relationship between cannabis and aggression or violence in individuals with psychiatric disorders.Methods: Following PRISMA guidelines, articles in English were searched on PubMed, Google Scholar, MEDLINE, and PsycINFO from database inception to January 2022. Data for aggression and violence in people with psychiatric diagnoses were identified during the searches.Results: Of 391 papers identified within the initial search, 15 studies met inclusion criteria. Cross-sectional associations between cannabis use and aggression or violence in samples with post-traumatic stress disorder (PTSD) were found. Moreover, a longitudinal association between cannabis use and violence and aggression was observed in psychotic-spectrum disorders. However, the presence of uncontrolled confounding factors in the majority of included studies precludes any causal conclusions.Conclusion: Although cannabis use is associated with aggression or violence in individuals with PTSD or psychotic-spectrum disorders, causal conclusions cannot be drawn due to methodological limitations observed in the current literature. Well-controlled, longitudinal studies are needed to ascertain whether cannabis plays a causal role on subsequent violence or aggression in mental health disorders.

The effect of alcohol consumption on workplace aggression: What's love (and job insecurity) got to do with it?

Purpose

The authors tested whether the effect of alcohol consumption during work hours on workplace aggression was influenced by the combined impact of individuals' job insecurity and love of the job.

Design/methodology/approach

The authors employed a time-lagged design whereby 325 working adults (166 men; 159 women) provided data at two time points. Respondents were asked to report their typical alcohol consumption volume in a workday, the extent to which they loved their job, and how insecure they felt about their job. Approximately one week later, respondents completed a workplace aggression measure.

Findings

A substantial positive relationship was observed between the volume of alcohol consumed during work hours and the likelihood of aggressive acts. Beyond this preliminary finding, the authors found evidence for a three-way interaction. It appears that the fear of losing a beloved job creates a condition under which the drinking-aggression relationship is particularly strong.

Practical implications

Besides formal rules deterring alcohol consumption during work hours, managers may look to implement measures that nurture a sense of job love and job security, which can be beneficial in preventing aggression resulting from drinking in the workplace.

Originality/value

By examining alcohol consumption during a typical workday, the study captures the contextual and proximal effects of drinking, which are often not observed in workplace-focused studies that operationalize alcohol consumption in general terms. The findings also suggest that if employees who drink during work hours are afraid of losing the job they love, a particularly stressful situation is created in which workplace aggression is more likely to happen.

Crime-Specific Recidivism in Criminal Justice Clients with Substance Use—A Cohort Study

Criminal recidivism is a major global concern. There is a well-known association between substance use disorders and offending. Yet, little is known about crime-specific recidivism. The aim of this study was to investigate the relationship between specific substance use and crime-specific recidivism. The study is based on 4207 Swedish prison clients with substance use assessed with Addiction Severity Index interviews between 2001 and 2006. Clients were followed for an average of 2.7 years. Risk factors for criminal recidivism were assessed with the Cox regression analysis. Sixty-eight percent of the clients returned to the criminal justice system. Apart from well-known risk factors such as male gender and young age, amphetamine, injection drug use, prior prosecution for violent and property crime, as well as homelessness and psychiatric problems, were risk factors for criminal recidivism. Sedatives and cannabis were, in this setting, negative risk factors for general recidivism. Age, heroin and injection drug use elevated the risks of recidivism to property and drug crime. Alcohol was associated with violent recidivism. When analysing different categories of crime separately, risk factors differed substantially. This further highlights the need for crime-specific research. Identifying crime-specific risk factors should be an important part of improving rehabilitation into society after imprisonment and hopefully decrease recidivism.

Prevalence and determinants of aggressive behavior among adults with problematic substance use in Northwest Ethiopia: a cross-sectional survey

BACKGROUND

The recent WHO data reported that a high treatment gap for behavioral illnesses (70%) in low- and- middle-income countries and the mortality rate of aggressive behavior reaches up to 32.1 per 100,000 populations in the region. However, the magnitude of aggressive behavior is not well stated in resource-limited settings. Therefore, the aim of this study was to assess the prevalence and determinant factors of aggressive behavior among adults with problematic substance use in northwest Ethiopia.

METHODS

A community-based cross-sectional study was employed from January to March 2019. A multi-stage cluster sampling method was used to screen a total of 4028 adults for problematic substance use by using the Cutdown, Annoyed, Guilty, and Eye-opener questionnaire (CAGE AID). Finally, 838 participants were positive for problematic substance use and interviewed for aggressive behavior using a modified overt aggression scale. Multiple logistic regression analysis was used to show the adjusted odds ratios (AOR) and p-value < 0.05 considered statistically significant. A multilevel binary logistic regressions model was employed for the hierarchical structure of two-level data for the individual and woreda/district levels.

RESULTS

The prevalence of aggressive behavior was found to be 37.9% (301/795, 95% CI: 34.5, 41.3). Stressful life events (AOR = 2.209, 95 CI; 1.423, 3.429), family history of mental illness (AOR = 4.038, 95 CI; 2.046, 7.971), comorbid physical illness (AOR = 2.01, 95 CI; 1.332, 3.032) and depressive symptoms (AOR = 2.342, 95 CI; 1.686, 3.253) were associated with aggressive behavior among individual with problem substance use.

CONCLUSION

Aggressive behavior was found to be high among problematic substance uses. An individual with problematic substance use is recommended to be screened by health extension workers for aggressive behavior at the community level.

Illicit drug use and male barroom aggression among members of the Australian construction industry: Associations with personality and masculinity factors

Introduction

Illicit drug use has been found to increase the risks of male barroom aggression (MBA). Personality traits such as dispositional aggressiveness have been associated with illicit substance use and aggressive behaviour, along with social normative masculinity factors. The present study assessed the relationships between illicit drug use, key personality (trait aggression, impulsivity, narcissism) and masculinity (conformity to masculine norms, male honour) variables with physical MBA perpetration and victimisation among male Australian construction workers.

Methods

A purposive, high‐risk sample of male construction workers aged 18–69 years (n = 476, M_age = 25.90 years, SD_age = 9.44) completed interviews at their place of work or training.

Results

Participants reported high rates of both physical MBA perpetration (21%; n = 100) and victimisation (31.1%; n = 148) as well as any illicit drug use (33.61%; n = 160). Logistic regressions revealed the use of amphetamine‐type stimulants (methamphetamine, ecstasy) was associated with violence perpetration, even after accounting for high‐intensity drinking (HID) which was the strongest predictor of MBA involvement. Trait variables (Trait Physical aggressiveness, narcissism) and the masculine norm CMNI Violence were also risk factors for MBA perpetration while CMNI Playboy was protective against MBA.

Discussion and Conclusions

The use of amphetamine‐type stimulants is a risk‐factor for MBA perpetration, as are key personality traits such as aggressiveness and narcissism. Most aspects of masculinity, including male honour, were either unrelated to or protective against involvement in physical violence in bars, clubs or pubs.

Receptor-Mediated AKT/PI3K Signalling and Behavioural Alterations in Zebrafish Larvae Reveal Association between Schizophrenia and Opioid Use Disorder

The link between substance abuse and the development of schizophrenia remains elusive. In this study, we assessed the molecular and behavioural alterations associated with schizophrenia, opioid addiction, and opioid withdrawal using zebrafish as a biological model. Larvae of 2 days post fertilization (dpf) were exposed to domperidone (DMP), a dopamine-D2 dopamine D2 receptor antagonist, and morphine for 3 days and 10 days, respectively. MK801, an N-methyl-D-aspartate (NMDA) receptor antagonist, served as a positive control to mimic schizophrenia-like behaviour. The withdrawal syndrome was assessed 5 days after the termination of morphine treatment. The expressions of schizophrenia susceptibility genes, i.e., pi3k, akt1, slc6a4, creb1 and adamts2, in brains were quantified, and the levels of whole-body cyclic adenosine monophosphate (cAMP), serotonin and cortisol were measured. The aggressiveness of larvae was observed using the mirror biting test. After the short-term treatment with DMP and morphine, all studied genes were not differentially expressed. As for the long-term exposure, akt1 was downregulated by DMP and morphine. Downregulation of pi3k and slc6a4 was observed in the morphine-treated larvae, whereas creb1 and adamts2 were upregulated by DMP. The levels of cAMP and cortisol were elevated after 3 days, whereas significant increases were observed in all of the biochemical tests after 10 days. Compared to controls, increased aggression was observed in the DMP-, but not morphine-, treated group. These two groups showed reduction in aggressiveness when drug exposure was prolonged. Both the short- and long-term morphine withdrawal groups showed downregulation in all genes examined except creb1, suggesting dysregulated reward circuitry function. These results suggest that biochemical and behavioural alterations in schizophrenia-like symptoms and opioid dependence could be controlled by common mechanisms.

Characteristics of depression, anxiety, impulsivity, and aggression among various types of drug users and factors for developing severe depression: a cross-sectional study

BACKGROUND

Mood disorder, impulsivity and aggression are common in drug users compared to healthy controls. However, no study has focused on the difference in various types of drug users. Therefore, the objective of this study was to explore the differences in depression, anxiety, impulsivity, and aggression among methamphetamine, heroin and polysubstance users and to further explore the risk factors for severe depression in the three groups.

METHODS

Drug users over 18 years old who met the DSM-V diagnostic criteria for substance -related disorders were included in the study. All participants completed a general questionnaire, the Zung Self-Rating Depression Scale (SDS), the Zung Self-Rating Anxiety Scale (SAS), Barratt impulsiveness Scale Version 11 (BIS-11), and the Buss-Perry Aggression Questionnaire (BPAQ). One-way ANOVAs or Chi-square tests were used to test the differences among the groups, correlation analysis was used to test the relationship between drug use and other parameters, and multiple logistic regression was conducted to assess the risk factors for severe depression.

RESULTS

A total of 1,486 participants were included, comprising 86.3% males with a mean age of 38.97 years. There was a significant difference in the percentage of severe depression and SDS scores among the three groups, but no significant difference was found in SAS, BIS-11 and BPAQ scores. Using methamphetamines, hostility and anxiety were risk factors for developing severe depression in all the participants and anxiety remained constant in the other three groups. Moreover, methamphetamine use was 2.16 and 3.35 times more likely to cause severe depression than heroin and polysubstance use, respectively. The initial age of substance use was negatively correlated with BPAQ, SAS, and SDS scores, whereas the drug use duration and addiction duration were positively correlated.

CONCLUSIONS

In this study, we found that the highest prevalence of severe depression was in participants using methamphetamines and that using methamphetamines, hostility, and anxiety were risk factors for developing severe depression. This result addressed an important gap in our knowledge of the different characteristics of depression, anxiety, impulsivity and aggression in various types of substance users and provides clinicians and policy-makers with directions for intervention and preventing relapse.

The contribution of psychopathic traits and substance use in the prediction of recidivism of sexual offenders

Substance use and dependence may play an essential role in the risk of reoffending by sex offenders. Research examining the influence of substance use and dependence on the criminal behaviour of psychopathic sex offenders is limited. Alcohol and drug use have been identified as factors which promote criminal behaviour and are suspected to contribute, at least partially, to the probability of reoffending. For instance, previous research showed that elevated scores on the Michigan Alcohol Screening Test (MAST) contribute to the predictability of the Hare Psychopathy Checklist - Revised (PCL-R) on recidivism. The current study retrospectively evaluated a database of incarcerated high-risk offenders registered in the Regional Treatment Center, Sex Offender Treatment Program (RTCSOTP); in order to assess the contribution of self-disclosed histories of alcohol and substance use and dependency have, in concert with measures of psychopathic characteristics, on the predictability of recidivism. Results of the retrospective data identified PCL-R and DAST (Drug Abuse Screening Test) scores as significant predictors of sexual and violent recidivism of male inmates undergoing treatment in RTCSOTP within 5 years of their release. MAST scores, however, did not significantly contribute to the predictability of sexual and violent recidivism in this population. We conclude, drug use should be considered as an important factor when addressing recidivism in sexual offenders who demonstrate psychopathic characteristics.

Prevalence and correlates of aggressive behavior in psychiatric inpatient populations

Aggressive behavior in patients with psychiatric disorders is attracting increasing research interest. One reason for this is that psychiatric patients are generally considered more likely to be aggressive, which raises a related question of whether diagnoses of psychiatric disorders predict the prevalence of aggressive behavior. Predicting aggression in psychiatric wards is crucial, because aggressive behavior not only endangers the safety of both patients and staff, but it also extends the hospitalization times. Predictions of aggressive behavior also need careful attention to ensure effective treatment planning. This literature review explores the relationship between aggressive behavior and psychiatric disorders and syndromes (dementia, psychoactive substance use, acute psychotic disorder, schizophrenia, bipolar affective disorder, major depressive disorder, obsessive-compulsive disorder, personality disorders and intellectual disability). The prevalence of aggressive behavior and its underlying risk factors, such as sex, age, comorbid psychiatric disorders, socioeconomic status, and history of aggressive behavior are discussed as these are the components that mostly contribute to the increased risk of aggressive behavior. Measurement tools commonly used to predict and detect aggressive behavior and to differentiate between different forms of aggressive behavior in both research and clinical practice are also reviewed. Successful aggression prevention programs can be developed based on the current findings of the correlates of aggressive behavior in psychiatric patients.

Use of alcohol and illicit drugs by trauma patients in Sao Paulo, Brazil

INTRODUCTION

Alcohol and illicit drugs impair cognitive and psychomotor skills and may thereby increase the risk of involvement in a road traffic crash and other types of injuries. However, the knowledge on the use of psychoactive substances among injured patients presenting to emergency departments in low and middle-income countries remains limited.

AIMS

To estimate the prevalence of alcohol and illicit drug use among patients with traumatic injuries admitted to an emergency department in Sao Paulo, Brazil.

METHODS

Blood samples from injured patients requiring hospitalization for more than 24 h due to road traffic crashes, falls, or violence, were collected from July 2018 to June 2019. The samples were analyzed for alcohol and illicit drugs.

RESULTS

A total of 376 patients were included in this study; the median age was 36 years and 80% of patients were male. The majority (56%) of injuries resulted from road traffic crashes, with approximately half of them being motorcyclists. Alcohol, drugs, or both were detected in 32% of samples. The proportion that tested positive was highest for males (35%), for the age group 18-39 years (41%), for singles (43%), and for patients injured at nighttime (44%). Patients injured due to violence had the highest prevalence of alcohol or drugs in their blood samples (44%). Alcohol was most prevalent (23%), followed by cocaine (12%) and cannabis (5%).

CONCLUSION

The use of alcohol and illicit drugs was common among injured patients in Sao Paulo; it was likely a contributing factor in a third of the injurious accidents. Alcohol was the most prevalent substance followed by cocaine and cannabis.

Dopamine promotes aggression in mice via ventral tegmental area to lateral septum projections

Septal-hypothalamic neuronal activity centrally mediates aggressive behavior and dopamine system hyperactivity is associated with elevated aggression. However, the causal role of dopamine in aggression and its target circuit mechanisms are largely unknown. To address this knowledge gap, we studied the modulatory role of the population- and projection-specific dopamine function in a murine model of aggressive behavior. We find that terminal activity of ventral tegmental area (VTA) dopaminergic neurons selectively projecting to the lateral septum (LS) is sufficient for promoting aggression and necessary for establishing baseline aggression. Within the LS, dopamine acts on D2-receptors to inhibit GABAergic neurons, and septal D2-signaling is necessary for VTA dopaminergic activity to promote aggression. Collectively, our data reveal a powerful modulatory influence of dopaminergic synaptic input on LS function and aggression, effectively linking the clinically pertinent hyper-dopaminergic model of aggression with the classic septal-hypothalamic aggression axis.

Predictors and moderators of marijuana and heavy alcohol use outcomes in adolescents treated for co-occurring substance use and psychiatric disorders in a randomized controlled trial

BACKGROUND

The current study identifies predictors and moderators of substance use outcomes for 111 adolescents with co-occurring substance use and psychiatric disorders who participated in a randomized controlled trial that compared the effectiveness of two home-based treatments: an integrated cognitive behavioral therapy (I-CBT) protocol, in which masters-level clinic staff received intensive training and ongoing supervision in the use of this protocol versus a treatment-as-usual (TAU) comparison condition in which therapists received a continuing education-style CBT workshop in the same protocol.

METHOD

The study conducted exploratory predictor and moderator analyses of marijuana and heavy alcohol use outcomes using candidate variables across four domains of psychological characteristics: adolescent substance use, adolescent psychiatric symptoms, parent, and family.

RESULTS

Regardless of treatment condition, low parental monitoring at baseline, as assessed by a videotaped interaction task, but not self-report, predicted greater percentage of marijuana use and heavy alcohol use days over the 6-month follow-up period. If parents entered treatment with low levels of parental monitoring, adolescents in the I-CBT condition reduced their percentage of heavy alcohol use days significantly more than adolescents in TAU over the 6-month follow-up period. Greater adolescent aggression and parental emotion dysregulation at baseline also predicted greater percentage of marijuana use days over the 6-month follow-up period for the sample as a whole. Adolescents in the I-CBT condition who reported low positive urgency at baseline reduced their percentage of heavy alcohol use days significantly more than adolescents in TAU care over the 6-month follow-up period.

CONCLUSION

The article discusses implications for clinical decision-making, improving treatment effectiveness, and tailoring interventions for adolescents with co-occurring substance use and psychiatric disorders.

Transcranial Direct Current Stimulation Targeting the Ventromedial Prefrontal Cortex Reduces Reactive Aggression and Modulates Electrophysiological Responses in a Forensic Population

BACKGROUND

Studies have shown that impairments in the ventromedial prefrontal cortex play a crucial role in violent behavior in forensic patients who also abuse cocaine and alcohol. Moreover, interventions that aimed to reduce violence risk in those patients are found not to be optimal. A promising intervention might be to modulate the ventromedial prefrontal cortex by high-definition (HD) transcranial direct current stimulation (tDCS). The current study aimed to examine HD-tDCS as an intervention to increase empathic abilities and reduce violent behavior in forensic substance dependent offenders. In addition, using electroencephalography, we examined the effects on the P3 and the late positive potential of the event-related potentials in reaction to situations that depict victims of aggression.

METHODS

Fifty male forensic patients with a substance dependence were tested in a double-blind, placebo-controlled randomized study. The patients received HD-tDCS 2 times a day for 20 minutes for 5 consecutive days. Before and after the intervention, the patients completed self-reports and performed the Point Subtraction Aggression Paradigm, and electroencephalography was recorded while patients performed an empathy task.

RESULTS

Results showed a decrease in aggressive responses on the Point Subtraction Aggression Paradigm and in self-reported reactive aggression in the active tDCS group. Additionally, we found a general increase in late positive potential amplitude after active tDCS. No effects on trait empathy and the P3 were found.

CONCLUSIONS

Current findings are the first to find positive effects of HD-tDCS in reducing aggression and modulating electrophysiological responses in forensic patients, showing the potential of using tDCS as an intervention to reduce aggression in forensic mental health care.

Characteristics of depressed suicide attempters with remitted substance use disorders

Substance use disorder (SUD) comorbidity in mood disorders increases suicide risk. Suicide attempters with active SUD appear to have distinct characteristics but little is known whether these characteristics persist during remission and if they are related to different aspects of suicidal behavior. In this study, suicide attempters with a DSM mood disorder and remitted SUD (AT+SUD) (N = 135) were compared to those without lifetime SUD (AT-SUD) (N = 219) in terms of demographic, clinical and suicidal behavioral characteristics. Factor analyses were conducted to generate subjective distress and impulsivity/aggression factors - previously identified by our group to predict suicide risk in mood disorders. Associations between these traits and SUD history and suicidal behavior characteristics were then tested. Compared with AT-SUD, AT+SUD were more likely to be male, less educated and to have a Cluster B personality disorder. AT+SUD individuals had greater impulsivity/aggression factor scores, but comparable subjective distress scores. AT+SUD made a greater number of suicide attempts, with higher lethality, despite comparable suicide intent and degree of planning with AT-SUD. Impulsivity/aggression was higher in multiple versus single attempters, but did not correlate with suicide attempt lethality. Among suicide attempters with mood disorders, a history of lifetime SUD was associated with more frequent and more lethal suicide attempts. Among other correlates of lifetime SUD in this sample, impulsive/aggressive traits may explain greater frequency of suicide attempts. The results underscore that persons with mood disorders and lifetime SUD are at particularly high risk of frequent and lethal suicide attempts where more intensive prevention efforts are warranted.

Addressing Key Gaps in Existing Longitudinal Research and Establishing a Pathway Forward for Firearm Violence Prevention Research

The main purpose of this article and this special section is to encourage greater attention to the key gaps that exist in our understanding of the epidemiology of adolescent firearm violence and to provide a pathway forward for future longitudinal research that will inform prevention efforts. This increased attention is especially salient given: (a) firearms are the leading cause of death for adolescents and emerging adults in the United States, with the majority of these deaths due to interpersonal violence; (b) significant health and social disparities with regards to the populations that are most affected by interpersonal firearm violence have been documented; and, (c) limitations in federal research funding during the past 30 years have created a deficit of knowledge about key risk and protective factors necessary to inform evidence-based prevention efforts. We discuss the implications of the articles in this special edition for existing and novel prevention programs. We also identify key considerations for future epidemiological research, including the need for a greater focus on collecting longitudinal data among nationally representative samples enriched with subgroups of at-risk youth, the need to examine the role of protective factors and mediating variables within existing and novel theoretical models of firearm risk behaviors, the need to examine key factors across all levels of the socio-ecological model, and the need to incorporate novel and innovative research designs, methods and analyses.

A meta-analytic review of the relationship between cyber aggression and substance use

BACKGROUND

Prior research has demonstrated that various substances of abuse play a contributing role to acts of physical and verbal aggression. It is less clear if and to what extent substance use is associated with an increased risk in perpetrating cyber aggression, an emerging form of aggressive behavior that occurs through digital communication.

METHODS

A comprehensive review of the literature resulted in 15 studies and 18 unique samples from which effect size estimates were calculated.

RESULTS

Analyses resulted in a moderate, significant mean observed correlation indicating that individuals who engaged in substance use were more likely than those who did not to perpetrate cyber aggression (r = 0.24, k = 18, 95% CI = 0.20, 0.28). Comparing data across types of substances revealed that alcohol use represents a stronger risk factor for cyber aggression than nicotine, cannabis, or other illicit drugs. Results also suggest a stronger relationship between substance use and cyber aggression among older than younger samples and in the context of intimate partner rather than peer aggression. Comparable estimates of substance-related cyber aggression emerged across types of cyber aggression and perpetrator gender.

CONCLUSIONS

Further research is required to increase confidence in estimates used in moderation analyses. As with traditional aggression, alcohol use appears to represent a risk factor for cyber aggression, though it is unclear if the disinhibitory properties of alcohol are the mechanism of action for substance-related cyber aggression.

Profiles of Depressive Symptoms and Anger in Men: Associations With Postpartum Family Functioning

Background: Evidence suggests that men commonly experience depression as feelings of anger; yet, research has not investigated what this means for the manifestation of depressive symptoms in the early years of fatherhood and for key indicators of family functioning. Methods: Using data from a longitudinal cohort study of men at the normative age for entering fatherhood (28-32 years), we conducted latent class analyses to identify patterns of depressive symptoms and 3 sub-types of state anger (feeling; verbal; physical). We then assessed whether class membership was associated with paternity status (n = 535). In a subsample of fathers of infants aged up to 18 months (n = 162), we prospectively assessed associations with paternal-infant bonding, co-parenting, perceived social support, paternal involvement in childcare and alcohol use up to 2 years later. Results: Five classes emerged that differentiated men by anger and depressive symptom severity and by the degree to which men endorsed the feeling of wanting to express anger physically. Compared to the reference class with minimal symptoms, fathers had a higher probability of being in either the mild or most severe symptom classes. Men in symptomatic classes were at higher risk of lower levels of social support, co-parenting problems, and paternal-infant bonds. Class membership was not associated with alcohol use or paternal involvement in childcare. Conclusions: Our results reveal patterns of co-existing symptoms of depression and anger in fathers of infants that will be relevant to men's own need for support, their family safety, partner mental health and child developmental outcomes.

Effects of acute alcohol consumption on emotion recognition in high and low trait aggressive drinkers

BACKGROUND

Research suggests that acute alcohol consumption impairs processing of emotional faces. As emotion processing plays a key role in effective social interaction, these impairments may be one mechanism by which alcohol changes social behaviour. This study investigated the effect of individual differences on this relationship by comparing emotion recognition performance after acute alcohol consumption in individuals with high and low trait aggression.

METHODS

Regular non-dependent drinkers, either high or low in trait aggression participated in a double-blind placebo-controlled experiment (N = 88, 50% high trait aggressive). Participants attended two sessions. In one they consumed an alcoholic drink (0.4 g/kg) and in the other they consumed a matched placebo. They then completed two computer-based tasks: one measured global and emotion-specific recognition performance across six primary emotions (anger, sadness, happiness, disgust, fear, surprise), the other measured processing bias of two ambiguously expressive faces (happy-angry/happy-sad).

RESULTS

There was evidence of poorer global emotion recognition after alcohol. In addition, there was evidence of poorer sensitivity to sadness and fear after alcohol. There was also evidence for a reduced bias towards happiness following alcohol and weak evidence for an increased bias towards sadness.

CONCLUSIONS

These findings suggest that alcohol impairs global emotion recognition. They also highlight a reduced ability to detect sadness and fearful facial expressions. As sadness and fear are cues of submission and distress (i.e. function to curtail aggression), failure to successfully detect these emotions when intoxicated may increase the likelihood of aggressive responding. This coupled with a reduced bias towards seeing happiness may collectively contribute to aggressive behaviour.

Structure and therapeutic uses of butyrylcholinesterase: Application in detoxification, Alzheimer's disease, and fat metabolism

Structural information of butyrylcholinesterase (BChE) and its variants associated with several diseases are discussed here. Pure human BChE has been proved safe and effective in treating organophosphorus (OPs) poisoning and has completed Phase 1 and 2 pharmacokinetic (PK) and safety studies. The introduction of specific mutations into native BChE to endow it a self-reactivating property has gained much progress in producing effective OPs hydrolases. The hydrolysis ability of native BChE on cocaine has been confirmed but was blocked to clinical application due to poor PK properties. Several BChE mutants with elevated cocaine hydrolysis activity were published, some of which have shown safety and efficiency in treating cocaine addiction of human. The increased level of BChE in progressed Alzheimer's disease patients made it a promising target to elevate acetylcholine level and attenuate cognitive status. A variety of selective BChE inhibitors with high inhibitory activity published in recent years are reviewed here. BChE could influence the weight and insulin secretion and resistance of BChE knockout (KO) mice through hydrolyzing ghrelin. The BChE-ghrelin pathway could also regulate aggressive behaviors of BChE-KO mice.

Social housing promotes recovery of wheel running depressed by inflammatory pain and morphine withdrawal in male rats

The increased use of opioids to treat pain has led to a dramatic increase in opioid abuse. Our previous data indicate that pain may facilitate the development of opioid abuse by increasing the magnitude and duration of opioid withdrawal. The present study tested the hypothesis that social housing would facilitate recovery of activity depressed by pain and opioid withdrawal. Male Sprague Dawley rats were housed either in pairs or alone and then moved to a cage with a running wheel for 6 h daily to assess pain- and opioid withdrawal-induced depression of wheel running. Rats were implanted with two morphine (75 mg each) or placebo pellets to induce opioid dependence and were simultaneously injected with Complete Freund's Adjuvant or saline into the right hind paw to induce persistent inflammatory pain. Hind paw inflammation depressed wheel running whether rats were implanted with a morphine or placebo pellet. Pair-housed rats showed greater recovery of wheel running than individually housed rats. Spontaneous morphine withdrawal precipitated by removal of the morphine pellets caused a reduction in wheel running that was greater in rats with hind paw inflammation compared to pain free rats. Social housing facilitated recovery from withdrawal in rats with hind paw inflammation, but slowed recovery in pain free rats. These data suggest that social housing facilitates recovery by reducing pain both before and during opioid withdrawal. Our findings are consistent with previous studies showing that social buffering reduces pain-evoked responses.

The CRF1 receptor mediates social behavior deficits induced by opiate withdrawal

Poor sociability and aggressive behavior are key clinical features of opioid use disorders. The corticotropin-releasing factor (CRF) system may mediate behavioral effects of substances of abuse but its implication in substance-induced social behavior deficits and outward-directed hostility remains largely unknown. CRF signaling is mediated by two receptor types, termed CRF₁ and CRF₂ . The present study aimed at understanding the role for the CRF₁ receptor in social and aggressive behavior induced by withdrawal from repeated opiate administration. Thus, wild-type (CRF₁ +/+), CRF₁ receptor heterozygous (CRF₁ +/-), and null mutant (CRF₁ -/-) female and male mice were treated with saline or escalating doses of morphine (20-100 mg/kg, i.p.) during six consecutive days and tested in the three-chamber task for sociability (i.e., preference for an unfamiliar same-sex conspecific vs. an object) 7 days after the last administration. Moreover, aggressive biting behavior toward the unfamiliar conspecific was assessed during the three-chamber test. Opiate withdrawal disrupted sociability in CRF₁ +/+ and CRF₁ +/-, but not in CRF₁ -/-, female mice, without affecting aggressive biting behavior in any genotype. In contrast, opiate withdrawal did not affect sociability but increased aggressive biting behavior in male mice, independently of CRF₁ receptor-deficiency. Nevertheless, in opiate-withdrawn CRF₁ +/+, but not CRF₁ +/- and CRF₁ -/-, male mice, sociability directly correlated with aggressive biting behavior, suggesting a role for the CRF₁ receptor in hostility-linked social approach. These findings demonstrate the implication of the CRF₁ receptor in social behavior deficits associated with repeated opiate administration and withdrawal, revealing a new potential target for the treatment of opioid use disorders.

Assessing the public health impact of cannabis legalization in Canada: core outcome indicators towards an 'index' for monitoring and evaluation

The legalization of non-medical cannabis use and supply is impending in Canada. This constitutes a major policy change with the declared objective of improving public health outcomes, which requires rigorous monitoring and evaluation. While numerous different aspects associated with legalization will be examined, a focused perspective is required for effective policy evaluation purposes. To these ends, we have identified a set of 10 core indicators associated with cannabis-related risk/harm outcomes-based on current best evidence-that are expected to measure the primary impacts of legalization on public health outcomes. We briefly review these indicators, and their respective data availability in Canada. As ideally an integrated outcome assessment of cannabis legalization's impact on public health will be available, we further propose options to merge the individual indicators into an integrated, weighted 'index', considering their expected relative impact for public health. One possible approach to undertake this is 'multi-criteria decision analysis' as a method to weight the relative indicator impact on public health; alternative approaches are proposed. The integrated 'public health index' for cannabis legalization will allow for scientifically comprehensive, while focused, monitoring and evaluation of the effects of legalization in Canada for the benefits of science and evidence-based policy alike.

Association between homicide injury severity and benzodiazepine influence

There are case reports of offenders inflicting excessive injuries on their victims when under the influence of benzodiazepines. However, the potential association between benzodiazepine influence on the offender and victim injury severity in a general homicide population has not been studied. We investigated associations between offender positive testing for benzodiazepines or z-drugs (zolpidem, zopiclone and zaleplon) and victim injury severity. Data were drawn from 95 Swedish homicide cases from 2007–2009 in which offenders had known toxicology. There were no significant differences in injury severity between cases in which the offender tested positive vs. negative for benzodiazepines/z-drugs. Thus, the findings do not support the hypothesis that there is an association between benzodiazepine influence on the offender and victim injury severity in a general homicide population.

Key points

Some previous studies have linked benzodiazepines to aggression, violence and excessive homicide injuries.

The present study analysed the association between homicide injury severity and benzodiazepine status of the offender.

Offenders who tested positive for benzodiazepines did not inflict more severe injuries on their victims.

These findings do not support the hypothesis that benzodiazepine influence generally causes offenders to inflict more severe injuries on homicide victims.

Sex-linked roles of the CRF1 and the CRF2 receptor in social behavior

Dysfunctional social behavior is a major clinical feature of mood, anxiety, autism spectrum, and substance-related disorders, and may dramatically contribute to the poor outcome of these diseases. Nevertheless, the mechanisms underlying social behavior deficits are still largely unknown. The corticotropin-releasing factor (CRF) system, a major coordinator of the stress response, has been hypothesized to modulate social behavior. CRF signaling is mediated by two receptor types, termed CRF₁ and CRF₂ . Using the three-chamber task for sociability (i.e., preference for an unfamiliar conspecific vs. an object), this study demonstrates that CRF₂ receptor null mutation (CRF₂ -/-) reduces sociability in female mice but increases it in male mice. Both female and male CRF₂ -/- mice display a preference for social odor cues over neutral cues, indicating that sex- and CRF₂ receptor-dependent sociability is not due to altered olfaction or impaired social cues discrimination. Moreover, treatment with the CRF₁ receptor-preferring antagonist, antalarmin, consistently induces sociability in non-social mice but disrupts it in social mice, independently of CRF₂ receptor deficiency. Sex, CRF₂ receptor deficiency, or antalarmin affect locomotor activity during the three-chamber test. However, throughout the study CRF₁ and CRF₂ receptor-linked sociability is independent of locomotor activity. The present findings highlight major functions for the CRF system in the regulation of social behavior. Moreover, they provide initial evidence of sex-linked roles for the CRF₁ and the CRF₂ receptor, emphasizing the importance of sex as a major biological variable to be taken into consideration in preclinical and clinical studies.

Persistent cannabis use as an independent risk factor for violent behaviors in patients with schizophrenia

Although recent studies have shown a moderately strong association between cannabis use and violence among people with severe mental disorders, the direction of this association has not been investigated prospectively in a population with schizophrenia. Therefore, this study aims to determine, using cross-lag models, whether a temporal relationship between cumulative cannabis use and violence exists in a population with schizophrenia. The authors reported findings covering an 18-month period from a randomized, double-blind clinical trial of antipsychotic medications for schizophrenia treatment. Among the 1460 patients enrolled in the trial, 965 were followed longitudinally. Although persistent cannabis use predicted subsequent violence, violence did not predict cannabis use. The relationship was therefore unidirectional and persisted when controlling for stimulants and alcohol use. Finally, a significant body of evidence suggests a link between persistent cannabis use and violence among people with mental illnesses. Studies to further investigate the mechanisms underlying this association should be conducted.

Long-lasting pseudo-social aggressive behavior in opiate-withdrawn mice

Poor sociability and aggressive behavior are major clinical features of opiate use disorders that may contribute to the establishment and maintenance of these harmful diseases. The present study investigated the long-term effects of chronic morphine administration and withdrawal upon social and aggressive behavior as well as the interrelationship between these two behaviors. Thus, social behavior was measured in C57BL/6J male mice 7, 21, 35 and 49 days after cessation of escalating morphine doses (20-100 mg/kg, i.p.) administered during 6 consecutive days, using the three-chamber task for sociability (i.e., preference for an unfamiliar conspecific vs. an object) and social novelty preference (i.e., preference for a novel vs. a familiar conspecific). Moreover, aggressive biting behavior towards an unfamiliar conspecific was assessed throughout the three-chamber tests. Opiate withdrawal increased both social approach and aggressive biting behavior. Moreover, in morphine-withdrawn, but not in control, mice social approach and aggressive behavior followed a similar time-course and positively correlated one with each other, suggesting that social interest was mainly driven by aggressiveness. Aggressive biting behavior was still elevated 49 days after the last morphine administration, revealing that opiate withdrawal is followed by long-lasting aggressiveness. Throughout, opiate withdrawal did not affect social novelty preference, ruling out a role for olfactory or social discrimination dysfunction in the elevated social approach and aggressive behavior. The present findings of very long-lasting aggressive behavior and aggression-driven social approach in opiate-withdrawn mice might help understanding the behavioral and brain underpinnings of poor sociability and aggressiveness commonly observed in opiate use disorders patients.

Daily patterns of substance use and violence among a high-risk urban emerging adult sample: Results from the Flint Youth Injury Study

OBJECTIVE

Interpersonal violence is a significant public health problem, with substance use a key risk factor. Intensive longitudinal methods (ILMs) provide data on daily patterns/relationships between substance use and violence, informing prevention. Prior daily research has not focused on these relationships among urban minority samples.

METHODS

Within an RCT comparing ILM assessment/schedule methods, 162-participants completed daily IVR (n = 81) or SMS (n = 81) assessments measuring 19 substance use and violence (partner/non-partner) behaviors daily for 90-days. GLMMs characterized between- and within-person predictors of daily violence.

RESULTS

Participants [48.7%-female; age = 24.4; 62.3%-African-American; 66.7%-public assistance] completed an average of 46.5 daily reports [SD = 26.7]. Across 90-days, alcohol was characterized by episodic weekend use (average = 10 days-of-use, 34.4% drinking-days involved binge-drinking), while marijuana use was continuous (average = 27 days-of-use; 1.7 times/day), with no weekend differences. Among 118-violent conflicts, 52.5% occurred on weekends; 57.6% were with non-partners/peers; 61.0% involved perpetration/57.6% victimization; and 52.5% involved severe violence. For violence conflicts, 27.1% were preceded by alcohol/22.9% preceded by drug use. Between-person predictors of daily violence included retaliatory attitudes (AOR = 3.2) and anxiety (AOR = 1.1). Within-person predictors included weekends (AOR = 1.6), binge drinking (AOR = 1.9), non-medical prescription opioid use (AOR = 3.5) and illicit drug use (AOR = 8.1).

CONCLUSION

Among a high-risk urban minority sample, we found that higher baseline retaliatory attitudes and anxiety, as well as same-day binge drinking, non-medical prescription opioid use, and illicit drug use were associated with daily violence, likely reflecting both pharmacological and socio-contextual factors. Addressing substance use and retaliatory violence with tailored prevention efforts may aid in decreasing negative interpersonal violence outcomes.

Drug Use Disorders and Violence: Associations With Individual Drug Categories

We conducted a systematic review that examined the link between individual drug categories and violent outcomes. We searched for primary case-control and cohort investigations that reported risk of violence against others among individuals diagnosed with drug use disorders using validated clinical criteria, following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We identified 18 studies published during 1990–2019, reporting data from 591,411 individuals with drug use disorders. We reported odds ratios of the violence risk in different categories of drug use disorders compared with those without. We found odds ratios ranging from 0.8 to 25.0 for most individual drug categories, with generally higher odds ratios among individuals with polydrug use disorders. In addition, we explored sources of between-study heterogeneity by subgroup and meta-regression analyses. Cohort investigations reported a lower risk of violence than case-control reports (odds ratio =  2.7 (95% confidence interval (CI): 2.1, 3.5) vs. 6.6 (95% CI: 5.1, 8.6)), and associations were stronger when the outcome was any violence rather than intimate partner violence (odds ratio = 5.7 (95% CI: 3.8, 8.6) vs. 1.7 (95% CI: 1.4, 2.1)), which was consistent with results from the meta-regression. Overall, these findings highlight the potential impact of preventing and treating drug use disorders on reducing violence risk and associated morbidities.

Aggressive and Disruptive Behavior Among Psychiatric Patients With Major Depressive Disorder, Schizophrenia, or Alcohol Dependency and the Effect of Depression and Self-Esteem on Aggression

Aggressive and disruptive behavior in inpatient settings poses a serious challenge for clinical staff and fellow patients. Hence, the aim of this study was to identify different aspects of aggressive and disruptive behavior in the context of an aberrant self-esteem or clinically manifested depression as potentially influencing factors. We collected self-reported data from 282 psychiatric patients [ICD-10 diagnoses for alcohol dependency, schizophrenia or major depressive disorder (MDD)] and compared it to healthy norm groups. As expected, all three patient groups scored higher in the aggression questionnaires than the norm group. Specifically, patients with MDD exhibited significantly higher externally directed aggression, reactive aggression, and irritability compared to controls. Patients with schizophrenia displayed higher irritability, while all three groups showed distinctly higher self-aggressiveness than healthy persons. We found a lower inhibition of aggression in alcohol dependent subjects compared to both the patient groups and the norm sample. Yet, the higher the self-esteem among alcohol dependent and MDD patients, the lower were their aggression scores; similarly, a lower self-esteem among patients diagnosed with schizophrenia resulted in heighten self-aggressiveness. Thus, our data suggests that therapeutic interventions for strengthening self-esteem in patients with a diagnosis of MDD, alcohol dependency or schizophrenia could reduce certain aspects of aggressive behavior. Therefore, it seems conceivable that strengthening self-esteem in psychiatric patients could contribute to the prevention of violence in clinical practice.

Rates and correlates of risky firearm behaviors among adolescents and young adults treated in an urban emergency department

Firearm violence is a leading cause of death for urban adolescents and young adults (A/YAs). Little is known about patterns of risky firearm behaviors (RFBs) that may increase firearm-related fatality and non-fatal injury risk. To inform prevention efforts, we examined the rates and correlates of RFBs, including firearm carriage in risky situations (e.g., while drunk/high), discharge in risky situations (e.g., fleeing police), and firearm aggression (e.g., firearm threats/use against a partner/non-partner), among a sample of A/YAs (age-16-29) seeking medical or injury related care (7/2017-6/2018) at a Level-1 urban Emergency Department (ED). In total, 1312 A/YAs completed the survey (mean-age 23.2; 29.6%-male; 50.5%-Black; 56.3%-public assistance), with 102 (7.8%) engaging in RFBs. Among those engaging in RFBs, 42% reported firearm ownership, 68.6% firearm carriage in high-risk situations, 39.2% firearm discharge in risky situations, and 41.2% reported partner/non-partner firearm aggression. Regression identified RFBs correlates, including older age (AOR = 1.09), male sex (AOR = 1.63), Black race/ethnicity (AOR = 2.01), substance misuse (AOR = 2.75), attitudes favoring firearm use/retaliation (AOR = 1.38), peer firearm ownership/carriage (AOR = 3.26), higher levels of community violence exposure (AOR = 1.05), and active parole/probation (AOR 2.38). Higher coping skills were protective for RFBs (AOR = 0.83). Overall, we found that A/YAs seeking urban ED treatment reported elevated RFB rates, emphasizing the need for novel prevention initiatives, especially those incorporating tailored content addressing substance use, retaliatory violence, and peer delinquency/norms, while enhancing self-efficacy for avoiding RFBs and providing access to external resources within a resiliency-based framework. Such prevention approaches may be a critical step towards addressing the public health problem of firearm violence. Primary Funding Sources: NIH/NIDA K23DA039341; NIH/NCATS UL1TR000433.

RBFOX1, encoding a splicing regulator, is a candidate gene for aggressive behavior

The RBFOX1 gene (or A2BP1) encodes a splicing factor important for neuronal development that has been related to autism spectrum disorder and other neurodevelopmental phenotypes. Evidence from complementary sources suggests that this gene contributes to aggressive behavior. Suggestive associations with RBFOX1 have been identified in genome-wide association studies (GWAS) of anger, conduct disorder, and aggressive behavior. Nominal association signals in RBFOX1 were also found in an epigenome-wide association study (EWAS) of aggressive behavior. Also, variants in this gene affect temporal lobe volume, a brain area that is altered in several aggression-related phenotypes. In animals, this gene has been shown to modulate aggressive behavior in Drosophila. RBFOX1 has also been associated with canine aggression and is upregulated in mice that show increased aggression after frustration of an expected reward. Associated common genetic variants as well as rare duplications and deletions affecting RBFOX1 have been identified in several psychiatric and neurodevelopmental disorders that are often comorbid with aggressive behaviors. In this paper, we comprehensively review the cumulative evidence linking RBFOX1 to aggression behavior and provide new results implicating RBFOX1 in this phenotype. Most of these studies (genetic and epigenetic analyses in humans, neuroimaging genetics, gene expression and animal models) are hypothesis-free, which strengthens the validity of the findings, although all the evidence is nominal and should therefore be taken with caution. Further studies are required to clarify in detail the role of this gene in this complex phenotype.