Lower catecholamine activity is associated with greater levels of anger in adults

Setting the tone for the day: Cortisol awakening response proactively modulates fronto-limbic circuitry for emotion processing

The cortisol awakening response (CAR) has been linked to a variety of emotion-related psychiatric conditions and is proposed to prepare the brain for upcoming stress and challenges. Yet, the underlying neurobiological mechanisms of such proactive effects on emotional processing remain elusive. In the current double-blinded, pharmacologically-manipulated study, 36 male adults (DXM group) received cortisol-repressive dexamethasone on the previous night, then performed the Emotional Face Matching Task (EFMT) during fMRI scanning the next afternoon. Relative to the placebo group (31 male adults), the DXM group exhibited lower accuracy in the emotion matching condition, but not in the sensorimotor control condition. Psychophysiological interaction (PPI) analyses revealed significant task-by-group interaction involving the right and left amygdala, but not the medial orbitofrontal cortex (MOFC) or hippocampus. Specifically, the DXM group exhibited stronger functional connectivity between the right amygdala and left dorsolateral prefrontal cortex (lDLPFC) during emotion condition but reduced connectivity in the same network during control condition, as compared to the placebo group. Meanwhile, the DXM group exhibited weaker left amygdala-right posterior middle temporal gyrus (rMTG) connectivity than the placebo group during control condition, but there was no group effect in the connectivity during emotion condition. These results indicate that the CAR proactively modulates fronto-limbic functional organization for emotion processing in male adults. Our findings support a causal link between CAR and its proactive effects on emotional processing, and suggest a model of CAR-mediated brain preparedness where CAR sets a tonic tone for the upcoming day to actively regulate neuroendocrinological responses to emotionally charged stimuli on a moment-to-moment basis.

Theories of Arousal Predict a Link Between Heart Rate Variability and Reactive Aggression: Meta-Analytic Results Disagree

Polyvagal theory posits that habitually aggressive individuals might have an impaired capacity to calm after arousal, which has led to the investigation of Arousal-based biological indicators - "biomarkers" - of aggression, to identify individuals at high risk. The most popular approach in research examining (specifically reactive) aggression is the use of wearable technologies that can non-invasively measure heart rate variability (HRV), a cardiovascular phenomenon impacted by activation of the parasympathetic ("rest and digest") nervous system. But there is a problem: no one has systematically analyzed the results of these studies to determine if HRV is an effective predictor of reactive aggression. We surveyed an initial 705 articles, producing 48 effect estimates amenable to meta-analysis. Counter to predictions derived from polyvagal theory, the results reveal no correlation between HRV and reactive aggression. We discuss the implications of this novel finding for theory and practice, considering both the complexity of identifying effective biomarkers and the practical limitations driving methodological decisions in aggression research. We conclude that there is no empirical evidence supporting HRV as a valid biomarker of aggression.

The Implications of Stress Among Correctional Officers: A Summary of the Risks and Promising Intervention Strategies

This paper provides a detailed summary and discussion of the concept of stress and how it relates to the health, wellbeing, and performance of corrections officers. In line with these objectives, we focus on three areas: (1) providing a more detailed definition of the concept of stress; (2) a discussion of the ways that increased exposure to stress may impact corrections officers' physical and mental health; and (3) a summary of prevention and intervention strategies that are relevant for corrections officers and have shown promise in dampening the consequences of increased stress exposure. More in-depth knowledge of the concept of stress and the underlying processes that link stress to negative outcomes will provide policy makers and corrections departments with an understanding of the characteristics of prevention and intervention strategies that are expected to be most effective in limiting the consequences of stress.

The centrality of cognition and coping styles in driving aggressive responses

OBJECTIVE

Despite the presence of theoretical frameworks explaining aggression, they still require refinement in the form of a specification of mechanisms that facilitate such behaviour.

METHOD

Study 1 recruited participants (N = 31) from the general population (N = 20) and from a forensic hospital (N = 11). It was expected that aggression supportive cognitions and stress would be positively associated with aggressive behaviour. An experimental paradigm was used to induce stress and participants were subsequently given the opportunity to aggress. Study 2 was based on self-report questionnaires in community sample (N = 462). It was expected that aggressive behaviour and traits would be associated with experienced stress, hostile attributions, coping styles, and attitudes to violence. Specifically, that criminal attitudes to violence will mediate the effect of hostile attribution on aggression, while coping styles will mediate the effect of perceived stress.

RESULTS

An Implicit Theory "I am the law" was found to be associated with aggression. Furthermore, elevated skin conductance, but not changes in the heart rate, during the stress task was positively associated with aggression, and only among patients. Structural Equation Model confirmed the mediating role of criminal attitudes to violence and of maladaptive coping style for aggressive behaviour.

CONCLUSION

Aggression-supportive cognitions and maladaptive coping style are specific mechanisms through which external demands or subjective perception of a situation can result in aggressive behaviour.

Effects of the Anger Management Program for Nurses

PURPOSE

The purpose of this study was to examine the effects of an anger management program on anger, job stress, psychological well-being, and heart rate variability in clinical nurses.

METHODS

A quasi-experimental study was conducted using a nonequivalent control group, pre-test-post-test design with repeated measures. The participants included 43 nurses assigned to the experimental and control groups. Anger, job stress, psychological well-being, and heart rate variability were evaluated before the intervention, immediately after the completion of the intervention, and four weeks after the end of the intervention. Chi-square test, t-test, Fisher's exact test, and GEE (Generalized Estimating Equations) were used to analyze the data.

RESULT

There were significant differences in the level of anger, state anger, job stress, and psychological well-being between the two groups. The rate of change in the total power (TP) and the high-frequency band (HF) of the experimental group increased immediately after the intervention completion but that of the control group decreased at the same time.

CONCLUSION

The above results demonstrate that an anger management program for nurses effectively attenuated anger and job stress, improved psychological well-being, and regulated heart rate variability.

A time to fight: Circadian control of aggression and associated autonomic support

The central circadian clock, located in the suprachiasmatic nucleus of the mammalian hypothalamus (SCN), regulates daily behavioral rhythms including the temporal propensity for aggressive behavior. Such aggression propensity rhythms are regulated by a functional circuit from the SCN to neurons that drive attack behavior in the ventromedial hypothalamus (VMH), via a relay in the subparaventricular zone (SPZ). In addition to this pathway, the SCN also regulates sleep-wake and locomotor activity rhythms, via the SPZ, in a circuit to the dorsomedial hypothalamus (DMH), a structure that is also known to play a key role in autonomic function and the sympathetic "fight-or-flight" response (which prepares the body for action in stressful situations such as an agonistic encounter). While the autonomic nervous system is known to be under pronounced circadian control, it is less apparent how such autonomic rhythms and their underlying circuitry may support the temporal propensity for aggressive behavior. Additionally, it is unclear how circadian and autonomic dysfunction may contribute to aberrant social and emotional behavior, such as agitation and aggression. Here we review the literature concerning interactions between the circadian and autonomic systems and aggression, and we discuss the implications of these relationships for human neural and behavioral pathologies.

Cigarette smoking duration mediates the association between future thinking and norepinephrine level

Fixating on the present moment rather than considering future consequences of behavior is considered to be a hallmark of drug addiction. As an example, cigarette smokers devalue delayed consequences to a greater extent than nonsmokers, and former smokers devalue delayed consequences more than nonsmokers, but less than current smokers. Further, cigarette smokers have higher norepinephrine levels than nonsmokers, which is indicative of poor future health outcomes. It is unclear how duration of cigarette smoking may impact these associations. The current secondary analysis of publicly available data investigated whether extent of future thinking is associated with smoking duration, as well as norepinephrine level, in a large national US sample (N = 985) of current, former, and never smokers. Individuals scoring lower on future thinking tended to smoke for longer durations and had higher norepinephrine levels relative to individuals scoring higher on future thinking. In addition, duration of cigarette abstinence interacted significantly with future thinking and smoking duration for former smokers. Specifically, the mediation relationship between future thinking, smoking duration, and norepinephrine level for former smokers was strongest at shorter durations of cigarette abstinence and decreased as a function of increasing duration of cigarette abstinence. Overall, results from this study suggest the potential importance of implementing smoking cessation treatments as early as possible for smokers and support future thinking as a potential therapeutic target for smoking cessation treatment.