Diurnal Cortisol Variation According to High-Risk Occupational Specialty Within Police: Comparisons Between Frontline, Tactical Officers, and the General Population

Effervescent-assisted Liquid-phase Microextraction Employing Switchable Hydrophilicity Solvent for the Determination of Cortisol and Testosterone in Oral Fluid by High-Performance Liquid Chromatography-Diode Array Detection

Cortisol and testosterone are important biomarkers for diagnosing complex disorders, including polycystic ovary syndrome and Cushing's syndrome, where symptomatology usually overlaps with other prevalent disorders. This work proposes, for the first time, an analytical method based on a switchable hydrophilicity solvent as an extraction phase for the determination of cortisol and testosterone in oral fluid (OF) by high-performance liquid chromatography with diode-array detection. The optimized extraction conditions consisted of 1000 µL of OF, 100 µL of decanoic acid solution (65 mg/mL), 170 µL of Na2CO3, 900 µL of H2SO4 and 150 µL of acetonitrile for dilution. The method was validated, and coefficients of determination higher than 0.9926, the limit of detection of 4.55 ng/mL and the limit of quantification of 15.00 ng/mL were obtained. Intra-day precision varied from 5.6% to 11.9%, inter-day precision ranged from 6.1% to 13.5%, and relative recoveries ranged from 98.9% to 104.6% for cortisol, and 89.1% to 103.9% for testosterone. This methodology was successfully applied to five OF samples from volunteers. Moreover, the greenness of this methodology was evaluated based on the sample preparation metric of sustainability achieving a global score of 7.37 which can be considered sustainable.

The International Performance, Resilience and Efficiency Program Protocol for the Application of HRV Biofeedback in Applied Law Enforcement Settings

Law enforcement officers are routinely exposed to high-threat encounters that elicit physiological stress responses that impact health, performance, and safety. Therefore, self-regulation using evidence-based approaches is a priority in police research and practice. This paper describes a five-module heart rate variability biofeedback (HRVB) protocol that is part of a larger resilience program (the International Performance Resilience and Efficiency Program - iPREP) established in 2014. Supported by 10 years of user-informed research and development, our methods are tailored to address occupational stressors and the practical realities of training and resource availability in operational settings. Building on existing clinical methods that comprise five to six weekly sessions and up to 40-min of daily practice, our iPREP HRVB protocol is typically delivered in a condensed format across 2-3 days and is seamlessly integrated with reality-based training scenarios commonly employed in policing. By combining best practices in clinical HRVB with police-specific pedagogical frameworks, officers receive accelerated and job-relevant training to adaptively modulate autonomic responses to acute and chronic stress. Efficacy of the iPREP HRVB protocol is supported by several research studies of various methodological designs (i.e., randomized control trial, longitudinal cohort) that demonstrate immediate and sustained improvements in police performance and physiological health outcomes. We conclude with a critical appraisal of the available empirical evidence contrasting common and emerging breathing techniques proposed for use in operational policing contexts. The critical appraisal guide is intended to serve as a resource for law enforcement agencies, governing bodies, and operators when choosing appropriate and effective self-regulation training approaches.

Physiological Responses to Organizational Stressors Among Police Managers

Police officers demonstrate increased risk of physical and mental health conditions due to repeated and prolonged exposure to stressful occupational conditions. Occupational stress is broken into two types: operational stress, related to the content of field duties (e.g., physical demands); and organizational stress, related to cultural and structural contexts (e.g., interpersonal relationships). Applied police research focuses on physiological activation in operational tasks as a mechanism explaining health risk and non-optimal performance outcomes. However, recent survey-based studies indicate numerous organizational stressors associated with self-reported mental health symptoms. The question of whether organizational stressors elicit significant physiological activity remains unknown. The current proof-of-concept field study tests the hypothesis that police managers will display significant physiological reactivity before, during, and after engaging in reality-based scenarios representative of stressful police management tasks developed from evidence-based pedagogical approaches. A sample of 25 training police managers (7 female, M = 16 +/- 5.3 years of experience) completed 5 reality-based scenarios, including resolving a heated conflict between colleagues, delivering negative feedback to a subordinate, and critical incident command. Significant increases in heart rate relative to rest were observed during all tasks, and in anticipation of several tasks. Greater increases in reactive heart rate were associated with longer recovery times. Sex differences and relationships between objective biological and subjective psychological measures of stress are discussed. The current findings demonstrate significant physiological responses to organizational stressors similar to levels observed during operational tasks, despite the absence of physical or aerobic exertion. Implications for police health and training are discussed.

Hair Cortisone Predicts Lower Stress-induced Salivary Cortisol Response: Resting-state Functional Connectivity Between Salience and Limbic Networks

Previous studies revealed that high long-term hypothalamic-pituitaryadrenal (HPA) axis activity measured by the hair cortisol concentrations predicts lower acute stress cortisol response and reported the influences of hair cortisol on brain activity during acute stress exposure. However, considering that long-term HPA axis activity has a close relationship with the brain's resting-state functional connectivity (RSFC), the current study aimed to explore the role of RSFC between limbic and salience network in this relationship. Seventy-seven healthy participants underwent resting-state imaging scans before performing the acute ScanSTRESS task. Saliva samples were collected to assess the levels of acute stress salivary cortisol. Hair samples were also collected, and the corticosteroid concentration extracted from these samples were used as a biomarker of long-term HPA axis activity. High hair cortisone (HairE) levels predicted lower acute stress cortisol response. Moreover, high HairE levels were significantly correlated with enhanced RSFC between limbic and salience networks, while RSFC was negatively associated with acute stress cortisol response. Importantly, the RSFC between left insula and left parahippocampus mediated the association between HairE and acute cortisol stress response. Taken together, this study uncovers the important role of RSFC between salience and limbic networks in the long-term relationship between HairE and acute cortisol response and contributes to a deeper understanding of the individual differences in acute stress response.

Associations between police lethal force errors, measures of diurnal and reactive cortisol, and mental health

Errors in lethal force by police are met with significant demand for explanations as to why they occur, stimulating a growing body of multidisciplinary research. Acutely stressful occupational conditions result in decrements to police performance, including lethal force decision-making. Further, although it is known that repeated and prolonged exposure to potentially traumatic work-related encounters is linked to higher rates of mental health symptoms, it is unclear if psychological symptoms are related to police performance, and lethal force errors specifically. The present study tested the relationships between biological stress and psychological symptoms on lethal force errors among a combined sample of non-clinical, active-duty frontline (n = 57) and tactical (n = 44) police officers. Specifically, biological measures included: diurnal (cortisol awakening response - CAR), and reactive cortisol (prior to and in response to realistic critical incident (CI) simulations). Psychological self-reported symptoms included: pre-CI stress, depression, anxiety, PTSD, and occupational stress. Tactical officers displayed higher CAR compared to frontline officers, consistent with prior research. When including outliers, CAR significantly predicted lethal force decision-making errors; however, the effect does not remain once removing the influence of outlier CAR observations. The current findings suggest that biological measures of reactive cortisol may be too nonspecific to predict lethal force errors during acutely stressful police operations and measures of diurnal cortisol are heavily influenced by outlier values. Non-clinical levels of psychological symptoms (as measured in this study) do not appear to interfere with lethal force decision-making. It remains to be tested if clinically diagnosed disorders would interfere with police performance. Implications for future applied health research are discussed.

Testing the Efficacy of a 1-Day Police Decision-Making and Autonomic Modulation Intervention: A Quasi-Random Pragmatic Controlled Trial

Contemporary discourse has identified several urgent priorities concerning police training and education, including: (a) empirically testing and validating the effectiveness of current programming in reducing lethal force decision-making errors; (b) integrating evidence-based content and pedagogical approaches into police curriculum; and (c) understanding the breadth and length of programming necessary to ensure learning and transfer of skills to operational field settings. Widespread calls to identify effective and actionable training programs have been met with numerous research studies, systematic reviews, and policy recommendations that reveal the need to train officers' internal physiological awareness, which is foundational in shaping cognitive decision-making, emotion regulation, and behavior under stressful conditions. Several investigations have shown improvements to both lethal force errors and physiological recovery following a multi-day autonomic modulation (AM) intervention. Immediate and sustained training gains are observed following repeated practice with clinically validated protocols integrated into training scenarios. Despite evidence-based support for AM in addressing the aforementioned priorities, police organizations are faced with limited time and funding for training and education. The goal of the current quasi-random pragmatic controlled trial was to evaluate the effectiveness of a modified 1-day version of an established AM intervention. A sample of active-duty police officers were quasi-randomly assigned to an AM intervention (n = 82) or waitlist control group (n = 105). Lethal force errors and objective measures of autonomic arousal and recovery were measured during reality-based scenarios pre- and post-training and at 12-month follow-up. In contrast to previous investigations of longer AM intervention protocols, no significant training-related improvements to behavioral or physiological outcomes were found immediately post-intervention or at follow-up. The current results suggest that single-day training is insufficient to learn the physiological awareness and regulation skills necessary to perform effectively during lethal force encounters, as demonstrated by a lack of immediate or sustained training effects. Practical considerations, such as resource allocation, that may undermine the effectiveness of implementing evidence-based police training are discussed.

The Role of Plant-Based Protein Functional Food in Preventing Acute Respiratory Disease: A Case Study

The Kaliningrad region is known for its specific climate, which can negatively affect the adaptive potential of the body. This manifests in an increased incidence of respiratory diseases and skin conditions. To prevent high morbidity, a plant protein product was included in the diet of first-year university students. This study aimed to assess the effectiveness of this food intervention in preventing the most common diseases among Kaliningrad students. Two groups of university students took part in the food trial. In the control group, catabolic processes prevailed in nutrient metabolism. Disadaptation manifested itself in the metabolism of proteins, vitamins, minerals, hematopoiesis and humoral immunity. Inflammation was indicated by α1- and α2-globulins, a weak immune response, and IgM and IgG. High oxidative stress and low antioxidative ability of blood serum were observed. The plant-based protein product (FP) helped preserve testosterone level and prevent an increase in catabolic reactions. Moreover, it had a positive effect on both red blood cell hematopoiesis (a smaller increase in the average volume of erythrocytes, the same average concentration and content of hemoglobin, an increased relative red cell distribution width (RDW) and white blood cell hematopoiesis (a beneficial effect for the immune system: lymphocytes, the relative content of neutrophils, monocytes, basophils and eosinophils). The stimulation of humoral immunity was evidenced by beta- and gamma-globulins, an active immune response, the level of IgM and IgG, antioxidant protection, reduction of peroxides and an increase in antioxidant activity of blood serum. The 34-week observation showed a 1.7-fold decrease in the incidence of respiratory illnesses and a 5.7-fold decrease in skin and subcutaneous tissue diseases. Acute respiratory infections were reduced 1.8-fold. There were no cases of community-acquired pneumonia in the treatment group, compared with 55.1‰ in the control group. The incidence of respiratory diseases was 3.3-10.6 times lower in the treatment group than in the control group in weeks 6-19. The findings testify to the prophylactic effect of functional food during social adaptation and acclimatization of students.

The impact of the COVID-19 pandemic on European police officers: Stress, demands, and coping resources

PURPOSE

Facing the COVID-19 pandemic, police officers are confronted with various novel challenges, which might place additional strain on officers. This mixed-method study investigated officers' strain over a three-month-period after the lockdown.

METHODS

In an online survey, 2567 police officers (77% male) from Austria, Germany, Switzerland, the Netherlands, and Spain participated at three measurement points per country in spring, 2020. Three-level growth curve models assessed changes in strain and its relation to stressor appraisal, emotion regulation, and preparedness through training. To add context to the findings, free response answers about officers' main tasks, stressors, and crisis measures were coded inductively.

RESULTS

On average, officers seemed to tolerate the pandemic with slight decreases in strain over time. Despite substantial variance between countries, 66% of the variance occurred between individuals. Sex, work experience, stressor appraisal, emotion regulation, and preparedness significantly predicted strain. Risk of infection and deficient communication emerged as main stressors. Officers' reports allowed to derive implications for governmental, organizational, and individual coping strategies during pandemics.

CONCLUSION

Preparing for a pandemic requires three primary paths: 1) enacting unambiguous laws and increasing public compliance through media communication, 2) being logistically prepared, and 3) improving stress regulation skills in police training.

Acute and Chronic Stress in Daily Police Service: A Three-Week N-of-1 Study

On duty, police officers are exposed to a variety of acute, threatening stress situations and organizational demands. In line with the allostatic load model, the resulting acute and chronic stress might have tremendous consequences for police officers' work performance and psychological and physical health. To date, limited research has been conducted into the underlying biological, dynamic mechanisms of stress in police service. Therefore, this ecological momentary assessment study examined the associations of stress, mood and biological stress markers of a 28-year-old male police officer in a N-of-1 study over three weeks (90 data points). Four times a day (directly after waking up, 30 minutes later, 6 hours later, before going to bed), he answered questions about the perceived stress and mood using a smartphone application. With each data entry, he collected saliva samples for the later assessment of salivary cortisol (sCort) and alpha-amylase (sAA). In addition, data was collected after six police incidents during duty. sCort and sAA were not related to perceived stress in daily life and did not increase in police incidents. Regarding mood measures, deterioration of calmness, but not valence and energy was associated with perceived stress. The results suggest continued police service to constitute a major chronic stressor resulting in an inability to mount a proper response to further acute stress. As an indicator of allostatic load, psychological and biological hyporesponsivity in moments of stress may have negative consequences for police officers' health and behavior in critical situations that require optimal performance. Prospectively, this research design may also become relevant when evaluating the efficacy of individualized stress management interventions in police training.

Patterns of occupational stress in police contact and dispatch personnel: implications for physical and psychological health

PURPOSE

Occupational stress in police call handlers is researched less frequently than in operational or frontline police, despite the role's unique challenges. Occupational stress is potentially manageable, thus improved understanding of its contributors and consequences is important for effective intervention. We aimed to compare levels and sources of organisational stress in police contact and dispatch personnel with UK benchmarks. Second, to test whether different typologies of stress were associated with physical health, mental health and substance use. Finally, to examine whether non-organisational factors (socio-demographic factors and family interference with work (FIW)) predicted organisational stress typologies.

METHODS

A sample (n = 720) of police and civilian staff in a UK police call and dispatch centre were surveyed.

RESULTS

The strongest sources of stress were competing and high demands, low control, insufficient managerial support and ambiguity surrounding workplace change-all of which indicated need for 'urgent action' according to UK benchmarks. Substance use and particularly mental health difficulties were higher than published norms. A latent profile analysis grouped respondents into a low-stress group and two high-stress profiles. As stress increased across profiles, this corresponded with worse physical and mental health and higher substance use. FIW predicted membership of both high-stress profiles.

CONCLUSION

Despite non-operational roles, police contact and despatch personnel can experience high occupational stress which is associated with physical and mental health difficulties and substance use. Organisational-level interventions which address lack of control, conflicting role demands as well as enhance management support and communication around change might be most effective in this group.

The Impact of Acute Stress Physiology on Skilled Motor Performance: Implications for Policing

Investigations of police performance during acutely stressful situations have primarily focused on higher-order cognitive processes like attention, affect or emotion and decision-making, and the behavioral outcomes of these processes, such as errors in lethal force. However, behavioral outcomes in policing must be understood as a combination of both higher-order processes and the physical execution of motor skills. What is missing from extant police literature is an understanding of how physiological responses to acute stress contribute to observed decrements in skilled motor performance at the neuromuscular level. The purpose of the current paper is to fill this knowledge gap in the following ways: (1) review scientific evidence for the physiological (i.e., autonomic, endocrine, and musculoskeletal) responses to acutely stressful exposures and their influence on skilled motor performance in both human and animal models, (2) review applied evidence on occupationally relevant stress physiology and observed motor decrements in performance among police, and (3) discuss the implications of stress physiology for police training and identify future directions for applied researchers. Evidence is compelling that skill decay is inevitable under high levels of acute stress; however, robust evidence-informed training practices can help mitigate this decay and contribute to officer safety.

Applying the Theory of Constructed Emotion to Police Decision Making

Law enforcement personnel commonly make decisions in stressful circumstances, where the costs associated with errors are high and sometimes fatal. In this paper, we apply a powerful theoretical approach, the theory of constructed emotion (TCE), to understand decision making under evocative circumstances. This theory posits that the primary purpose of a brain is to predictively regulate physiological resources to coordinate the body's motor activity and learning in the short term, and to meet the body's needs for growth, survival, and reproduction in the long term. This process of managing the brain and body's energy needs, called allostasis, is based on the premise that a brain anticipates bodily needs and attempts to meet those needs before they arise (e.g., vestibular activity that raises sympathetic nervous system activity before standing), because this is more efficient than responding to energetic needs after the fact. In this view, all mental events-cognition, emotion, perception, and action-are shaped by allostasis, and thus all decision making is embodied, predictive, and concerned with balancing energy needs. We also posit a key role for the autonomic nervous system (ANS) in regulating short-term energy expenditures, such that the ANS influences experience and behavior under stressful circumstances, including police decision making. In this paper, we first explain the core features of the TCE, and then offer insights for understanding police decision making in complex, real-world situations. In so doing, we describe how the TCE can be used to guide future studies of realistic decision making in occupations in which people commonly make decisions in evocative situations or under time pressure, such as in law enforcement.

Complex Motor Learning and Police Training: Applied, Cognitive, and Clinical Perspectives

The practices surrounding police training of complex motor skills, including the use of force, varies greatly around the world, and even over the course of an officer’s career. As the nature of policing changes with society and the advancement of science and technology, so should the training practices that officers undertake at both central (i.e., police academy basic recruit training) and local (i.e., individual agency or precinct) levels. The following review is intended to bridge the gap between scientific knowledge and applied practice to inform best practices for training complex motor skills that are unique and critical to law enforcement, including the use of lethal force. We begin by providing a basic understanding of the fundamental cognitive processes underlying motor learning, from novel skill acquisition to complex behaviors including situational awareness, and decision-making that precede and inform action. Motor learning, memory, and perception are then discussed within the context of occupationally relevant stress, with a review of evidence-based training practices that promote officer performance and physiological responses to stress during high-stakes encounters. A lack of applied research identifying the neurophysiological mechanisms underlying motor learning in police is inferred from a review of evidence from various clinical populations suffering from disorders of cognitive and motor systems, including Alzheimer’s and Parkinson’s disease and stroke. We conclude this review by identifying practical, organizational, and systemic challenges to implementing evidence-based practices in policing and provide recommendations for best practices that will promote training effectiveness and occupational safety of end-users (i.e., police trainers and officers).