Adolescent psychopathy, heart rate, and skin conductance

Can peripheral psychophysiological markers predict response to exposure-based cognitive behavioral therapy in youth with severely impairing irritability? A study protocol

BACKGROUND

Irritability, an increased proneness to anger, is a primary reason youth present for psychiatric care. While initial evidence supports the efficacy of exposure-based cognitive behavioral therapy (CBT) for youth with clinically impairing irritability, treatment mechanisms remain unclear. Here, we propose to measure peripheral psychophysiological indicators of arousal-heart rate (HR)/electrodermal activity (EDA)-and regulation-heart rate variability (HRV)-during exposures to anger-inducing stimuli as potential predictors of treatment efficacy. The objective of this study is to evaluate whether in-situ biosensing data provides peripheral physiological indicators of in-session response to exposures.

METHODS

Blood volume pulse (BVP; from which HR and HRV canl be derived) and EDA will be collected ambulatorily using the Empatica EmbracePlus from 40 youth (all genders; ages 8-17) undergoing six in-person exposure treatment sessions, as part of a multiple-baseline trial of exposure-based CBT for clinically impairing irritability. Clinical ratings of irritability will be conducted at baseline, weekly throughout treatment, and at 3-month and 6-month follow-ups via the Clinical Global Impressions Scale (CGI) and the Affective Reactivity Index (ARI; clinician-, parent-, and child-report). Multilevel modeling will be used to assess within- and between-person changes in physiological arousal and regulation throughout exposure-based CBT and to determine whether individual differences are predictive of treatment response.

DISCUSSION

This study protocol leverages a wearable biosensor (Empatica) to continuously record HR/HRV (derived from BVP) and EDA during in-person exposure sessions for youth with clinically impairing irritability. Here, the goal is to identify changes in physiological arousal (EDA, HR) and regulation (HRV) over the course of treatment in tandem with changes in clinical symptoms.

TRIAL REGISTRATION

The participants in this study come from an overarching clinical trial (trial registration numbers: NCT02531893 first registered on 8/25/2015; last updated on 8/25/2023). The research project and all related materials were submitted and approved by the appropriate Institutional Review Board of the National Institute of Mental Health (NIMH).

Examining the relation among callous-unemotional traits and cortisol, alpha-amylase, and testosterone reactivity in legal system involved young men

Elevated callous-unemotional (CU) traits (e.g., lack of empathy, deficient guilt/remorse, and shallow affect) are associated with increased antisociality and distinct patterns of cognitive and emotional functioning. Previous investigations have suggested that deficits in physiological stress responses may underlie these associations, yet few studies simultaneously examine the multiple physiological systems responsible for mounting a stress response. To clarify how individuals with and without elevated CU traits respond to acute stress, the current study examined the association between CU traits and hormones released by three systems: cortisol from the hypothalamic-pituitary-adrenal (HPA) axis, alpha-amylase from the sympathetic nervous system (SNS), and testosterone from hypothalamic-pituitary-gonadal (HPG) axis. Specifically, we used fixed effect regression modeling to examine within-individual changes in each biomarker across the administration of a standardized laboratory stressor (Trier Social Stress Test) in a sample of 55 justice-involved young men (Mage= 22.84). Results indicated significant within-individual changes in cortisol, alpha-amylase, and testosterone following the stressor among those with low or average CU traits. However, those with high levels of CU exhibited no significant changes in their cortisol and testosterone levels. Furthermore, individuals with high CU traits exhibit an asymmetric stress response, such that alpha-amylase and testosterone levels were not associated with changes in cortisol levels. In sum, elevated CU traits were associated with blunted cortisol and testosterone reactivity and asymmetric response to stress. Additional work is needed to determine the behavioral and treatment implications of this distinct stress response.

Neurobiological correlates of antisociality across adolescence and young adulthood: a multi-sample, multi-method study

BACKGROUND

Antisociality across adolescence and young adulthood puts individuals at high risk of developing a variety of problems. Prior research has linked antisociality to autonomic nervous system and endocrinological functioning. However, there is large heterogeneity in antisocial behaviors, and these neurobiological measures are rarely studied conjointly, limited to small specific studies with narrow age ranges, and yield mixed findings due to the type of behavior examined.

METHODS

We harmonized data from 1489 participants (9-27 years, 67% male), from six heterogeneous samples. In the resulting dataset, we tested relations between distinct dimensions of antisociality and heart rate, pre-ejection period (PEP), respiratory sinus arrhythmia, respiration rate, skin conductance levels, testosterone, basal cortisol, and the cortisol awakening response (CAR), and test the role of age throughout adolescence and young adulthood.

RESULTS

Three dimensions of antisociality were uncovered: 'callous-unemotional (CU)/manipulative traits', 'intentional aggression/conduct', and 'reactivity/impulsivity/irritability'. Shorter PEPs and higher testosterone were related to CU/manipulative traits, and a higher CAR is related to both CU/manipulative traits and intentional aggression/conduct. These effects were stable across age.

CONCLUSIONS

Across a heterogeneous sample and consistent across development, the CAR may be a valuable measure to link to CU/manipulative traits and intentional aggression, while sympathetic arousal and testosterone are additionally valuable to understand CU/manipulative traits. Together, these findings deepen our understanding of the fundamental mechanisms underlying different components of antisociality. Finally, we illustrate the potential of using current statistical techniques for combining multiple datasets to draw robust conclusions about biobehavioral associations.

Vocally-Encoded Emotional Arousal as a Marker of Callous-Unemotional Traits in a Sample of Justice-Involved Adolescents

Callous-unemotional (CU) traits are associated with severe and persistent juvenile offending. CU traits are also associated with dampened emotional arousal, which suggests that fundamental frequency (f0), a measure of vocally-encoded emotional arousal, may serve as an accessible psychophysiological marker of CU traits in youth. This study investigated the associations between f0 range measured during an emotionally evocative task, CU traits, and emotion dysregulation in a mixed-gender sample of 168 justice-involved youth. For boys, after controlling for covariates, wider f0 range-indicating greater emotional arousal-was negatively associated with CU traits and positively associated with emotion dysregulation. For girls, no significant associations with f0 range emerged; however, CU traits were positively associated with emotion dysregulation. Findings suggest that f0 range may serve as a valid indicator of CU traits in JJ-involved boys, and that detained boys and girls with high CU traits are characterized by different profiles of emotion dysregulation.

Fear Conditioning Deficits in Children and Adolescents with Psychopathic Traits: a Study in a Clinical Population

Deficits in fear conditioning related to psychopathy have been widely studied in adults. However, evidence in children and adolescents is scarce and inconsistent. This research aimed to expand knowledge about fear conditioning in psychopathy and its dimensions in child and early adolescent clinical populations. Participants were 45 boys (outpatients) aged 6–14 years (M = 10.59, SD = 2.04). They were assessed with the parents’ and teachers’ versions of the Child Problematic Traits Inventory (CPTI). A fear conditioning paradigm (Neumann et al., in Biological Psychology, 79(3), 337–342, 2008) for children and adolescents was used. Conditioned stimuli (CS+ and CS-) were geometric shapes and the unconditioned stimulus (US) was an unpleasant sound of metal scraping on slate (83 dB). Difference scores (CS+ minus CS-) in skin conductance responses (SCR) and self-reported cognitive and affective measures were considered as indices of fear conditioning. Results showed that: a) deficits in fear conditioning were related to some psychopathy dimensions but not to psychopathy as a unitary construct; b) the Impulsivity-Need for Stimulation dimension was a predictor of impaired fear conditioning at a cognitive level; c) the interaction of Callous-Unemotional and Impulsivity-Need for Stimulation dimensions was a significant predictor of impaired electrodermal fear conditioning; d) by contrast, the Grandiose-Deceitful dimension, was marginally associated with a greater electrodermal fear conditioning. In conclusion, psychopathy dimensions and their interactions, but not psychopathy as a whole, predicted deficits in fear conditioning as measured by SCR and cognitive indices. These findings confirm the notion that psychopathic traits are associated with deficits in fear conditioning in child and adolescent clinical populations and provide support for a multidimensional approach to youth psychopathy.

Skin Conductance Responses to a Discrete Threat in Virtual Reality: Associations with Psychopathy and Anxiety

People with high levels of psychopathic traits are often described as fearless and lacking in emotional depth, particularly when evaluating threats in their environments. Skin conductance responsivity (SCR) to negative emotional stimuli represents a robust autonomic correlate of conduct problem behavior in children (Fanti et al., in Neuroscience and Biobehavioral Reviews, 100, 98-107, 2019). However, studies that have examined threat-related processing in youth with conduct problems have tended to use a variety of negative stimuli that might induce various and unspecific negative emotions. Few studies have taken in to account the moderating effects of anxiety on the relationship of distinct psychopathic traits (e.g., narcissism, callousness, impulsivity) with SCR to a fear inducing stimulus. In this study, we examined SCR to a virtual reality rollercoaster drop - that is, a discrete fear inducing event - in a sample of 75 youths (61 males; M = 14 years, SD = 1.4) enrolled in a non-mainstream school. The rollercoaster drop was used to more clearly examine an event-related response to a discrete threat, rather than examining SCR throughout the rollercoaster ride. We used the teacher-reported Antisocial Process Screening Device (Frick & Hare, in Antisocial process screening device: APSD. Toronto: Multi-Health Systems, 2001) to examine the relations of distinct psychopathic traits with SCR and self-reported anxiety. Lower anxiety was associated with higher callousness, but only in youths with low SCR to discrete threat. These findings suggest that fear and anxiety show complex and interactive relations with distinct psychopathic traits.

Heart Rate and Skin Conductance Associations with Physical Aggression, Psychopathy, Antisocial Personality Disorder and Conduct Disorder: An Updated Meta-Analysis

The associations between physiological measures (i.e., heart rate and skin conductance) of autonomic nervous system (ANS) activity and severe antisocial spectrum behavior (AB) were meta-analyzed. We used an exhaustive partitioning of variables relevant to the ANS-AB association and investigated four highly relevant questions (on declining effect sizes, psychopathy subscales, moderators, and ANS measures) that are thought to be transformative for future research on AB. We investigated a broad spectrum of physiological measures (e.g., heart rate (variability), pre-ejection period) in relation to AB. The search date for the current meta-analysis was on January 1^st, 2020, includes 101 studies and 769 effect sizes. Results indicate that effect sizes are heterogeneous and bidirectional. The careful partitioning of variables sheds light on the complex associations that were obscured in previous meta-analyses. Effects are largest for the most violent offenders and for psychopathy and are dependent on the experimental tasks used, parameters calculated, and analyses run. Understanding the specificity of physiological reactions may be expedient for differentiating between (and within) types of AB.

Heart-wired to be cold? Exploring cardiac markers of callous-unemotional traits in incarcerated offenders

Elevated callous-unemotional (CU) traits have been repeatedly identified in a subgroup of offenders that displays severe antisocial behavior; establishing physiological markers may help improve early identification and treatment efforts. This study examines to what extent baseline-resting heart rate (HR) and heart rate variability (HRV) can be used as markers of CU in incarcerated juvenile and adult offenders. CU traits were assessed using the Inventory of Callous-Unemotional traits. Results of the multiple hierarchical regression tests indicated that there was a small yet significant positive association between baseline HR and CU and negative association between HRV and CU in juvenile offenders with medium model effect sizes (R² = 0.115 for HR-CU; R² = 0.126 for HRV-CU). The cardiac markers were unrelated to CU in adult offenders. These findings are important because they demonstrate that impaired cardiac autonomic activity is related to CU traits in juveniles, suggesting that socioemotional processing difficulties should be considered in understanding these deficits. Future research should be conducted in large samples, under reactive and static conditions, while including cardiac covariates, to get more clarity on the interplay between biological systems and behavioral expression.

Balancing the brain of offenders with psychopathy? Resting state EEG and electrodermal activity after a pilot study of brain self-regulation training

Although investigation of the brains of criminals began quite early in the history of psychophysiological research, little is known about brain plasticity of offenders with psychopathy. Building on our preliminary study reporting successful brain self-regulation using slow cortical potential (SCP) neurofeedback in offenders with psychopathy, we investigated the central nervous and autonomic peripheral changes occurring after brain self-regulation in a group of severe male offenders with psychopathy. Regarding the central nervous system, an overall suppression of the psychopathic overrepresentation of slow frequency bands was found, such as delta and theta band activity, after EEG neurofeedback. In addition, an increase in alpha band activity could be observed after the SCP self-regulation training. Electrodermal activity adaptively changed according to the regulation task, and this flexibility improved over training time. The results of this study point towards a constructive learning process and plasticity in neural and peripheral measures of offenders with psychopathy.

Reduced Electrodermal Fear Conditioning and Child Callous-Unemotional Traits

Diminished fear conditioning is a well-replicated finding in adult psychopathy. In contrast, there is virtually no research on fear conditioning and callous-unemotional (CU) traits in children. This study aimed to fill in this knowledge gap using a sample of predominantly African American children. The sample comprised 446 community-recruited children (mean age = 11.93 years; 52% boys; 82% African Americans). Skin conductance was recorded during a fear conditioning task and a resting task. CU traits were assessed using the Antisocial Processes Screening Device completed by children and their parents, while aggression was measured with the Buss-Perry Aggression Questionnaire-Short Form. Self-report, but not parent-report CU traits were inversely associated with fear conditioning skin conductance response. CU traits from either report source were not associated with skin conductance responding to the aversive stimulus, or with resting skin conductance level. This is the first study documenting an association between CU traits in children and reduced electrodermal fear conditioning. Findings highlight the importance of conditioned negative emotional arousability in CU traits, and lend support to the developmental psychopathology hypothesis that CU traits may result from impaired conscience development. Electrodermal fear conditioning has the potential to be incorporated into treatment protocols for screening and evaluation purpose.