Cannabis (CB) use and psychological stressors increase oxidative stress in the brain. Glutathione (GSH), the most abundant antioxidant in the brain, protects against oxidative stress. Furthermore, distress intolerance, the inability to tolerate psychological or physiological stress is a risk factor for CB use.
View Article and Find Full Text PDFAberrant neuronal excitability in the anterior cingulate cortex (ACC) is implicated in cognitive and affective pain processing. Such excitability may be amplified by activated circulating immune cells, including T lymphocytes, that interact with the central nervous system. Here, we conducted a study of individuals with chronic pain using magnetic resonance spectroscopy (MRS) to investigate the clinical evidence for the interaction between peripheral immune activation and prefrontal excitatory-inhibitory imbalance.
View Article and Find Full Text PDFBackground: Posttraumatic stress disorder (PTSD) is a psychiatric condition characterized by a prolonged stress response to potentially life-threatening events long after the event has passed. Understanding factors related to recovery from traumatic life events may inform novel targets for intervention. There is emerging preclinical evidence that creatine (Cr), a molecule critical to brain bioenergetics, may be a neurobiological marker of stress reactivity and recovery.
View Article and Find Full Text PDFCombat exposure (CE) and military sexual trauma (MST) are among the most common types of traumatic experiences faced by veterans and active duty servicemembers and, as such, have both garnered increased research focus over the past decades. However, there has not yet been a critical review of the literature to examine the distinct clinical presentations associated with different trauma types. This is particularly important, as understanding distinct clinical profiles could help researchers and clinicians refine treatment approaches based on trauma type.
View Article and Find Full Text PDFThis study explored the generality versus specificity of two trait-liability factors for externalizing problems-disinhibition and callousness-in the concurrent and prospective prediction of symptoms of conduct disorder, attention-deficit/hyperactivity disorder (ADHD), and substance use (i.e., alcohol use disorder and history of illicit substance use).
View Article and Find Full Text PDFUnderstanding factors that influence behavioral performance in high-pressure contexts is relevant to critical occupations such as first responders, military personnel, and frontline medical workers. A recent study by Yancey et al. (2019) demonstrated an association between boldness, a biobehavioral trait reflecting social dominance and fearlessness, and enhanced task-switching performance during threat of shock relative to a no-shock (safe) condition.
View Article and Find Full Text PDFTo establish a trait-dispositional variable as an indicator of liability for the development of substance use disorders (SUDs), the trait must share heritable variance with SUDs and its association should not be primarily attributable to a direct impact of SUDs on characteristics that define the trait. The current work applied a co-twin control (CTC) modeling approach to data from two monozygotic twin samples to investigate the degree to which different measures of trait-impulsiveness represent indicants of vulnerability to SUDs (liability indicators), or outcomes or concomitants of SUDs (exposure indicators). The Five Factor Model (FFM) trait of conscientiousness was assessed via self-report, and a counterpart neurobehavioral trait of disinhibition was assessed both through self-report and using self-report and brain response measures combined.
View Article and Find Full Text PDFA growing body of research supports the value of a multimodal assessment approach, drawing on measures from different response modalities, for clarifying how core biobehavioral processes relate to various clinical problems and dimensions of psychopathology. Using data for 507 healthy adults, the current study was undertaken to integrate self-report and neurophysiological (brain potential) measures as a step toward a multimodal measurement model for the trait of affiliative capacity (AFF) - a biobehavioral construct relevant to adaptive and maladaptive social-interpersonal functioning. Individuals low in AFF exhibit a lack of interpersonal connectedness, deficient empathy, and an exploitative-aggressive social style that may be expressed transdiagnostically in antagonistic externalizing or distress psychopathology.
View Article and Find Full Text PDFTo establish a trait-dispositional variable as an indicator of liability for the development of substance use disorders (SUDs), the trait must share heritable variance with SUDs and its association should not be primarily attributable to a direct impact of SUDs on characteristics that define the trait. The current work applied a co-twin control (CTC) modeling approach to data from two monozygotic twin samples to investigate the degree to which different measures of trait-impulsiveness represent indicants of vulnerability to SUDs (liability indicators), or outcomes or concomitants of SUDs (exposure indicators). The Five Factor Model (FFM) trait of conscientiousness was assessed via self-report, and a counterpart neurobehavioral trait of disinhibition was assessed both through self-report and using self-report and brain response measures combined.
View Article and Find Full Text PDFReward deficit models of addiction posit weaknesses in reward sensitivity to be promotive of substance dependence, while the externalizing spectrum model views substance problems as arising in large part from a general disinhibitory liability. The current study sought to integrate these perspectives by testing for separate and interactive associations of disinhibition and reward dysfunction with interview-assessed substance use disorders (SUDs). Community and college adults ( = 199) completed a scale measure of trait disinhibition and performed a gambling-feedback task yielding a neural index of reward sensitivity, the 'Reward Positivity' (RewP).
View Article and Find Full Text PDFThe etiology of major depressive disorder is heterogeneous, and differing pathways leading to the development of depression are proposed to account for alternative variants of depressive illness and their distinct comorbidity patterns. The present study was undertaken as a step toward developing a model for conceptualizing and quantifying dispositional proneness to depression, marked by reduced neural sensitivity to rewarding events and more persistent occurrence of depressive symptomatology. Using data for college and community adult participants (N = 201), we sought to quantify variations in depression proneness by combining symptom indicators of persistent depressive conditions (dysthymic disorder, depressive personality) with a brain potential response that has been shown to index sensitivity to pleasurable events-the reward positivity (RewP; Proudfit, 2015).
View Article and Find Full Text PDFThe Research Domain Criteria initiative aims to reorient the focus of psychopathology research toward biobehavioral constructs that cut across different modalities of measurement, including self-report and neurophysiology. Constructs within the Research Domain Criteria framework are intentionally transdiagnostic, with the construct of "acute threat," for example, broadly relevant to clinical problems and associated traits involving fearfulness and stress reactivity. A potentially valuable referent for research on the construct of acute threat is a structural model of fear/fearlessness questionnaires known to predict variations in physiological threat reactivity as indexed by startle potentiation.
View Article and Find Full Text PDFJ Exp Psychol Hum Percept Perform
June 2019
Set shifting involves the capacity to effectively and efficiently direct mental resources in the service of dynamically changing goal representations. This capacity is important in everyday life and may be vital in situations where processing resources needed for adaptive action may be diverted by cues for external danger or threat (e.g.
View Article and Find Full Text PDFCurrent literature on the relationship between dispositional fear (or threat sensitivity) and amygdala gray matter volume (GMV) is heterogeneous, with findings including positive, negative, and null correlations. A clearer understanding of this relationship would help to determine the potential utility of amygdala volume as a biomarker of anxious/depressive (internalizing) disorders and contribute to understanding of neural mechanisms for variations in fearfulness. The study reported here used voxel-based morphometry to quantify amygdala GMV scores from structural neuroimaging data in a sample of 44 monozygotic twins (i.
View Article and Find Full Text PDFPurpose: Criminological theories of crime, delinquency, and deviancy emphasize the causal role of low self-control whereas models of psychopathology posit a general trait liability, "disinhibition", contributing to persistent antisocial behavior and substance use. The aim of the current work was to link these compatible perspectives on deviancy through reference to a biobehavioral conceptualization of disinhibition.
Methods: We examined how the Grasmick et al.
Trait disinhibition, a clinical-liability construct, has well-established correlates in the diagnostic, self-rating, task-behavioral, and brain potential response domains. Recently, studies have begun to test for neuroimaging correlates of this liability factor, but more work of this type using larger data sets is needed to clarify its brain bases. The current study details the development and validation of a scale measure of trait disinhibition composed of questionnaire items available in the IMAGEN project, a large-scale longitudinal study of factors contributing to substance abuse that includes clinical interview, self-report personality, task-behavioral, neuroimaging, and genomic measures.
View Article and Find Full Text PDFThe investigation of callous-unemotional (CU) traits has been central to contemporary research on child behavior problems, and served as the impetus for inclusion of a specifier for conduct disorder in the latest edition of the official psychiatric diagnostic system. Here, we report results from 2 studies that evaluated the construct validity of callousness as assessed in adults, by testing for affiliated deficits in behavioral and neural processing of fearful faces, as have been shown in youthful samples. We hypothesized that scores on an established measure of callousness would predict reduced recognition accuracy and diminished electocortical reactivity for fearful faces in adult participants.
View Article and Find Full Text PDFRecent research initiatives have called for an increased use of biological concepts and measures in defining and studying mental health problems, but important measurement-related challenges confront efforts in this direction. This article highlights some of these challenges with reference to an intriguing measure of neural reactivity: the probe P3 response, a mid-latency brain potential evoked by an intense, unexpected acoustic-probe stimulus. Using data for a large adult sample (N=418), we report evidence that amplitude of probe P3 response to unwarned noise bursts occurring in a picture-viewing task exhibits robust, independent associations with two distinct trait constructs: weak inhibitory control (or disinhibition; DIS) and threat sensitivity (THT).
View Article and Find Full Text PDFThreat sensitivity (THT) and weak inhibitory control (or disinhibition; DIS) are trait constructs that relate to multiple types of psychopathology and can be assessed psychoneurometrically (i.e., using self-report and physiological indicators combined).
View Article and Find Full Text PDFThe National Institute of Mental Health's Research Domain Criteria (RDoC) initiative calls for the incorporation of neurobiological approaches and findings into conceptions of mental health problems through a focus on biobehavioral constructs investigated across multiple domains of measurement (units of analysis). Although the constructs in the RDoC system are characterized in "process terms" (i.e.
View Article and Find Full Text PDFThe Two-Process theory of psychopathy posits that distinct etiological mechanisms contribute to the condition: (a) a weakness in defensive (fear) reactivity related to affective-interpersonal features, and (b) impaired cognitive-executive functioning, marked by reductions in brain responses such as P3, related to impulsive-antisocial features. The current study examined relations between psychopathy factors and electrocortical response to emotional and neutral pictures in male offenders (N = 139) assessed using the Psychopathy Checklist-Revised (PCL-R). Impulsive-antisocial features of the PCL-R (Factor 2) were associated with reduced amplitude of earlier P3 brain response to pictures regardless of valence, whereas the affective-interpersonal dimension (Factor 1) was associated specifically with reductions in late positive potential response to aversive pictures.
View Article and Find Full Text PDFEnhanced startle reactivity during exposure to unpleasant cues (aversive startle potentiation; ASP) appears in the RDoC matrix as a physiological index of acute threat response. Increased ASP has been linked to focal fear disorders and to scale measures of dispositional fearfulness (i.e.
View Article and Find Full Text PDFPurpose: Classic criminological theories emphasize the role of impaired self-control in behavioral deviancy. Reduced amplitude of the P300 brain response is reliably observed in individuals with antisocial and substance-related problems, suggesting it may serve as a neurophysiological indicator of deficiencies in self-control that confer liability to deviancy.
Methods: The current study evaluated the role of self-control capacity - operationalized by scores on a scale measure of trait disinhibition - in mediating the relationship between P300 brain response and behavioral deviancy in a sample of adult twins (=419) assessed for symptoms of antisocial/addictive disorders and P300 brain response.
A crucial challenge in efforts to link psychological disorders to neural systems, with the aim of developing biologically informed conceptions of such disorders, is the problem of method variance (Campbell & Fiske, 1959). Since even measures of the same construct in differing domains correlate only moderately, it is unsurprising that large sample studies of diagnostic biomarkers yield only modest associations. To address this challenge, a construct-network approach is proposed in which psychometric operationalizations of key neurobehavioral constructs serve as anchors for identifying neural indicators of psychopathology-relevant dispositions, and as vehicles for bridging between domains of clinical problems and neurophysiology.
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