Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

Facial affect recognition in criminal psychopaths

Prior studies provide consistent evidence of deficits for psychopaths in processing verbal emotional material but are inconsistent regarding nonverbal emotional material. To examine whether psychopaths exhibit general versus specific deficits in nonverbal emotional processing, 34 psychopaths and 33 nonpsychopaths identified with Hare's (R. D. Hare, 1991) Psychopathy Checklist--Revised were asked to complete a facial affect recognition test. Slides of prototypic facial expressions were presented. Three hypotheses regarding hemispheric lateralization anomalies in psychopaths were also tested (right-hemisphere dysfunction, reduced lateralization, and reversed lateralization). Psychopaths were less accurate than nonpsychopaths at classifying facial affect under conditions promoting reliance on right-hemisphere resources and displayed a specific deficit in classifying disgust. These findings demonstrate that psychopaths exhibit specific deficits in nonverbal emotional processing.     

Psychopathy is related to negative affectivity but not to anxiety sensitivity

Although the hypothesis that psychopathic individuals are characterized by a reduced capacity for experiencing anxiety is central to many theories of psychopathy, most prior studies have examined anxiety and fear measures generally considered outdated in the literature. Moreover, prior findings are mixed, with several studies reporting no relationships between psychopathy and anxiety, and others suggesting negative relationships for the affective, interpersonal aspects of the disorder and positive relationships for the antisocial behavior dimension. To examine whether psychopathy dimensions are associated with contemporary measures of anxiety, the Anxiety Sensitivity Index and State Trait Anxiety Inventory-Trait scale were administered to 157 male inmates. Participants also completed the MMPI-derived Welsh Anxiety Scale (WAS), commonly used in psychopathy studies. Analyses provide no evidence for a negative relationship between psychopathy's affective, interpersonal factor and anxiety sensitivity after controlling for trait anxiety. Trait anxiety and WAS scores were positively associated with the antisocial behavior dimension of psychopathy. Findings do replicate prior relationships between the WAS and psychopathy, suggesting the WAS may measure aspects of negative affectivity that differ from anxiety.     

Investigating the Components of Psychopathic Traits in Youth Offenders

Despite widespread acceptance of the importance of psychopathic traits in youth, the relative importance of different components of psychopathy remains controversial. This study was conducted to examine whether the interpersonal and lifestyle facets of psychopathy as measured with a valid clinical measure of psychopathic traits contribute to predicting relevant external criteria on top of the contributions of the affective facet. To address this issue, we conducted multiple regressions predicting antisocial behavior, exposure to violence, and psychopathology in a sample of 225 incarcerated adolescents. Results indicated that ratings on the affective component of psychopathy were important in helping to explain variance in many of the external criterion variables but that ratings on the interpersonal and lifestyle facets also helped to explain unique variance in a range of criteria including violent and non-violent crime, exposure to violence, impulsivity, and anger expression. These studies suggest that multiple components of psychopathy are likely to be important both in predicting real world outcomes and in understanding mechanisms involved in the development and manifestation of these traits.     

Facial Affect Recognition and Psychopathy: A Signal Detection Theory Perspective

Though emotional processing deficits are often conceptualized as a core feature of psychopathy, the common assessment of these deficits using the percentage correct (or hit rate) on affect recognition tasks may not provide a full or accurate picture of facial affect recognition in psychopathic individuals. Signal detection theory (SDT) provides a more informative statistical approach by providing independent measures of perceptual sensitivity (d’) and willingness to report perceiving a signal or response criterion (c). The current study employed signal detection methods to test the predictions of the integrated emotion systems and hostile attribution bias perspectives, two theoretical perspectives that make specific predictions regarding facial affect recognition. These perspectives were tested in a sample of 280 adult male incarcerated offenders who were assessed for psychopathy using the Psychopathy Checklist-Revised and who completed a novel test of facial affect recognition presenting 324 digital morphs of faces reflecting systematic combinations of pixels from neutral and affective face images (displaying six different types of emotion) as expressed by four different actors. The findings were generally not consistent with either of these perspectives. Psychopathy was negatively associated with d` for anger. Results also indicated an effect of psychopathy on response criterion for fear and effects of psychopathy on response criterion for anger and surprise that were evident only for some actors. The implications of these findings are considered through the lenses of several theoretical perspectives, and theoretical and methodological limitations of the current study are considered.

     

Effects of comorbid psychopathy on criminal offending and emotion processing in male offenders with antisocial personality disorder

Antisocial personality disorder (ASPD) and psychopathy are two syndromes with substantial construct validity. To clarify relations between these syndromes, the authors evaluated 3 possibilities: (a) that ASPD with psychopathy and ASPD without psychopathy reflect a common underlying pathophysiology; (b) that ASPD with psychopathy and ASPD without psychopathy identify 2 distinct syndromes, similar in some respects; and (c) that most correlates of ASPD reflect its comorbidity with psychopathy. Participants were 472 incarcerated European American men who met Diagnostic and Statistical Manual (4th ed., American Psychiatric Association, 1994) criteria for ASPD and Psychopathy Checklist criteria for psychopathy, who met the criteria for ASPD but not for psychopathy, or who did not meet diagnostic criteria for either ASPD or psychopathy (controls). Both individuals with ASPD only and those with ASPD and psychopathy were characterized by more criminal activity than were controls. In addition, ASPD with psychopathy was associated with more severe criminal behavior and weaker emotion facilitation than ASPD alone. Group differences in the association between emotion dysfunction and criminal behavior suggest tentatively that ASPD with and ASPD without prominent psychopathic features may be distinct syndromes.     

Assessing Interpersonal Aspects of Schizoid Personality Disorder: Preliminary Validation Studies

In 2 studies, we examined the reliability and validity of an interpersonal measure of schizoid personality disorder (SZPD) based on nonverbal behaviors and interpersonal interactions occurring during interviews. A total of 556 male jail inmates in the United States participated in Study 1; 175 mentally disordered offenders in maximum security hospitals in the United Kingdom participated in Study 2. Across both samples, scores on the Interpersonal Measure of Schizoid Personality Disorder (IM–SZ) exhibited adequate reliability and patterns of correlations with other measures consistent with expectations. The scale displayed patterns of relatively specific correlations with interview and self-report measures of SZPD. In addition, the IM–SZ correlated in an expected manner with features of psychopathy and antisocial personality and with independent ratings of interpersonal behavior. We address implications for assessment of personality disorder.     

Differentiating emotional processing and attention in psychopathy with functional neuroimaging

Individuals with psychopathy are often characterized by emotional processing deficits, and recent research has examined the specific contexts and cognitive mechanisms that underlie these abnormalities. Some evidence suggests that abnormal features of attention are fundamental to emotional deficits in persons with psychopathy, but few studies have demonstrated the neural underpinnings responsible for such effects. Here, we use functional neuroimaging to examine attention–emotion interactions among incarcerated individuals (n = 120) evaluated for psychopathic traits using the Hare Psychopathy Checklist–Revised (PCL-R). Using a task designed to manipulate attention to emotional features of visual stimuli, we demonstrate effects representing implicit emotional processing, explicit emotional processing, attention-facilitated emotional processing, and vigilance for emotional content. Results confirm the importance of considering mechanisms of attention when evaluating emotional processing differences related to psychopathic traits. The affective-interpersonal features of psychopathy (PCL-R Factor 1) were associated with relatively lower emotion-dependent augmentation of activity in visual processing areas during implicit emotional processing, while antisocial-lifestyle features (PCL-R Factor 2) were associated with elevated activity in the amygdala and related salience network regions. During explicit emotional processing, psychopathic traits were associated with upregulation in the medial prefrontal cortex, insula, and superior frontal regions. Isolating the impact of explicit attention to emotional content, only Factor 1 was related to upregulation of activity in the visual processing stream, which was accompanied by increased activity in the angular gyrus. These effects highlight some important mechanisms underlying abnormal features of attention and emotional processing that accompany psychopathic traits.     

Assessing interpersonal aspects of schizoid personality disorder: preliminary validation studies

In 2 studies, we examined the reliability and validity of an interpersonal measure of schizoid personality disorder (SZPD) based on nonverbal behaviors and interpersonal interactions occurring during interviews. A total of 556 male jail inmates in the United States participated in Study 1; 175 mentally disordered offenders in maximum security hospitals in the United Kingdom participated in Study 2. Across both samples, scores on the Interpersonal Measure of Schizoid Personality Disorder (IM-SZ) exhibited adequate reliability and patterns of correlations with other measures consistent with expectations. The scale displayed patterns of relatively specific correlations with interview and self-report measures of SZPD. In addition, the IM-SZ correlated in an expected manner with features of psychopathy and antisocial personality and with independent ratings of interpersonal behavior. We address implications for assessment of personality disorder.