Reduced cortical volume of the default mode network in adolescents with generalized anxiety disorder.

BACKGROUND: Widespread structural alterations have been shown to be implicated in individuals with generalized anxiety disorder (GAD). However, there have been inconsistent findings in cortical volume (CV) differences. Most structural neuroimaging studies looking at GAD used region-based approach with relatively small sample sizes, let alone be specific to adolescents with GAD. We believe this is the first study to look at CV measures using a network-based approach in a larger sample of adolescents with GAD. The goal of the current study was to focus on three different brain networks (i.e., Limbic, Frontoparietal, and Default Mode Network [DMN]) in adolescents with GAD. METHOD: The study involved 81 adolescents with GAD and 112 typically developing (TD) comparison individuals matched on age (15.98 and 15.63 respective means), sex (42F/39M and 45F/67M), and IQ (101.90 and 103.94 respective means). Participants underwent structural MRI. Freesurfer was used to estimate CV (both network-specific and region-specific within networks) and region-specific sub-cortical volume measures. Multivariate analysis of covariance (MANCOVA; with sex, age, IQ, and intracranial volume [ICV] as potential covariates) was used to estimate group differences. RESULTS: We found significantly lower CV for the DMN in adolescents with GAD, compared with TD individuals. Adolescents with GAD also showed significantly lower hemispheric mean CV of the default-mode regions (particularly the prefrontal and temporal regions) and the hippocampus, compared with TD individuals. CONCLUSION: The current findings suggest structural alterations in adolescents with GAD. These structural alterations will need to be addressed when implementing and developing treatments for patients with GAD.

Reduced neural differentiation of rewards and punishment during passive avoidance learning in adolescents with generalized anxiety disorder.

BACKGROUND: It has been proposed that individuals with generalized anxiety disorder (GAD) show dysfunctional computations related to approach-avoidance decision-making. However, few studies have examined the neural basis of this impairment, particularly in adolescents with GAD. The goal of the current study was to address this gap in the literature. METHOD: The study involved 51 adolescents with GAD and 51 typically developing (TD) comparison individuals matched on age (16.10 and 15.75 respective means), gender (30 F/21 M and 24 F/27 M), and IQ (103.20 and 103.18 respective means). Participants underwent functional magnetic resonance imaging during a passive avoidance task. RESULTS: We found a significant Group-by-Reinforcement interaction within reward-related brain regions including the caudate, putamen, mid cingulate/paracentral lobule, and superior and middle frontal gyrus. TD adolescents showed a greater differential response to reward versus punishment feedback within these regions relative to adolescents with GAD. In particular, this reflected reduced responses to rewards in the adolescents with GAD. There were no group differences in neural responses when making approach/avoidance responses. CONCLUSION: The results of this study suggest reduced differential responsiveness to reinforcement as a component of the pathophysiology seen in adolescents with GAD. This dysfunction likely underpins decision-making impairments that may exacerbate the participants' worry.

Psychopathy.

Psychopathy is a personality disorder characterized by a constellation of affective, interpersonal, lifestyle and antisocial features whose antecedents can be identified in a subgroup of young people showing severe antisocial behaviour. The prevalence of psychopathy in the general population is thought to be ~1%, but is up to 25% in prisoners. The aetiology of psychopathy is complex, with contributions of both genetic and environmental risk factors, and gene-environment interactions and correlations. Psychopathy is characterized by structural and functional brain abnormalities in cortical (such as the prefrontal and insular cortices) and subcortical (for example, the amygdala and striatum) regions leading to neurocognitive disruption in emotional responsiveness, reinforcement-based decision-making and attention. Although no effective treatment exists for adults with psychopathy, preliminary intervention studies targeting key neurocognitive disturbances have shown promising results. Given that psychopathy is often comorbid with other psychiatric disorders and increases the risk of physical health problems, educational and employment failure, accidents and criminality, the identification of children and young people at risk for this personality disorder and preventative work are important. Indeed, interventions that target the antecedents of psychopathic features in children and adolescents have been found to be effective.

Alcohol and Cannabis Use Disorder Symptom Severity, Conduct Disorder, and Callous-Unemotional Traits and Impairment in Expression Recognition.

Background: Alcohol and cannabis are commonly used by adolescents in the United States. Both alcohol use disorder (AUD) and cannabis use disorder (CUD) have been associated with reduced emotion expression recognition ability. However, this work has primarily occurred in adults and has not considered neuro-cognitive risk factors associated with conduct problems that commonly co-occur with, and precede, substance use. Yet, conduct problems are also associated with reduced emotion expression recognition ability. The current study investigated the extent of negative association between AUD and CUD symptom severity and expression recognition ability over and above any association of expression recognition ability with conduct problems [conduct disorder (CD) diagnostic status]. Methods: In this study, 152 youths aged 12.5-18 years (56 female; 60 diagnosed with CD) completed a rapid presentation morphed intensity facial expression task to investigate the association between relative severity of AUD/CUD and expression recognition ability. Results: Cannabis use disorder identification test (CUDIT) scores were negatively associated with recognition accuracy for higher intensity (particularly sad and fearful) expressions while CD diagnostic status was independently negatively associated with recognition of sad expressions. Alcohol use disorder identification test (AUDIT) scores were not significantly associated with expression recognition ability. Conclusions: These data indicate that relative severity of CUD and CD diagnostic status are statistically independently associated with reduced expression recognition ability. On the basis of these data, we speculate that increased cannabis use during adolescence may exacerbate a neuro-cognitive risk factor for the emergence of aggression and antisocial behavior.

Recent neuro-imaging findings with respect to conduct disorder, callous-unemotional traits and psychopathy.

PURPOSE OF REVIEW: To review recent neuro-imaging findings with respect to conduct disorder and callous-unemotional traits in childhood and comparable psychopathy in adult-hood that deepen the literature in important ways. RECENT FINDINGS: Recent structural findings particularly bring clarity to the literature. First, they reinforce previous work indicating that severity of psychopathy is positively associated with extent of cavum septum pellucidum. This suggests psychopathy is associated with early neurodevelopmental disruption within limbic structures. Second, they clarify the direction of the association between conduct disorder and particularly callous-unemotional traits and white matter tract abnormalities even if it remains less transparent exactly which tracts are disrupted. However, conclusions based on recent functional imaging studies are more equivocal with inconsistencies in direction of emotional (albeit with notably more work confirming the previous reports of hypo-responsiveness in limbic regions) and reward responsiveness. SUMMARY: The recent data are, for the most part, consistent with a view that callous-unemotional traits/psychopathy represents an early appearing neuro-developmental disorder particularly associated with compromised emotional (limbic) functioning. However, some patients presenting with severe antisocial behavior may also show hyper-threat sensitivity, perhaps reflecting trauma exposure, and require different clinical interventions.

Dysfunctional neurocognition in individuals with clinically significant psychopathic traits
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The main goal of this review is to consider the main forms of dysfunctional neurocognition seen in individuals with clinically significant psychopathic traits (ie, reduced guilt/empathy and increased impulsive/antisocial behavior). A secondary goal is to examine the extent to which these forms of dysfunction are seen in both adults with psychopathic traits and adolescents with clinically significant antisocial behavior that may also involve callous-unemotional traits (reduced guilt/empathy). The two main forms of neurocognition considered are emotional responding (to distress/pain cues and emotional stimuli more generally) and reward-related processing. Highly related forms of neurocognition, the response to drug cues and moral judgments, are also discussed. It is concluded that dysfunction in emotional responsiveness and moral judgments confers risk for aggression across adolescence and into adulthood. However, reduced reward-related processing, including to drug cues, is only consistently found in adolescents with clinically significant antisocial behavior, not adults with psychopathy.
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El objetivo central de este artículo es considerar las principales formas de disfunción neurocognitiva que se observan en sujetos con rasgos psicopáticos clínicamente significativos (por ejemplo, disminución de la empatía / culpa y aumento del comportamiento impulsivo / antisocial). En segundo lugar, se analiza en qué medida aparecen estas formas de disfunción tanto en adultos con rasgos psicopáticos como en adolescentes con un comportamiento antisocial clínicamente significativo que también puede implicar características insensibles / frías (disminución de la empatía / culpa). Las dos formas principales de neurocognición examinadas son la reactividad emocional (a los signos de angustia y dolor, y los estímulos emocionales en general) y el sistema de recompensa. También se discuten formas muy relacionadas de la neurocognición, como son la respuesta a estímulos de drogas y los juicios morales. En conclusión, la aparición de una disfunción en la reactividad emocional y los juicios morales confiere un riesgo de agresión durante la adolescencia y la edad adulta. Sin embargo, en adolescentes con comportamiento antisocial clínicamente significativo se encuentra de manera consistente una reducción del procesamiento relacionado con la recompensa, incluyendo la respuesta a drogas ; lo que no aparece en adultos con psicopatía.

Cet article a pour principal objectif d'envisager les principales formes de dysfonction neurocognitive observées chez des sujets présentant des traits psychopathiques cliniquement significatifs (par exemple, empathie/culpabilité réduite et comportement impulsif/antisocial majoré). Secondairement, il sera analysé dans quelle mesure ces formes de dysfonction sont observées à la fois chez des adultes ayant des traits psychopathiques et chez des adolescents ayant un comportement antisocial cliniquement significatif qui peut aussi impliquer des traits insensibles/froids (empathie/culpabilité réduite). Les deux principales formes de neurocognition examinées sont la réactivité émotionnelle (aux signes de détresse et de douleur et aux stimuli émotionnels plus généralement) et le système de récompense. Des formes de neurocognition très reliées, la réponse aux stimuli des drogues et aux jugements moraux, sont aussi discutées. En conclusion, une dysfonction observée dans la réactivité émotionnelle et les jugements moraux confère un risque pour l'agression au cours de l'adolescence et à l'âge adulte. Néanmoins, une diminution du système de récompense, y compris les stimuli des drogues, est régulièrement observée chez des adolescents au comportement antisocial cliniquement significatif et pas chez les adultes psychopathes.

Threat Responsiveness as a Function of Cannabis and Alcohol Use Disorder Severity.

Objective: Two of the most commonly abused substances by adolescents in the United States are alcohol and cannabis, both of which are associated with adverse medical and psychiatric outcomes throughout the lifespan. Both are assumed to impact the development of emotional processing although findings on the direction of this impact have been mixed. Preclinical animal work and some functional magnetic resonance imaging (fMRI) work with humans have suggested cannabis use disorder (CUD) and alcohol use disorder (AUD) are associated with increased threat responsiveness. However, other fMRI work has indicated CUD/AUD are associated with diminished threat responsiveness. In this study, we report on a study examining the relationship of severity of CUD/AUD and threat responsiveness in an adolescent population. Methods: The study involved 87 (43 male) adolescents with varying levels of CUD/AUD symptomatology (N = 45 above clinical cutoffs for CUD or AUD). They were scanned with fMRI during a looming threat task that involved images of threatening and neutral human faces or animals that appeared to be either looming or receding. Results: Increasing levels of CUD symptomatology were associated with decreased responding to looming stimuli within regions, including rostral frontal and fusiform gyrus as well as the amygdala. There were no relationships with AUD symptomatology. Conclusions: These data indicate that CUD in particular is associated with a decrease in responsiveness to the looming threat cue possibly relating to the putative neurotoxic impact of cannabis abuse.