Neural substrates of trait impulsivity, anhedonia, and irritability: Mechanisms of heterotypic comorbidity between externalizing disorders and unipolar depression

Concurrent and longitudinal neurostructural correlates of irritability in children

Irritability, or an increased proneness to frustration and anger, is common in youth; however, few studies have examined neurostructural correlates of irritability in children. The purpose of the current study was to examine concurrent and longitudinal associations between brain structure and irritability in a large sample of 9-10-year-old children. Participants included 10,647 children from the Adolescent Brain Cognitive Developmentsm Study (ABCD Study®). We related a latent irritability factor to gray matter volume, cortical thickness, and surface area in 68 cortical regions and to gray matter volume in 19 subcortical regions using structural equation modeling. Multiple comparisons were adjusted for using the false discovery rate (FDR). After controlling for age, sex, race/ethnicity, scanner model, parent's highest level of education, medication use, and total intracranial volume, irritability was associated with smaller volumes in primarily temporal and parietal regions at baseline. Longitudinal analyses showed that baseline gray matter volume did not predict irritability symptoms at the 3rd-year follow-up. No significant associations were found for cortical thickness or surface area. The current study demonstrates inverse associations between irritability and volume in regions implicated in emotional processing/social cognition, attention allocation, and movement/perception. We advance prior research by demonstrating that neurostructural differences associated with irritability are already apparent by age 9-10 years, extending this work to children and supporting theories positing socioemotional deficits as a key feature of irritability.

Self-injury and suicidal behaviors in high-risk adolescents: Distal predictors, proximal correlates, and interactive effects of impulsivity and emotion dysregulation

Suicide rates are rising among U.S. youth, yet our understanding of developmental mechanisms associated with increased suicide risk is limited. One high-risk pathway involves an interaction between heritable trait impulsivity and emotion dysregulation (ED). Together, these confer increased vulnerability to nonsuicidal self-injury (NSSI), suicide ideation (SI), and suicide attempts (SAs). Previous work, however, has been limited to homogeneous samples. We extend the Impulsivity × ED hypothesis to a more diverse sample of adolescents (N = 344, ages 12-15 at Baseline, 107 males and 237 females) who were treated for major depression and assessed four times over two years. In multilevel models, the impulsivity × ED interaction was associated with higher levels and worse trajectories of NSSI, SI, and SAs. As expected, stressful life events were also associated with poorer trajectories for all outcomes, and NSSI was associated with future and concurrent SI and SAs. These findings extend one developmental pathway of risk for self-harming and suicidal behaviors to more diverse adolescents, with potential implications for prevention.

Mental health and its consequences in people living with HIV: A network approach

OBJECTIVES

Psychiatric symptoms occur frequently in people living with human immunodeficiency virus (PLWH), which may affect quality of life, sexual risk behavior, and adherence to antiretroviral therapy (ART). Data from large cohorts are limited, and symptoms are often analyzed in isolation. Therefore, we applied a network analysis to assess the interrelatedness of mental health indicators in a large cohort of PLWH.

METHODS

We included 1615 PLWH on ART. Participants reported on the severity of depression, anxiety, impulsivity, substance use, quality of life, sexual risk behavior, and ART adherence. An Ising network model was constructed to analyze interrelations between mental health indicators and connections with clinical consequences.

RESULTS

Our network analysis revealed that symptoms of depression, anxiety, and indicators of impulsivity were interrelated. Substance use was prevalent and strongly connected with sexual risk behavior. Quality of life was most strongly connected with symptoms of depression. Unexpectedly, ART adherence did not display connections with any of the mental health indicators.

CONCLUSION

In PLWH, the interrelatedness between symptoms of depression and anxiety and indicators of impulsivity is high. Mainly, depressive symptoms seem to impact quality of life, which warrants attention for depression in PLWH. We did not observe evidence for the common assumption that patients suffering from psychiatric symptoms are less adherent to HIV treatment.

Common and differential variables of anxiety and depression in adolescence: a nation-wide smartphone-based survey

BACKGROUND

Mental health in adolescence is critical in its own right and a predictor of later symptoms of anxiety and depression. To address these mental health challenges, it is crucial to understand the variables linked to anxiety and depression in adolescence.

METHODS

Here, we analyzed data of 278 adolescents that were collected in a nation-wide survey provided via a smartphone-based application during the COVID-19 pandemic. We used an elastic net regression machine-learning approach to classify individuals with clinically relevant self-reported symptoms of depression or anxiety. We then identified the most important variables with a combination of permutation feature importance calculation and sequential logistic regressions.

RESULTS

40.30% of participants reported clinically relevant anxiety symptoms, and 37.69% reported depressive symptoms. Both machine-learning models performed well in classifying participants with depressive (AUROC = 0.77) or anxiety (AUROC = 0.83) symptoms and were significantly better than the no-information rate. Feature importance analyses revealed that anxiety and depression in adolescence are commonly related to sleep disturbances (anxiety OR = 2.12, depression OR = 1.80). Differentiating between symptoms, self-reported depression increased with decreasing life satisfaction (OR = 0.43), whereas self-reported anxiety was related to worries about the health of family and friends (OR = 1.98) as well as impulsivity (OR = 2.01).

CONCLUSION

Our results show that app-based self-reports provide information that can classify symptoms of anxiety and depression in adolescence and thus offer new insights into symptom patterns related to adolescent mental health issues. These findings underscore the potentials of health apps in reaching large cohorts of adolescence and optimize diagnostic and treatment.

Non-suicidal Self-injury History Moderates the Association Between Maternal Emotional Support and Adolescent Affect During Conflict

Onset of non-suicidal self-injury (NSSI) is most frequent during adolescence. Etiological models indicate that abnormal affective reactivity and regulation within interpersonal contexts is related to heightened NSSI risk. The current study examined the effects of maternal emotional support on adolescent sympathetic nervous system (SNS) activity and observed anger during a conflict discussion among 56 mother-daughter dyads consisting of healthy adolescents and adolescents with a history of self-injury. During the conflict discussion task, maternal emotional support and adolescent anger were coded from behavior, and cardiovascular pre-ejection period was used to index SNS responding. Results demonstrated that maternal emotional support was negatively associated with adolescent anger and SNS activity during the conflict. However, these associations were not significant among adolescents with heightened NSSI history. Maternal emotional support may serve as an interpersonal mechanism for adolescent physiological and behavioral regulation, yet may function differently among adolescents with more frequent NSSI.

Functional neuroimaging biomarkers of anhedonia response to escitalopram plus adjunct aripiprazole treatment for major depressive disorder

BACKGROUND

Identifying neuroimaging biomarkers of antidepressant response may help guide treatment decisions and advance precision medicine.

AIMS

To examine the relationship between anhedonia and functional neurocircuitry in key reward processing brain regions in people with major depressive disorder receiving aripiprazole adjunct therapy with escitalopram.

METHOD

Data were collected as part of the CAN-BIND-1 study. Participants experiencing a current major depressive episode received escitalopram for 8 weeks; escitalopram non-responders received adjunct aripiprazole for an additional 8 weeks. Functional magnetic resonance imaging (on weeks 0 and 8) and clinical assessment of anhedonia (on weeks 0, 8 and 16) were completed. Seed-based correlational analysis was employed to examine the relationship between baseline resting-state functional connectivity (rsFC), using the nucleus accumbens (NAc) and anterior cingulate cortex (ACC) as key regions of interest, and change in anhedonia severity after adjunct aripiprazole.

RESULTS

Anhedonia severity significantly improved after treatment with adjunct aripiprazole.There was a positive correlation between anhedonia improvement and rsFC between the ACC and posterior cingulate cortex, ACC and posterior praecuneus, and NAc and posterior praecuneus. There was a negative correlation between anhedonia improvement and rsFC between the ACC and anterior praecuneus and NAc and anterior praecuneus.

CONCLUSIONS

Eight weeks of aripiprazole, adjunct to escitalopram, was associated with improved anhedonia symptoms. Changes in functional connectivity between key reward regions were associated with anhedonia improvement, suggesting aripiprazole may be an effective treatment for individuals experiencing reward-related deficits. Future studies are required to replicate our findings and explore their generalisability, using other agents with partial dopamine (D2) agonism and/or serotonin (5-HT2A) antagonism.

Inflamed but not impulsive: Acute inflammatory cytokine response does not impact prepotent response inhibition

BACKGROUND

Prior evidence has linked inflammation with impulsivity, but most of this evidence is cross-sectional. In this study, we provoked an acute inflammatory cytokine response to see whether it lowered prepotent response inhibition on three cognitive tasks.

METHOD

This study features secondary analyses from a randomized crossover trial in which 171 postmenopausal breast cancer survivors (Stage I-IIIA) each received a typhoid capsular polysaccharide vaccination and a saline placebo injection in a random sequence at two separate visits at least one month apart. Participants completed the Stroop Color-Discrepant Task, the 2-back, and the Conners Continuous Performance Test (CPT) on the computer between 5 and 7 h after the injections. They had their blood drawn once before and repeatedly after the injection to measure interleukin-1 receptor antagonist and interleukin-6 responses.

RESULTS

Women committed marginally fewer errors on the Stroop color-discrepant trials after the typhoid vaccine (M = 0.36, SE = 0.08), compared to placebo (M = 0.54, SE = 0.09, p = .076). Injection type did not predict 2-back accuracy (p = .80) or CPT commission errors (p = .47). Inflammatory cytokine responses were also unrelated to the outcomes of interest (ps>.16).

CONCLUSION

We found no evidence that an acute inflammatory cytokine response provokes response disinhibition - an important facet of impulsivity. In fact, our only marginally non-significant result suggested that women were better able to inhibit their prepotent responses on the Stroop after receiving the typhoid vaccine, compared to placebo. Further experimental tests of the acute inflammatory cytokine response's effect on other aspects of impulsivity are warranted.

LIMITATIONS

The sample was female, primarily White, highly educated cancer survivors, and recruitment was not premised on impulsive traits or diagnosis with an impulsive-related disorder. Also, there are many facets of impulsivity, and this study only measured response inhibition.

Beyond the RewP: The reward feedback-elicited LPP and its potential associations with perceived stress and internalizing symptoms in late childhood

Internalizing problems increase substantially during late childhood and early adolescence, which are known to be associated with elevated perceived stress as children transition into adolescence. One risk factor that may moderate the stress-symptom association is reward processing. While neurophysiological research in this field has focused on the reward positivity component (RewP) elicited during reward processing, little work has examined the reward feedback-elicited late positive potential (LPP) and its association with internalizing psychopathology. The present study examined the moderating roles of the RewP and feedback-elicited LPP in the relationship between perceived stress and internalizing symptoms in late childhood. A community sample of 115 nine-to-12-year-old children (66 girls, Mean age = 11.00 years, SD = 1.16) completed an EEG version of the reward feedback paradigm, the Doors task, and completed questionnaires on perceived stress and internalizing symptoms. A principal component analysis revealed three temporo-spatial factors that were temporally and spatially analogous to the RewP, anterior LPP, and posterior LPP, respectively. As expected, an enlarged RewP was found towards the win condition compared to the loss condition. We also observed a potentiated LPP towards loss relative to win feedback, which may reflect the evaluation and reappraisal processes following unsuccessful performance (i.e., loss). We did not, however, find significant moderating effects of any ERP components on the stress-symptom association. Our study was first to isolate the feedback-elicited LPP in a reward processing paradigm in children and provide initial evidence on the modulation of the ERP component by task conditions. Future research is warranted to further explore the functional significance of the reward feedback-elicited LPP in association with perceived stress and internalizing psychopathology in youths.

Validation of the Arabic version of the brief irritability test (Ar-BITe) in non-clinical adolescents

BACKGROUND

Despite the substantial clinical relevance of irritability in the development and maintenance of several mental disorders and its negative effects on functioning, no valid and reliable measures are available yet to identify the presence and consequences of irritability as a distinct construct among the Arabic-speaking populations. To bridge this gap, and help advance this field in the under-researched Arab region, we aimed to validate an Arabic-language version of the Brief Irritability Test (BITe).

METHODS

Eligible participants were native Arabic-speaking non-clinical adolescents from Lebanon; 527 participants aged 15.73 ± 1.81 years (56% females) completed the survey.

RESULTS

Utilizing the Confirmatory Factor Analysis approach, we found that the five items of the Arabic BITe loaded into a single factor structure. The scale showed excellent reliability, as both Cronbach's alpha and McDonald's omega coefficient values were of 0.88. Multi-group analyses showed invariance across sex groups in our sample at the configural, metric, and scalar levels. Female adolescents exhibited higher BITe scores than their male counterparts (14.01 vs. 13.25), but this difference did not reach the statistical significance. Good concurrent validity was supported based on positive correlations between irritability scores and measures of aggression, anger and hostility (r Pearson's coefficients ranging from 0.35 to 0.42), as well as positive correlations with insomnia symptoms scores.

CONCLUSION

The present findings allow us to conclude that the Arabic version of the BITe is a unidimensional, reliable, valid, brief, and economic self-report measure of the irritability construct for both male and female Arabic-speakers. Providing an Arabic validated version of the BITe will hopefully foster the research efforts of the Arab scientific community in this area, and promote the implementation of timely, evidence-informed and culturally-sensitive mental health interventions that appropriately address irritability-related problems and consequences among Arab young populations.

A comparison of ICD-11 and DSM-5 criteria of PTSD among Chinese trauma-exposed adolescent samples

This study aimed at comparing the prevalence and comorbidity differences of PTSD according to ICD-11 and DSM-5 definitions across two Chinese adolescent trauma-exposed samples. A total of 1,201 students exposed to earthquake and 559 students from vocational schools exposed to potentially traumatic events were included in this study. The PTSD Checklist for DSM-5 was used to measure PTSD symptoms. The MDD and GAD subscales of the Revised Children's Anxiety and Depression Scale were used to measure major depression disorder (MDD) and generalized anxiety disorder (GAD) symptoms. No significant PTSD prevalence differences between ICD-11 and DSM-5 were found across the two samples. The differences regarding comorbidities between ICD-11 and DSM-5 definitions were not significant among these two samples. The results revealed that the ICD-11 and DSM-5 provided similar prevalence of PTSD and comorbidity rates with MDD and GAD in Chinese trauma-exposed adolescent samples. This study contributes to the current understanding of the similarities and differences using different PTSD criteria and informs the organization and application of these two globally applied PTSD criteria.

Abnormal functional connectivity of the nucleus accumbens subregions mediates the association between anhedonia and major depressive disorder

BACKGROUND

The nucleus accumbens (Nac) is a crucial brain region in the pathophysiology of major depressive disorder (MDD) patients with anhedonia. However, the relationship between the functional imaging characteristics of Nac subregions and anhedonia remains unclear. Thus, this study aimed to investigate the role of resting-state functional connectivity (rsFC) of the Nac subregions between MDD and anhedonia.

METHODS

We performed resting-state functional magnetic resonance imaging (fMRI) to measure the rsFC of Nac subregions in 55 MDD patients and 30 healthy controls (HCs). A two-sample t test was performed to determine the brain regions with varying rsFC among Nac subregions between groups. Then, correlation analyses were carried out to investigate the relationships between the aberrant rsFC of Nac subregions and the severity of anhedonia. Furthermore, we constructed a mediation model to explain the role of the aberrant rsFC of Nac subregions between MDD and the severity of anhedonia.

RESULTS

Compared with the HC group, decreased rsFC of Nac subregions with regions of the prefrontal cortex, insula, lingual gyrus, and visual association cortex was observed in MDD patients. In the MDD group, the rsFC of the right Nac shell-like subregions with the middle frontal gyrus (MFG)/superior frontal gyrus (SFG) was correlated with consummatory anhedonia, and the rsFC of the Nac core-like subdivisions with the inferior frontal gyrus (IFG)/insula and lingual gyrus/visual association cortex was correlated with anticipatory anhedonia. More importantly, the functional alterations in the Nac subregions mediated the association between anhedonia and depression.

CONCLUSIONS

The present findings suggest that the functional alteration of the Nac subregions mediates the association between MDD and anhedonia, which provides evidence for the hypothesis that MDD patients have neurobiological underpinnings of reward systems that differ from those of HCs.

Developmental trajectories of delay discounting from childhood to young adulthood: longitudinal associations and test-retest reliability

Delay discounting (DD) indexes an individual's preference for smaller immediate rewards over larger delayed rewards, and is considered a form of cognitive impulsivity. Cross-sectional studies have demonstrated that DD peaks in adolescence; longitudinal studies are needed to validate this putative developmental trend, and to determine whether DD assesses a temporary state, or reflects a more stable behavioral trait. In this study, 140 individuals aged 9-23 completed a delay discounting (DD) task and cognitive battery at baseline and every-two years thereafter, yielding five assessments over approximately 10 years. Models fit with the inverse effect of age best approximated the longitudinal trajectory of two DD measures, hyperbolic discounting (log[k]) and area under the indifference-point curve (AUC). Discounting of future rewards increased rapidly from childhood to adolescence and appeared to plateau in late adolescence for both models of DD. Participants with greater verbal intelligence and working memory displayed reduced DD across the duration of the study, suggesting a functional interrelationship between these domains and DD from early adolescence to adulthood. Furthermore, AUC demonstrated good to excellent reliability across assessment points that was superior to log(k), with both measures demonstrating acceptable stability once participants reached late adolescence. The developmental trajectories of DD we observed from childhood through young adulthood suggest that DD may index cognitive control more than reward sensitivity, and that despite modest developmental changes with maturation, AUC may be conceptualized as a trait variable related to cognitive control vs impulsivity.

Multiple needs and multiple treatments. What's a clinician to do? Update on the psychosocial treatment of disruptive behaviours in childhood

PURPOSE OF REVIEW

There are a wide range of psychosocial treatment options, delivered in different modalities, for children with disruptive behaviour. However, clinicians face many challenges in ensuring the empirically supported treatments (ESTs) they select will be effective for their patient. This has prompted studies to generate knowledge on how to improve treatment outcomes for children with disruptive behaviour. This review identifies the major challenges in treatment selection as well as emerging research seeking to improve outcomes.

RECENT FINDINGS

This review emphasizes the salience of the research-practice gap associated with establishing ESTs using narrow definitions of clinical problems. Recent research is reviewed considering the complex determinants of disruptive behaviours, including parent and family factors that influence outcomes. The review subsequently outlines recent advances in research and clinical practice guidelines aiming to surmount these challenges. Key advances discussed include examining the most impactful components of ESTs, personalizing interventions by targeting core dysfunction underlying behaviour, and addressing parent factors including mental health and cultural relevance to improve outcomes.

SUMMARY

Thorough assessment of patients' needs, combined with knowledge of treatment response predictors, are recommended to determine the most suitable treatment plan. Recent advances have focused on developing and designing interventions that meet needs in a way that is flexible and tailored.

A Developmental Perspective on Facets of Impulsivity and Brain Activity Correlates From Adolescence to Adulthood

BACKGROUND

On a theoretical level, impulsivity represents a multidimensional construct associated with acting without foresight, inefficient inhibitory response control, and alterations in reward processing. On an empirical level, relationships and changes in associations between different measures of impulsivity from adolescence into young adulthood and their relation to neural activity during inhibitory control and reward anticipation have not been fully understood.

METHODS

We used data from IMAGEN, a longitudinal multicenter, population-based cohort study in which 2034 healthy adolescents were investigated at age 14, and 1383 were reassessed as young adults at age 19. We measured the construct of trait impulsivity using self-report questionnaires and neurocognitive indices of decisional impulsivity. With functional magnetic resonance imaging, we assessed brain activity during inhibition error processing using the stop signal task and during reward anticipation in the monetary incentive delay task. Correlations were analyzed, and mixed-effect models were fitted to explore developmental and predictive effects.

RESULTS

All self-report and neurocognitive measures of impulsivity proved to be correlated during adolescence and young adulthood. Further, pre-supplementary motor area and inferior frontal gyrus activity during inhibition error processing was associated with trait impulsivity in adolescence, whereas in young adulthood, a trend-level association with reward anticipation activity in the ventral striatum was found. For adult delay discounting, a trend-level predictive effect of adolescent neural activity during inhibition error processing emerged.

CONCLUSIONS

Our findings help to inform theories of impulsivity about the development of its multidimensional nature and associated brain activity patterns and highlight the need for taking functional brain development into account when evaluating neuromarker candidates.

Transdiagnostic Clinical Staging for Childhood Mental Health: An Adjunctive Tool for Classifying Internalizing and Externalizing Syndromes that Emerge in Children Aged 5-11 Years

Clinical staging is now recognized as a key tool for facilitating innovation in personalized and preventative mental health care. It places a strong emphasis on the salience of indicated prevention, early intervention, and secondary prevention of major mental disorders. By contrast to established models for major mood and psychotic syndromes that emerge after puberty, developments in clinical staging for childhood-onset disorders lags significantly behind. In this article, criteria for a transdiagnostic staging model for those internalizing and externalizing disorders that emerge in childhood is presented. This sits alongside three putative pathophysiological profiles (developmental, circadian, and anxious-arousal) that may underpin these common illness trajectories. Given available evidence, we argue that it is now timely to develop a transdiagnostic staging model for childhood-onset syndromes. It is further argued that a transdiagnostic staging model has the potential to capture more precisely the dimensional, fluctuating developmental patterns of illness progression of childhood psychopathology. Given potential improvements in modelling etiological processes, and delivering more personalized interventions, transdiagnostic clinical staging for childhood holds much promise for assisting to improve outcomes. We finish by presenting an agenda for research in developments of transdiagnostic clinical staging for childhood mental health.

Are sick people really more impulsive?: Investigating inflammation-driven impulsivity

In both animals and humans, inflammatory stimuli - especially infections and endotoxin injections - cause "sickness behaviors," including lethargy, malaise, and low mood. An emerging line of research asserts that inflammation may provoke present-focused decision making and impulsivity. The current article assesses that claim in the context of the broader literature - including preclinical models and clinical interventions. This literature presents three challenges to purported inflammation-impulsivity link that have not been addressed to date: (1) the nebulous and imprecise definition of impulsivity; (2) reverse causality; and (3) a lack of causal evidence. These challenges point to ways in which future research designs can improve upon the extant literature to further explore the ostensible relationship between inflammation and impulsivity.

Confirmatory Factor Analysis of Comorbidity between Depression and Aggression in a Child-Adolescent Community Sample: Nosological, Prognosis and Etiological Implications

Comorbidity between depression and aggression in the child-adolescent population remains a controversial phenomenon. To our knowledge, no longitudinal study using structural equation modeling (SEM) has confirmed whether the relationship between depression and aggression is due to the fact that they share internalizing and externalizing supraordinal factors at the level of the syndrome or is due to the fact that they share common characteristics in relation to an underlying factor at the level of symptoms. We examined longitudinal comorbid relationships in a community sample (N = 251) at three waves ages from 10 to 13 years. The SEM showed that longitudinally, the comorbidity between depression and aggression is due to the fact that they share characteristics of the same underlying factor at the symptom level. These results have implications for the classification, diagnosis, and treatment of comorbidity between depression and aggression in a child-adolescent population.

Attention-Deficit/Hyperactivity Disorder Symptoms and Externalizing Progression in the LAMS Study: A Test of Trait Impulsivity Theory

OBJECTIVE

To test differential prospective prediction of growth in externalizing behavior, including oppositional defiant disorder, conduct disorder, and substance use disorders, by earlier hyperactive-impulsive (HI) vs inattentive (IN) symptoms of attention-deficit/hyperactivity disorder (ADHD).

METHOD

Participants in the Longitudinal Assessment of Manic Symptoms (LAMS) Study (N = 685 at study entry), including 458 boys and 227 girls ages 6-12, completed full parent report and self-report assessments every year for 8 years on the Schedule for Affective Disorders and Schizophrenia for School-Age Children. Three sets of analyses were conducted. First, hierarchal regression (block entry) was used to test independent associations between HI symptoms and later externalizing outcomes, controlling for IN symptoms, and IN symptoms and later externalizing outcomes, controlling for HI symptoms. Second, logistic regression was used to test progression of DSM externalizing disorders. Third, tests of mediation were used to assess potentiation of externalizing progression through environmental risk mediators (eg, family environment, neighborhood violence).

RESULTS

Consistent with hypotheses derived from trait impulsivity theories of externalizing behavior, HI symptoms of ADHD were associated independently with long-term externalizing outcomes, whereas IN symptoms were not. Between months 48 and 96, ADHD-HI/combined symptom subtype diagnoses predicted later oppositional defiant disorder diagnoses, oppositional defiant disorder diagnoses predicted later conduct disorder diagnoses, and conduct disorder diagnoses predicted later substance use disorder diagnoses. Evidence for environmental risk mediation (eg, parental monitoring, neighborhood violence) was also found.

CONCLUSION

Findings support trait impulsivity models of externalizing progression, whereby ADHD-HI/combined symptoms subtypes predispose to increasingly severe externalizing behaviors, which are magnified in contexts of environmental risk.

Internalizing-externalizing comorbidity and regional brain volumes in the ABCD study

Despite nonoverlapping diagnostic criteria, internalizing and externalizing disorders show substantial comorbidity. This comorbidity is attributable, at least in part, to transdiagnostic neuroaffective mechanisms. Both unipolar depression and externalizing disorders are characterized by structural and functional compromises in the striatum and its projections to the anterior cingulate cortex (ACC) and other frontal regions. Smaller volumes and dampened reward responding in these regions are associated with anhedonia and irritability - mood states that cut across the internalizing and externalizing spectra. In contrast, smaller amygdala volumes and dampened amygdala function differentiate externalizing disorders from internalizing disorders. Little is known, however, about associations between internalizing-externalizing comorbidity and brain volumes in these regions, or whether such patterns differ by sex. Using a transdiagnostic, research domain criteria (RDoC)-informed approach, we evaluate associations between heterotypic (Internalizing × Externalizing) symptom interactions and striatal, amygdalar, and ACC volumes among participants in the Adolescent Brain Cognitive Development study (N = 6,971, mean age 9.9 years, 51.6% female). Heterotypic symptoms were associated with ACC volumes for both sexes, over and above the main effects of internalizing and externalizing alone. However, heterotypic comorbidity was associated with larger ACC volumes for girls, but with smaller ACC volumes for boys. These findings suggest a need for further studies and transdiagnostic assessment by sex.

Network-wise surface-based morphometric insight into the cortical neural circuitry underlying irritability in adolescents

Previous studies examining structural brain correlates of irritability have taken a region-specific approach and have been relatively inconsistent. In a sample of adolescents with and without clinically impairing irritability, the current study examines: (i) cortical volume (CV) in canonical functional networks; (ii) the association between the CV of functional networks and severity of irritability; and (iii) the extent to which IQ mediates the association between structural abnormalities and severity of irritability. Structural MRI and IQ data were collected from 130 adolescents with high irritability (mean age = 15.54±1.83 years, 58 females, self-reported Affective Reactivity Index [ARI] ≥ 4) and 119 adolescents with low irritability (mean age = 15.10±1.93 years, 39 females, self-reported ARI < 4). Subject-specific network-wise CV was estimated after parcellating the whole brain into 17 previously reported functional networks. Our Multivariate Analysis of Covariance (MANCOVA) revealed that adolescents with high irritability had significantly reduced CV of the bilateral control and default-mode networks (p < 0.05) relative to adolescents with low irritability. Multiple regression analyses showed a significant negative association between the control network CV and the severity of irritability. Mediation analysis showed that IQ partially mediated the association between the control network CV and the severity of irritability. Follow-up analysis on subcortical volume (SCV) showed that adolescents with high irritability had reduced bilateral SCV within the amygdala relative to adolescents with low irritability. Reduced CV within bilateral control and default networks and reduced SCV within bilateral amygdala may represent core features of the pathophysiology of irritability. The current data also indicate the potential importance of a patient's IQ in determining how pathophysiology related to the control network is expressed.

[Ordalie, sensation-seeking and impulsivity. Critical analysis of definitions]

BACKGROUND

In the fields of psychology and psychiatry, the use of the terms impulsivity, sensation-seeking and ordalie to refer to risk-taking behaviors can sometimes be confusing.

OBJECTIVE

The objective of this study was to establish a clinical definition of the concepts of ordalie, sensation-seeking and impulsivity, in order to analyze the similarities and differences between these concepts.

METHODS

We prioritized literature review articles with or without meta-analysis from the Medline database and supplemented with the Google-Scholar database. The articles were included in this review if their objectives were in line with ours. The research was conducted in November 2018.

RESULTS

Twenty-seven articles were selected. There are similarities in the clinical definitions of these concepts with measurable heterogeneous constructions, and an exacerbation in adolescence for engagement in harmful behaviors, but there are also nuances that highlight their differences.

CONCLUSION

We were able to describe areas of divergence and convergence between these three concepts but not to establish a quantitative diagram of the areas of divergence and convergence. It would seem that the coexistence of sensation-seeking and impulsivity in the same individual could explain that individual's involvement in ordalique behaviors. Further studies approaching this hypothesis would seem useful in terms of preventing risk-taking behaviors such as addictive behaviors.

Irritability and Inattention Not Sad Low Mood Predict Impulsiveness in Children and Adolescents With Major Depressive Disorder and Persistent Depressive Disorder

ABSTRACT

The specific relationships between impulsiveness, inattention, sad, low mood, and irritability have not been systematically examined in young people with major depressive disorder with and without persistent depressive disorder. The relationships are important to clarify because these symptom dimensions may increase suicidal risk in children and adolescents with these depressive disorders. A total of 313 medication-naive young people (aged 6-16 years) with active major depressive disorder (MDD) alone, persistent depressive disorder (DD) alone, and comorbid MDD and DD were identified. "Inattention," "sad/unhappy," and "irritable" mood were identified by parent standardized questionnaire. Standard multiple regression was used to investigate how well inattention, sad/unhappy, and irritable mood predict impulsiveness. Inattention (32% of the variance, increased) and irritable mood (5% of the variance, increased) both made independent significant contributions to impulsiveness, whereas sad/unhappy mood did not. Decreasing irritability via more targeted and comprehensive management approaches may ameliorate impulsiveness in young people with these depressive disorders.

Irritability in Mood Disorders: Neurobiological Underpinnings and Implications for Pharmacological Intervention

Feeling irritable is a common experience, both in health and disease. In the context of psychiatric illnesses, it is a transdiagnostic phenomenon that features across all ages, and often causes significant distress and impairment. In mood disorders, irritability is near ubiquitous and plays a central role in diagnosis and yet, despite its prevalence, it remains poorly understood. A neurobiological model of irritability posits that, in children and adolescents, it is consequent upon deficits in reward and threat processing, involving regions such as the amygdala and frontal cortices. In comparison, in adults with mood disorders, the few studies that have been conducted implicate the amygdala, orbitofrontal cortices, and hypothalamus; however, the patterns of activity in these areas are at variance with the findings in youth. These age-related differences seem to extend to the neurochemistry of irritability, with links between increased monoamine transmission and irritability evident in adults, but aberrant levels of, and responses to, dopamine in youth. Presently, there are no specific treatments that have significant efficacy in reducing irritability in mood disorders. However, treatments that hold some potential and warrant further exploration include agents that act on serotonergic and dopaminergic systems, especially as irritability may serve as a prognostic indicator for overall clinical responsiveness to specific medications. Therefore, for understanding and treatment of irritability to advance meaningfully, it is imperative that an accurate definition and means of measuring irritability are developed. To achieve this, it is necessary that the subjective experience of irritability, both in health and illness, is better understood. These insights will inform an accurate, comprehensive, and valid interrogation of the qualities of irritability in health and illness, and allow not only a clinical appreciation of the phenomenon, but also a deeper understanding of its important role within the development and manifestation of mood disorders.

Anhedonia and the Relationship Between Other Depressive Symptoms and Aggressive Behavior

Depression has been linked to multiple forms of aggressive behavior in college students; however, it is unclear which aspects of depression explain this connection. Anhedonia, defined as the loss of interest and/or pleasure in previously enjoyed activities, may provide unique information about relationships between depression and aggression. Using cross-sectional data from two independent samples of college students (N = 747 and N = 736 for Study 1 and Study 2, respectively), we examined whether anhedonia helped explain the relationship between broader depressive symptoms and different forms of aggressive and antisocial behavior. Anhedonia accounted for variance in both self-directed aggression and antisocial behavior independent of gender, hostility, anger, other depressive symptoms, and cognitive distortions (Study 2). In addition, there were significant indirect effects of depressive symptoms on self-directed aggression (Studies 1 and 2) and antisocial behavior (Study 2) via anhedonia. Hypotheses involving other-directed aggression received mixed support, with anhedonia atemporally associated with other-directed aggression independent of broader depressive symptoms in Study 1, but not in Study 2. The current findings suggest that anhedonia is an important individual difference that helps explain the relationship between depression and aggressive and antisocial acts and that anhedonia may be differentially associated with various types of aggressive and antisocial behavior.

Anhedonia correlates with functional connectivity of the nucleus accumbens subregions in patients with major depressive disorder

BACKGROUND

The nucleus accumbens (NAc) is an important region in reward circuit that has been linked with anhedonia, which is a characteristic symptom of major depressive disorder (MDD). However, the relationship between the functional connectivity of the NAc subregions and anhedonia in MDD patients remains unclear.

METHODS

We acquired resting-state functional magnetic resonance imaging (fMRI) scans from fifty-one subjects (23 MDD patients and 28 healthy controls). We assessed subjects' trait anhedonia with the Temporal Experience of Pleasure Scale (TEPS). Seed-based resting-state functional connectivity (rsFC) was conducted for each of the NAc subregions (bilateral core-like and shell-like subdivisions) separately to identify regions whose rsFCs with the NAc subregions were altered in the MDD patients and regions whose rsFCs with the NAc subregions showed different correlates with anhedonia between the MDD patients and the healthy controls.

RESULTS

Compared with the health controls, the MDD patients showed decreased rsFCs of the right NAc core-like subdivision with the left mid-anterior orbital prefrontal cortex and the right inferior parietal lobe as well as decreased rsFC of the left NAc core-like subdivision with the right middle frontal gyrus. Moreover, the severity of anhedonia by the group interaction was significant for the rsFC of the right NAc shell-like subdivision with the subgenual/pregenual anterior cingulate cortex and the rsFC of the right NAc core-like subdivision with the precuneus.

CONCLUSIONS

We found that the neural correlates of anhedonia indicated by the rsFCs of the NAc subregions were modulated by depression. The modulation effect was regionally-dependent. These findings enrich our understanding of the neural basis of anhedonia in MDD.

Modulation of control: Can HD-tDCS targeting the dACC reduce impulsivity?

BACKGROUND

The dorsal anterior cingulate cortex (dACC) and its neurocircuits are central in impulsivity, and maladaptive dACC activity has been implicated in psychological disorders characterized by high trait impulsivity. High-Definition transcranial Direct Current Stimulation (HD-tDCS) is a non-invasive neuromodulation tool that, with certain electrode configurations, can be optimized for targeting deeper subcorticalbrainstructures, such as the dACC.

OBJECTIVES

Using behavioural and electrophysiological measures we investigated whether HD-tDCS targeting the dACC could modulate two key components of impulsivity, inhibitory control and error processing.

METHODS

Twenty-three healthy adults with high trait impulsivity participated in two experimental sessions. Participants received active or sham HD-tDCS in counterbalanced order with a wash-out period of at least 3 days, as part of a single-blind, cross-over design. EEG was recorded during the Go-NoGo task before, directly after, and 30 min after HD-tDCS.

RESULTS

HD-tDCS targeting the dACC did not affect inhibitory control performance on the Go-NoGo task, but there was evidence for a delayed change in underlying neurophysiological components of motor inhibition (NoGo P3) and error processing (error related negativity; ERN) after one session of HD-tDCS.

CONCLUSION

HD-tDCS has potential to modulate underlying neurophysiological components of impulsivity. Future studies should further explore to what degree the dACC was affected and whether multi-session HD-tDCS has the capacity to also induce behavioural changes, particularly in clinical samples characterized by high trait impulsivity.

Neural mechanisms of reward processing in adolescent irritability

Irritability is impairing and prevalent across pediatric psychiatric disorders and typical development, yet its neural mechanisms are largely unknown. This study evaluated the relation between adolescent irritability and reward-related brain function as a candidate neural mechanism. Adolescents from intervention-seeking families in the community (N = 52; mean age = 13.80, SD = 1.94) completed a monetary incentive delay task to assess reward anticipation and feedback (reward receipt and omission) during fMRI acquisition. Whole-brain analyses, controlling for age, examined brain activation and striatal and amygdala connectivity in relation to irritability. Irritability was measured using the parent- and youth-reported Affective Reactivity Index. Irritability was associated with altered reward processing-related activation and connectivity in multiple networks during reward anticipation and feedback, including increased striatal activation and altered ventral striatum connectivity with prefrontal areas. Our findings suggest that irritability is associated with altered neural patterns during reward processing and that aberrant prefrontal cortex-mediated top-down control may be related to irritability. These findings inform our understanding of the etiology of youth irritability and the development of mechanism-based interventions.

Internet Addiction among Young Adult University Students: The Complex Interplay between Family Functioning, Impulsivity, Depression, and Anxiety

International research has underlined that both interpersonal, self-regulation, and comorbid variables can lead to a higher risk of developing internet addiction (IA) among young adults. To date, no studies have explored the interplay between young adults’ family functioning, impulsivity, and psychopathological difficulties. In a community sample of 244 young adult university students, this study aims to assess the relationship between young adults’ IA and young adults’ gender, the perception of their family functioning, impulsivity level, and depressive and anxiety symptoms, considering the possible interplay between these variables. The presence and the severity of IA were addressed through the Internet Addiction Test (IAT). Moreover, young adults filled out self-reporting questionnaires, assessing their perception of family functioning and their impulsivity levels and psychopathological symptoms. Results showed no significant association between the youth’s gender and IA. However, moderately addicted young adults were more likely to report poorer quality of family affective involvement and higher attentional impulsivity and depressive problems than other groups. Moreover, young adults’ attentional impulsivity mediated the relationship between family affective involvement and IA. This study provides new evidence on the complex interaction between individuals and interpersonal risk factors involved in IA among young adults, with important implications for the planning of intervention treatments.

Editorial: Family History of Depression and Child Striatal Volumes in the ABCD Study: Promise and Perils of Neuroimaging Research With Large Samples

Every generation of psychopathologists is confronted with critical issues that, if left unaddressed, impede progress in both science and practice. As just one example, progress in psychiatry was hindered for many years by problems with diagnostic validity. Surmounting these problems required painstaking efforts to operationalize diagnostic criteria and to formulate effective structured interviews. More recently, critical issues facing psychiatry include tackling the so-called replication crisis, and mapping the overwhelming etiological complexity of psychopathology-two interrelated challenges. Many highly cited findings from past decades have failed to replicate, have not been subjected to replication, or have overestimated effect sizes considerably. Such findings apply to virtually all areas of psychiatric research, spanning genetics, central and peripheral biomarkers, and interventions.^1,2.

ADHD, financial distress, and suicide in adulthood: A population study

Attention-deficit/hyperactivity disorder (ADHD) exerts lifelong impairment, including difficulty sustaining employment, poor credit, and suicide risk. To date, however, studies have assessed selected samples, often via self-report. Using mental health data from the entire Swedish population (N = 11.55 million) and a random sample of credit data (N = 189,267), we provide the first study of objective financial outcomes among adults with ADHD, including associations with suicide. Controlling for psychiatric comorbidities, substance use, education, and income, those with ADHD start adulthood with normal credit demand and default rates. However, in middle age, their default rates grow exponentially, yielding poor credit scores and diminished credit access despite high demand. Sympathomimetic prescriptions are unassociated with improved financial behaviors. Last, financial distress is associated with fourfold higher risk of suicide among those with ADHD. For men but not women with ADHD who suicide, outstanding debt increases in the 3 years prior. No such pattern exists for others who suicide.

Moving beyond Ordinary Factor Analysis in Studies of Personality and Personality Disorder: A Computational Modeling Perspective

Almost all forms of psychopathology, including personality disorders, are arrived at through complex interactions among neurobiological vulnerabilities and environmental risk factors across development. Yet despite increasing recognition of etiological complexity, psychopathology research is still dominated by searches for large main effects causes. This derives in part from reliance on traditional inferential methods, including ordinary factor analysis, regression, ANCOVA, and other techniques that use statistical partialing to isolate unique effects. In principle, some of these methods can accommodate etiological complexity, yet as typically applied they are insensitive to interactive functional dependencies (modulating effects) among etiological influences. Here, we use our developmental model of antisocial and borderline traits to illustrate challenges faced when modeling complex etiological mechanisms of psychopathology. We then consider how computational models, which are rarely used in the personality disorders literature, remedy some of these challenges when combined with hierarchical Bayesian analysis.

A comparison of ICD- 11 and DSM-5 criteria for PTSD among a representative sample of Chinese earthquake survivors

BACKGROUND

Striking differences regarding the diagnosis of PTSD exist between the ICD-11 and DSM-5. This study compared the prevalence and comorbidity of PTSD between the ICD-11 and DSM-5.

METHODS

An epidemiological sample of 1160 Chinese adult earthquake survivors collected nine and a half years following the Wenchuan earthquake, in Sichuan province. The PTSD Checklist for DSM-5 (PCL-5), the Patient Health Questionnaire (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7) were used to measure PTSD, depression, and anxiety symptoms.

RESULTS

The ICD-11 PTSD criteria yielded higher prevalence estimates than the DSM-5 criteria. There were no significant differences in PTSD's comorbidity with major depressive disorder (MDD) or generalized anxiety disorder (GAD) between the ICD-11 and DSM-5 criteria.

CONCLUSIONS

Results found that the ICD-11 and DSM-5 performed differently in assessing PTSD prevalence, but showed similar co-occurrence with MDD and GAD. This study adds to knowledge about the similarities and differences of using different PTSD criteria and carries implications for clinical and research utilization of the two widely used PTSD diagnostic criteria.

RDoC and Psychopathology among Youth: Misplaced Assumptions and an Agenda for Future Research

Now over 10 years old, the Research Domain Criteria (RDoC) has gained impressive traction in the adult psychopathology literature, but enthusiasm among child and adolescent psychopathologists lags somewhat behind. We consider possible reasons why RDoC has not been embraced fully in the child and adolescent literatures. We emphasize common, interrelated, and sometimes outdated assumptions that impede scientific progress that RDoC could facilitate. Traditionally, child and adolescent psychopathologists have used behavioral syndromes as gold standards against which biological markers are validated, even though behavioral syndromes are often measured with less precision; sought to identify large main effects of single biological functions on single behavioral syndromes, thereby ignoring (even if implicitly) the overwhelming etiological complexity of psychopathology; expected 1:1 correspondencies between biological functions and behaviors, despite evidence that core biological systems subserving behavior are functionally interdependent (i.e., modulate one another); and failed to consider neurobiological mechanisms of homotypic and heterotypic comorbidity and continuity. Using examples from our work, we show how a developmental, RDoC-informed approach to externalizing behavior enriches our understanding of psychopathology. We also provide an agenda for future research, which includes calls to (1) adopt neural-systems-first approaches over disorder-first approaches when studying psychopathology, (2) eschew biological reductionism by integrating environmental risk mediators into our etiopathophysiological models, (3) integrate neural vulnerabilities into the empirical latent structure of psychopathology, and (4) replace null hypothesis significance testing with computational approaches that accommodate etiological complexity by evaluating functional dependencies among RDoC constructs, including positive valence systems (approach), negative valence systems (avoidance), and arousal/regulatory systems (self-regulation).

Irritability as a Transdiagnostic Vulnerability Trait:Current Issues and Future Directions

In recent years, irritability has received increasing attention among mental health professionals given its transdiagnostic associations with diverse forms of psychopathology. In contrast to other emotional states and traits, however, literature addressing associations between irritability and related temperament and personality constructs is limited. In addition, those who study irritability have diverse perspectives on its neurobiological substrates. In this comment, we situate irritability in the literatures on child temperament and adult personality, and describe a model in which irritability derives from low tonic dopamine (DA) levels and low phasic DA reactivity in subcortical neural structures implicated in appetitive responding. We note that different findings often emerge in neuroimaging studies when irritability is assessed in circumscribed diagnostic groups versus representative samples. We conclude with directions for future research, and propose that more authors use hierarchical Bayesian modeling, which captures functional dependencies between irritability and other dispositional traits (e.g., trait anxiety) that standard regression models are insensitive too. Treatment implications are also considered.

Impulsivity and Venturesomeness in an Adult ADHD Sample: Relation to Personality, Comorbidity, and Polygenic Risk

While impulsivity is a basic feature of attention-deficit/hyperactivity disorder (ADHD), no study explored the effect of different components of the Impulsiveness (Imp) and Venturesomeness (Vent) scale (IV7) on psychiatric comorbidities and an ADHD polygenic risk score (PRS). We used the IV7 self-report scale in an adult ADHD sample of 903 patients, 70% suffering from additional comorbid disorders, and in a subsample of 435 genotyped patients. Venturesomeness, unlike immediate Impulsivity, is not specific to ADHD. We consequently analyzed the influence of Imp and Vent also in the context of a PRS on psychiatric comorbidities of ADHD. Vent shows a distinctly different distribution of comorbidities, e.g., less anxiety and depression. PRS showed no effect on different ADHD comorbidities, but correlated with childhood hyperactivity. In a complementary analysis using principal component analysis with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition ADHD criteria, revised NEO Personality Inventory, Imp, Vent, and PRS, we identified three ADHD subtypes. These are an impulsive-neurotic type, an adventurous-hyperactive type with a stronger genetic component, and an anxious-inattentive type. Our study thus suggests the importance of adventurousness and the differential consideration of impulsivity in ADHD. The genetic risk is distributed differently between these subtypes, which underlines the importance of clinically motivated subtyping. Impulsivity subtyping might give insights into the organization of comorbid disorders in ADHD and different genetic background.

Internalizing and Externalizing Symptoms Are Associated With Different Trajectories of Cortical Development During Late Childhood

OBJECTIVE

Investigation of neurobiological differences between internalizing and externalizing symptoms in children is needed to better understand the unique pathophysiology of each, which may ultimately better target treatments and interventions. Longitudinal studies are critical, given the marked brain development that occurs in childhood; however, few such studies exist, and results are inconsistent. The aim of this study was to longitudinally investigate associations between internalizing and externalizing symptoms, and cortical thinning during late childhood.

METHOD

Participants were 105 children (49 male) from the community, who underwent magnetic resonance imaging (MRI) brain scans, and completed questionnaire measures of depressive and anxiety symptoms at two time points (mean age: 8.4 years at baseline, 10.0 years at follow-up); and, mothers, who reported on child internalizing and externalizing symptoms at both time points. Whole-brain vertex-wise regression analyses were performed to assess associations between change in cortical thickness and symptoms between baseline and follow-up.

RESULTS

Increases in internalizing symptoms over time were associated with reduced thinning in the orbitofrontal cortex, whereas increases in externalizing symptoms were associated with reduced thinning in the postcentral gyrus. The interaction between internalizing and externalizing symptom change was not associated with cortical thinning.

CONCLUSION

Results suggest that the development of internalizing and externalizing symptoms are associated with unique neurodevelopmental patterns in late childhood, potentially implicating differential deficits in affective reactivity, emotion regulation, and social cognition. Further research is required to elucidate the implications of these patterns for ongoing brain development, psychopathology, and behavior.

Excitability and irritability in preschoolers predicts later psychopathology: The importance of positive and negative emotion dysregulation

Emotion dysregulation is a risk factor for the development of a variety of psychopathologic outcomes. In children, irritability, or dysregulated negative affect, has been the primary focus, as it predicts later negative outcomes even in very young children. However, dysregulation of positive emotion is increasingly recognized as a contributor to psychopathology. Here we used an exploratory factor analysis and defined four factors of emotion dysregulation: irritability, excitability, sadness, and anhedonia, in the preschool-age psychiatric assessment collected in a sample of 302 children ages 3-5 years enriched for early onset depression. The irritability and excitability factor scores defined in preschoolers predicted later diagnosis of mood and externalizing disorders when controlling for other factor scores, social adversity, maternal history of mood disorders, and externalizing diagnoses at baseline. The preschool excitability factor score predicted emotion lability in late childhood and early adolescence when controlling for other factor scores, social adversity, and maternal history. Both excitability and irritability factor scores in preschoolers predicted global functioning into the teen years and early adolescence, respectively. These findings underscore the importance of positive, as well as negative, affect dysregulation as early as the preschool years in predicting later psychopathology, which deserves both further study and clinical consideration.

Nonsuicidal Self-Injury and Suicidal Behaviors in Girls: The Case for Targeted Prevention in Preadolescence

Non-suicidal self-injury (NSSI) affects 15-20% of adolescents-disproportionately girls-and is a strong predictor of eventual suicide attempts and suicide. Many girls now initiate NSSI before age 10. These early-starters exhibit greater frequency of NSSI, use more diverse methods, and are hospitalized more often, yet there are no empirically supported prevention programs for preadolescents. Obstacles to prevention include ascertaining who is sufficiently vulnerable and specifying mechanistic intervention targets. Recent research indicates that (1) preadolescent girls with ADHD who are also maltreated are at alarming risk for NSSI and suicide attempts by adolescence, and (2) the conjoint effects of these vulnerabilities are sufficiently potent for targeted prevention. Research also indicates that existing interventions are effective in altering child- and family-level mechanisms of NSSI. These interventions alter neurobiological markers of vulnerability, which can be used as proximal efficacy signals of prevention response, without waiting for NSSI and suicide attempts to emerge.

Reduced Reward Responsiveness Predicts Change in Depressive Symptoms in Anxious Children and Adolescents Following Treatment

Objectives: Reduced reward responsiveness, as measured by the event-related potential (ERP) component, the reward positivity (RewP), has been shown to play a role in the development of internalizing disorders, but implications for treatment remain unclear. In adult patients with anxiety and/or depression, reduced RewP has emerged as a predictor of greater change in symptoms following cognitive behavior therapy (CBT) or selective serotonin reuptake inhibitor (SSRI) treatment. The objectives of this preliminary study were to extend these findings to children and adolescents with anxiety disorders by evaluating RewP to reward as a predictor of change in anxiety severity or depressive symptoms following treatment with CBT or SSRI and to explore whether RewP differentially predicts response to one type of treatment. Methods: Patients (7-19 years old) with social and/or generalized anxiety disorder (N = 27) completed baseline measures of anxiety severity and depressive symptoms, as well as an ERP monetary reward anticipation and feedback task. RewP was measured in response to reward and breaking even feedback. Patients were then randomly assigned to CBT or SSRI treatment, and completed measures of anxiety and depressive symptom severity at the last treatment session. Results: Reduced reward responsiveness, as measured by RewP to rewards, predicted greater change in depressive symptoms following treatment, adjusting for baseline symptoms, age, and RewP to breaking even. RewP was not a significant predictor of change in anxiety symptoms. Although preliminary, exploratory analyses suggested that among anxious youth, RewP specifically predicted change in depressive symptoms following CBT, rather than SSRI. Conclusion: Results provide preliminary support for the utility of ERP measures of reward responsiveness in predicting treatment response in youth. With further research and standardization, ERP assessments could potentially be implemented in clinical settings to inform prognosis and treatment planning for youth with internalizing disorders.

Parsing neurodevelopmental features of irritability and anxiety: Replication and validation of a latent variable approach

Irritability and anxiety are two common clinical phenotypes that involve high-arousal negative affect states (anger and fear), and that frequently co-occur. Elucidating how these two forms of emotion dysregulation relate to perturbed neurodevelopment may benefit from alternate phenotyping strategies. One such strategy applies a bifactor latent variable approach that can parse shared versus unique mechanisms of these two phenotypes. Here, we aim to replicate and extend this approach and examine associations with neural structure in a large transdiagnostic sample of youth (N = 331; M = 13.57, SD = 2.69 years old; 45.92% male). FreeSurfer was used to extract cortical thickness, cortical surface area, and subcortical volume. The current findings replicated the bifactor model and demonstrate measurement invariance as a function of youth age and sex. There were no associations of youth's factor scores with cortical thickness, surface area, or subcortical volume. However, we found strong convergent and divergent validity between parent-reported irritability and anxiety factors with clinician-rated symptoms and impairment. A general negative affectivity factor was robustly associated with overall functional impairment across symptom domains. Together, these results support the utility of the bifactor model as an alternative phenotyping strategy for irritability and anxiety, which may aid in the development of targeted treatments.

The NIMH Research Domain Criteria (RDoC) Initiative and Its Implications for Research on Personality Disorder

PURPOSE OF REVIEW

We discuss the implications of the Research Domain Criteria (RDoC) initiative for neuroscience research on personality disorder (PD). To organize our review, we construct a preliminary conceptual mapping of PD symptom criteria onto RDoC constructs. We then highlight recent neuroscience research, often built around concepts that correspond to RDoC elements, and discuss the findings in reference to the constructs we consider most pertinent to PD.

RECENT FINDINGS

PD symptoms were strongly conceptually tied to RDoC constructs within the Social Processes domain, implicating brain systems involved in interpersonal rejection, facial emotion perception, and self-referential processes. Negative and Positive Valence Systems were conceptually associated with many PD symptoms, with particular relevance ascribed to the latter's Reward Valuation construct, which could reflect a more widespread disruption of computational processes involved in estimating the probability and benefits of a future outcome. Within the Cognitive Systems domain, the Cognitive Control construct mainly related to PD symptoms associated with impulse control, suggesting a connection to neural circuits that underlie goal selection and behavioral control. Arousal and Regulatory Systems could only be conceptually mapped onto PD symptoms through the Arousal construct, with different symptoms reflecting either a higher or lower biological sensitivity to internal and external stimuli. The RDoC framework has promise to advance neuroscience research on PD. The Social Processes domain is especially relevant to PD, although constructs falling within the other RDoC domains could also yield important insights into the neurobiology of PD and its connections with other forms of psychopathology. Identifying RDoC constructs (e.g., habit formation) that subserve more fundamental processes relevant to personality functioning warrants further investigation.

Differential effects of chemogenetic inhibition of dopamine and norepinephrine neurons in the mouse 5-choice serial reaction time task

Attention-deficit/hyperactivity disorder (ADHD) is a psychiatric disorder characterized by inattention, aberrant impulsivity, and hyperactivity. Although the underlying pathophysiology of ADHD remains unclear, dopamine and norepinephrine signaling originating from the ventral tegmental area (VTA) and locus coeruleus (LC) is thought to be critically involved. In this study, we employ Designer Receptor Exclusively Activated by Designer Drugs (DREADDs) together with the mouse 5-Choice Serial Reaction Time Task (5-CSRTT) to investigate the necessary roles of these catecholamines in ADHD-related behaviors, including attention, impulsivity, and motivation. By selective inhibition of tyrosine hydroxylase (TH)-positive VTA dopamine neurons expressing the Gi-coupled DREADD (hM4Di), we observed a marked impairment of effort-based motivation and subsequently speed and overall vigor of responding. At the highest clozapine N-oxide (CNO) dose tested (i.e. 2 mg/kg) to activate hM4Di, we detected a reduction in locomotor activity. DREADD-mediated inhibition of LC norepinephrine neurons reduced attentional performance in a variable stimulus duration test designed to increase task difficulty, specifically by increasing trials omissions, reducing mean score, and visual processing speed. These findings show that VTA dopamine and LC norepinephrine neurons differentially affect attention, impulsive and motivational control. In addition, this study highlights how molecular genetic probing of selective catecholamine circuits can provide valuable insights into the mechanisms underlying ADHD-relevant behaviors.

Psychiatry and developmental psychopathology: Unifying themes and future directions

In the past 35 years, developmental psychopathology has grown into a flourishing discipline that shares a scientific agenda with contemporary psychiatry. In this editorial, which introduces the special issue, we describe the history of developmental psychopathology, including core principles that bridge allied disciplines. These include (1) emphasis on interdisciplinary research, (2) elucidation of multicausal pathways to seemingly single disorders (phenocopies), (3) description of divergent multifinal outcomes from common etiological start points (pathoplasticity), and (4) research conducted across multiple levels of analysis spanning genes to environments. Next, we discuss neurodevelopmental models of psychopathology, and provide selected examples. We emphasize differential neuromaturation of subcortical and cortical neural networks and connectivity, and how both acute and protracted environmental insults can compromise neural structure and function. To date, developmental psychopathology has placed greater emphasis than psychiatry on neuromaturational models of mental illness. However, this gap is closing rapidly as advances in technology render etiopathophysiologies of psychopathology more interrogable. We end with suggestions for future interdisciplinary research, including the need to evaluate measurement invariance across development, and to construct more valid assessment methods where indicated.

Anxiety, depression, impulsivity, and brain structure in children and adolescents

The unique neuroanatomical underpinnings of internalizing symptoms and impulsivity during childhood are not well understood. In this study, we examined associations of brain structure with anxiety, depression, and impulsivity in children and adolescents. Participants were 7- to 21-year-olds (N = 328) from the Pediatric Imaging, Neurocognition, and Genetics (PING) study who completed high-resolution, 3-Tesla, T1-weighted MRI and self-report measures of anxiety, depression, and/or impulsivity. Cortical thickness and surface area were examined across cortical regions-of-interest (ROIs), and exploratory whole-brain analyses were also conducted. Gray matter volume (GMV) was examined in subcortical ROIs. When considered separately, higher depressive symptoms and impulsivity were each significantly associated with reduced cortical thickness in ventromedial PFC/medial OFC, but when considered simultaneously, only depressive symptoms remained significant. Higher impulsivity, but not depressive symptoms, was associated with reduced cortical thickness in the frontal pole, rostral middle frontal gyrus, and pars orbitalis. No differences were found for regional surface area. Higher depressive symptoms, but not impulsivity, were significantly associated with smaller hippocampal GMV and larger pallidal GMV. There were no significant associations between anxiety symptoms and brain structure. Depressive symptoms and impulsivity may be linked with cortical thinning in overlapping and distinct regions during childhood and adolescence.

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Internalizing problems and impulsivity may have shared and distinct neuroanatomical substrates in childhood.

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Higher depressive symptoms were uniquely associated with reduced cortical thickness in vmPFC/medial OFC.

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Higher impulsivity was uniquely associated with reduced cortical thickness in lateral PFC regions.

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Higher depressive symptoms were associated with smaller hippocampal volume and larger pallidal volume.

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These shared and distinct neuroanatomical correlates may inform the design of prevention and intervention strategies.

Preschool- and School-Age Irritability Predict Reward-Related Brain Function

OBJECTIVE

Although chronic irritability in childhood is prevalent, impairing, and predictive of later maladjustment, its pathophysiology is largely unknown. Deficits in reward processing are hypothesized to play a role in irritability. The current study aimed to identify how the developmental timing of irritability during preschool- and school-age relates to reward-related brain function during school-age.

METHOD

Children's irritability was assessed during the preschool period (wave 1; ages 3.0-5.9 years) and 3 years later (wave 2; ages 5.9-9.6 years) using a clinical interview. At wave 2, children (N = 46; 28 female and 18 male) performed a monetary incentive delay task in which they received rewards, if they successfully hit a target, or no reward regardless of performance, during functional magnetic resonance imaging.

RESULTS

Children with more versus less severe preschool irritability, controlling for concurrent irritability, exhibited altered reward-related connectivity: right amygdala with insula and inferior parietal lobe as well as left ventral striatum with lingual gyrus, postcentral gyrus, superior parietal lobe, and culmen. Children with more versus less severe concurrent irritability, controlling for preschool irritability, exhibited a similar pattern of altered connectivity between left and right amygdalae and superior frontal gyrus and between left ventral striatum and precuneus and culmen. Neural differences associated with irritability were most evident between reward and no-reward conditions when participants missed the target.

CONCLUSION

Preschool-age irritability and concurrent irritability were uniquely associated with aberrant patterns of reward-related connectivity, highlighting the importance of developmental timing of irritability for brain function.

Comorbidity and continuity of depression and conduct problems from elementary school to adolescence

Despite nonoverlapping criterion sets, conduct disorder and depression co-occur at much higher rates than expected by chance. Contemporary model-based approaches to explaining heterotypic comorbidity use factor analysis and its variants to evaluate interrelations among symptoms in large population-based and twin samples. These analyses invariably yield broadband internalizing and externalizing factors, which load on a higher-order general liability factor-findings that are robust across age and informant. Although model-based approaches elucidate structural aspects of comorbidity, they are variable-centered, and usually cross-sectional. Most therefore do not assess developmental continuity of comorbidity, or whether noncomorbid individuals are prospectively vulnerable to heterotypic comorbidity. We use an accelerated longitudinal design to evaluate growth in parent-reported conduct problems (CPs) and depression among children, ages 8-15 years, who were recruited at study entry into depressed only (n = 27), CPs only (n = 28), comorbid (n = 81), and control (n = 70) groups based on levels of symptoms. Consistent with normative developmental trends across this age range, steep growth in depression was exhibited by all groups, including those who reported only CPs at study entry. In contrast, growth in CPs was restricted to those who reported high symptoms at intake (with or without comorbid depression), compared with low and stable among depressed only and control participants. To our knowledge, this is the first study to demonstrate, using carefully ascertained "pure" versus comorbid groups who were followed naturalistically, that comorbid depression is likely to develop among those with pure CPs, but comorbid CPs are not likely to develop among those with pure depression. (PsycINFO Database Record

A longitudinal examination of event-related potentials sensitive to monetary reward and loss feedback from late childhood to middle adolescence

Brain regions involved in reward processing undergo developmental changes from childhood to adolescence, and alterations in reward-related brain function are thought to contribute to the development of psychopathology. Event-related potentials (ERPs), such as the reward positivity (RewP) component, are valid measures of reward responsiveness that are easily assessed across development and provide insight into temporal dynamics of reward processing. Little work has systematically examined developmental changes in ERPs sensitive to reward. In this longitudinal study of 75 youth assessed 3 times across 6years, we used principal components analyses (PCA) to differentiate ERPs sensitive to monetary reward and loss feedback in late childhood, early adolescence, and middle adolescence. We then tested reliability of, and developmental changes in, ERPs. A greater number of ERP components differentiated reward and loss feedback in late childhood compared to adolescence, but components in childhood accounted for only a small proportion of variance. A component consistent with RewP was the only one to consistently emerge at each of the 3 assessments. RewP demonstrated acceptable reliability, particularly from early to middle adolescence, though reliability estimates varied depending on scoring approach and developmental period. The magnitude of the RewP component did not significantly change across time. Results provide insight into developmental changes in the structure of ERPs sensitive to reward, and indicate that RewP is a consistently observed and relatively stable measure of reward responsiveness, particularly across adolescence.