Processing of differentially valued rewards and punishments in youths with bipolar disorder or severe mood dysregulation

Investigating the associations between irritability and hot and cool executive functioning in those with ADHD

BACKGROUND

Irritability is especially pertinent to those with Attention Deficit Hyperactivity Disorder (ADHD) as it is highly prevalent and associated with a more severe clinical presentation and poorer longitudinal outcomes. Preliminary evidence suggests that top-down cognitive processes taking place in emotional contexts (i.e., hot executive functions) as opposed to those evoked in abstract scenarios (i.e., cool executive functions) may be relevant to the presentation of irritability in ADHD. This study explored the cognitive mechanisms underlying irritability in young people with ADHD, hypothesising that irritability would be associated with hot, but not cool, executive function impairments.

METHODS

Our sample included 219 individuals with ADHD. A composite irritability score was derived extracting items from a parent interview, with scores ranging from 0 to 5. Associations were investigated using linear regression analyses, between irritability and four hot tasks measuring sensitivity to risk, risk-taking behaviour following reward or punishment, acceptance of reward delay and reaction to unfair behaviour from others, and two cool tasks measuring set-shifting and motor inhibition.

RESULTS

As hypothesised, there were no significant associations between irritability and cool executive functions in those with ADHD; however, contrary to expectations, there was also no significant evidence that hot executive functions were associated with irritability.

CONCLUSIONS

These results, in a large well characterised sample and using a comprehensive task battery, suggest that the variation in irritability in those with ADHD may not be associated with differences in hot or cool executive function performance.

Underlying mechanisms of disruptive mood dysregulation disorder in children: A systematic review by means of research domain criteria

Background

A systematic overview of underlying mechanisms in the new disruptive mood dysregulation disorder (DMDD) diagnosis is needed. The Research Domain Criteria (RDoC) represent a system of six domains of human functioning, which aims to structure the understanding of the nature of mental illnesses. By means of the RDoC framework, the objective of this systematic review is to synthesize available data on children and youths <18 years suffering from DMDD as reported in peer reviewed papers.

Methods

A literature search guided by PRISMA was conducted using Medline, PsychInfo, and Embase, while the RDoC domains were employed to systematize research findings. Risk of bias in the included studies was examined.

Results

We identified 319 studies. After study selection, we included 29 studies. Twenty-one of these had findings relating to >1 RDoC domain. The risk of bias assessment shows limitations in the research foundation of current knowledge on mechanisms of DMDD.

Discussion

Reviewing self-report, behavior and neurocircuit findings by means of RDoC domains, we suggest that DMDD youths have a negative interpretation bias in social processes and valence systems. In occurrence of a negative stimuli interpretation, aberrant cognitive processing may arise. However, current knowledge of DMDD is influenced by lack of sample diversity and open science practices.

Conclusion

We found the six RDoC domains useful in structuring current evidence of the underlying mechanisms of DMDD. Important opportunities for future studies in this field of research are suggested. In clinical practice, this comprehensive summary on DMDD mechanisms can be used in psychoeducation and treatment plans.

Psychiatric Neural Networks and Precision Therapeutics by Machine Learning

Learning and environmental adaptation increase the likelihood of survival and improve the quality of life. However, it is often difficult to judge optimal behaviors in real life due to highly complex social dynamics and environment. Consequentially, many different brain regions and neuronal circuits are involved in decision-making. Many neurobiological studies on decision-making show that behaviors are chosen through coordination among multiple neural network systems, each implementing a distinct set of computational algorithms. Although these processes are commonly abnormal in neurological and psychiatric disorders, the underlying causes remain incompletely elucidated. Machine learning approaches with multidimensional data sets have the potential to not only pathologically redefine mental illnesses but also better improve therapeutic outcomes than DSM/ICD diagnoses. Furthermore, measurable endophenotypes could allow for early disease detection, prognosis, and optimal treatment regime for individuals. In this review, decision-making in real life and psychiatric disorders and the applications of machine learning in brain imaging studies on psychiatric disorders are summarized, and considerations for the future clinical translation are outlined. This review also aims to introduce clinicians, scientists, and engineers to the opportunities and challenges in bringing artificial intelligence into psychiatric practice.

Traits of empathy and anger: implications for psychopathy and other disorders associated with aggression

Empathy and anger are two social emotions that modulate an individual's risk for aggression. Empathy is an emotional reaction to another individual's emotional state. Anger is an emotional reaction to threat, frustration or social provocation. Reduced empathy, seen in psychopathy, increases the risk for goal-directed aggression. Atypically increased anger (i.e. irritability), seen in conditions like disruptive mood dysregulation disorder and borderline personality disorder, increases the risk for reactive aggression. In this paper, I will outline core neurocognitive functions that correspond to empathy and which are compromised in individuals with psychopathic traits. In addition, I will outline neurocognitive functions involved in either the generation or regulation of anger and which are compromised in psychiatric conditions at increased risk for irritability/reactive aggression. It can be hoped that improved understanding of empathy and anger will lead to better assessment tools and improved interventions to reduce aggression risk.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

Probabilistic reinforcement learning abnormalities and their correlates in adolescent bipolar disorders

Theoretical models of bipolar disorders (BD) posit core deficits in reward system function. However, specifying which among the multiple reward system's neurobehavioral processes are abnormal in BD is necessary to develop appropriately targeted interventions. Research on probabilistic-reinforcement learning deficits in BD is limited, particularly during adolescence, a period of significant neurodevelopmental changes in the reward system. The present study investigated probabilistic-reinforcement learning, using a probabilistic selection task (PST), and its correlates, using self-reported reward/threat sensitivities and cognitive tasks, in 104 adolescents with and without BD. Compared with healthy peers, adolescents with BD were less likely to persist with their choices based on prior positive feedback (i.e., lower win-stay rates) in the PST's acquisition phase. Across groups, a greater win-stay rate appeared to be a more efficient learning strategy-associated with fewer acquisition trials and better testing phase performance. Win-stay rates were also related to verbal learning indices, but not self-reported reward/threat sensitivities. Finally, lower win-stay rates had significant incremental validity in predicting a BD diagnosis, after accounting for effects of current symptoms, reward sensitivities, verbal learning, and IQ. The present findings support multiple dysfunctional processes of the reward system in adolescent BD that require additional examinations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Disruptive Mood Dysregulation Disorder (DMDD): An RDoC perspective

In recent years, there has been much debate regarding the most appropriate diagnostic classification of children exhibiting emotion dysregulation in the form of irritability and severe temper outbursts. Most recently, this has resulted in the addition of a new diagnosis, Disruptive Mood Dysregulation Disorder (DMDD) in the DSM 5. The impetus for including this new disorder was to reduce the number of diagnoses that these children would typically receive; however, there is concern that it has only complicated matters rather than simplifying them. For example, a recent epidemiologic study shows that DMDD cannot be differentiated from oppositional defiant disorder (ODD) based on symptoms alone. Thus, these children are an ideal population in which to apply RDoC constructs in order to obtain greater clarity in terms of underlying processes and ultimately, inform nosology and appropriate interventions. The aim of this article is to provide a foundation for future research by examining extant theoretical and empirical evidence for the role of four key RDoC constructs in DMDD.

Explicit and implicit reinforcement learning across the psychosis spectrum

Motivational and hedonic impairments are core features of a variety of types of psychopathology. An important aspect of motivational function is reinforcement learning (RL), including implicit (i.e., outside of conscious awareness) and explicit (i.e., including explicit representations about potential reward associations) learning, as well as both positive reinforcement (learning about actions that lead to reward) and punishment (learning to avoid actions that lead to loss). Here we present data from paradigms designed to assess both positive and negative components of both implicit and explicit RL, examine performance on each of these tasks among individuals with schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis, and examine their relative relationships to specific symptom domains transdiagnostically. None of the diagnostic groups differed significantly from controls on the implicit RL tasks in either bias toward a rewarded response or bias away from a punished response. However, on the explicit RL task, both the individuals with schizophrenia and schizoaffective disorder performed significantly worse than controls, but the individuals with bipolar did not. Worse performance on the explicit RL task, but not the implicit RL task, was related to worse motivation and pleasure symptoms across all diagnostic categories. Performance on explicit RL, but not implicit RL, was related to working memory, which accounted for some of the diagnostic group differences. However, working memory did not account for the relationship of explicit RL to motivation and pleasure symptoms. These findings suggest transdiagnostic relationships across the spectrum of psychotic disorders between motivation and pleasure impairments and explicit RL. (PsycINFO Database Record

Irritability in child and adolescent psychopathology: An integrative review for ICD-11

In preparation for the World Health Organization's development of the Eleventh Revision of the International Classification of Diseases and Related Health Problems (ICD-11) chapter on Mental and Behavioral Disorders, this article reviews the literature pertaining to severe irritability in child and adolescent psychopathology. First, research on severe mood dysregulation suggests that youth with irritability and temper outbursts, among other features of hyperactivity and arousal, demonstrate cross-sectional correlates and developmental outcomes that distinguish them from youth with bipolar disorder. Second, other evidence points to an irritable dimension of Oppositional Defiant Disorder symptomatology, which is uniquely associated with concurrent and subsequent internalizing problems. In contrast to the Diagnostic and Statistical Manual of Mental Disorders' (5th ed.) Disruptive Mood Dysregulation Disorder, our review of the literature supports a different solution: a subtype, Oppositional Defiant Disorder with chronic irritability/anger (proposal included in Appendix). This solution is more consistent with the available evidence and is a better fit with global public health considerations such as harm/benefit potential, clinical utility, and cross-cultural applicability. Implications for assessment, treatment, and research are discussed.

Associations of age with reward delay discounting and response inhibition in adolescents with bipolar disorders

OBJECTIVES

Bipolar disorders' (BD) onset before age 18 is a potential marker for a more severe illness course. Adolescence is also a period of significant normative maturation of inhibitory control and reward-relevant decision-making processes, such as decreased delay discounting (i.e., decreased preference for smaller, immediate versus larger, delayed rewards). Adults with BD exhibit elevated delay discounting rates. Very little is known about developmental changes in delay discounting in adolescents with BD, or about associations between inhibitory control and delay discounting in BD. The present study addresses these questions.

METHODS

The sample included 78 participants, ages 13 to 23, with BD or without history of mental illness. Group differences and group by age interaction effects on delay discounting (32 BD, 32 controls with valid responses), probability discounting (34 BD, 37 controls) and inhibitory control indices (34 BD, 38 controls) were assessed.

RESULTS

Among healthy controls, less discounting of delayed rewards was associated with older age, whereas adolescents with BD did not show age-related associations. There were no group differences in probability discounting or inhibitory control.

LIMITATIONS

The cross-sectional nature of the study cannot fully rule out the less likely interpretation of group differences in cohort effects.

CONCLUSIONS

The lack of age-related improvement in delay tolerance in BD suggests disrupted development of executive control processes within reward contexts, which in turn may contribute to understanding more severe course of pediatric onset BD. Longitudinal studies are needed to examine delay discounting in relation to maturation of neural reward systems among adolescents with BD.

Comorbidity in pediatric bipolar disorder: prevalence, clinical impact, etiology and treatment

BACKGROUND

Research on pediatric bipolar disorder (PBD) is providing a plethora of empirical findings regarding its comorbidity. We addressed this question through a systematic review concerning the prevalence, clinical impact, etiology and treatment of main comorbid disorders involved.

METHOD

A comprehensive database search was performed from 1990 to August 2014. Overall, 167 studies fulfilled the inclusion criteria.

RESULTS

Bipolar youth tend to suffer from comorbid disorders, with highest weighted mean prevalence rate arising from anxiety disorders (54%), followed by attention deficit hyperactivity disorder (ADHD) (48%), disruptive behavior disorders (31%), and substance use disorders (SUD) (31%). Furthermore, evidence indicates that ADHD and anxiety disorders negatively affect the symptomatology, neurocognitive profile, clinical course and the global functioning of PBD. Likewise, several theories have been posited to explain comorbidity rates in PBD, specifically common risk factors, one disorder being a risk factor for the other and nosological artefacts. Lastly, randomized controlled trials highlight a stronger therapeutic response to stimulants and atomoxetine (vs. placebo) as adjunctive interventions for comorbid ADHD symptoms. In addition, research focused on the treatment of other comorbid disorders postulates some benefits from mood stabilizers and/or SGA.

LIMITATIONS

Epidemiologic follow-up studies are needed to avoid the risk of nosological artefacts. Likewise, more research is needed on pervasive developmental disorders and anxiety disorders, especially regarding their etiology and treatment.

CONCLUSIONS

Psychiatric comorbidity is highly prevalent and is associated with a deleterious clinical effect on pediatric bipolarity. Different etiological pathways may explain the presence of these comorbid disorders among bipolar youth. Standardized treatments are providing ongoing data regarding their effectiveness for these comorbidities among bipolar youth.

Neurocognitive impairments among youth with pediatric bipolar disorder: a systematic review of neuropsychological research

BACKGROUND

Pediatric bipolar disorder (PBD) has emerged as a field of research in which neuropsychological studies are continuously providing new empirical findings. Despite this, a comprehensive framework for neurocognitive impairments is still lacking, and most of the evidence remains unconnected. We addressed this question through a systematic review of neuropsychological research, with the aim of elucidating the main issues concerning this topic.

METHOD

A comprehensive search of databases (PubMed, PsycINFO) was performed. Published manuscripts between 1990 and January 2014 were identified. Overall, 124 studies fulfilled inclusion criteria. Methodological differences between studies required a descriptive review of findings.

RESULTS

Evidence indicates that verbal/visual-spatial memory, processing speed, working memory, and social cognition are neurocognitive domains impaired in PBD youth. Furthermore, these deficits are greater among those who suffer acute affective symptoms, PBD type I, and/or attention deficit hyperactivity disorder (ADHD) comorbidity. In addition, several neurocognitive deficits imply certain changes in prefrontal cortex activity and are somewhat associated with psychosocial and academic disabilities. Strikingly, these deficits are consistently similar to those encountered in ADHD as well as severe mood dysregulation (SMD). Besides, some neurocognitive impairments appear before the onset of the illness and tend to maintain stable across adolescence. Finally, any therapy has not yet demonstrated to be effective on diminishing these neurocognitive impairments.

LIMITATIONS

More prolonged follow-up studies aimed at delineating the course of treatment and the response to it are warranted.

CONCLUSIONS

Despite noteworthy research on the neurocognitive profile of PBD, our knowledge is still lagging behind evidence from adult counterparts.

Irritability in children and adolescents: past concepts, current debates, and future opportunities

Irritability is defined as a low threshold to experience anger in response to frustration. It is one of the most common symptoms in youth and is part of the clinical presentation of several disorders. Irritability can present early in life and is a predictor of long-term psychopathology; yet, the diagnostic status of irritability is a matter of intense debate. In the present article, we address two main components of the debate regarding irritability in youth: the misdiagnosis of chronic irritability as pediatric bipolar disorder, and the proposal of a new diagnosis in the DSM-5, disruptive mood dysregulation disorder, whose defining symptoms are chronic irritability and temper outbursts.

Reward dysregulation and mood symptoms in an adolescent outpatient sample

Research on bipolar spectrum disorders (BPSD) in adolescence has burgeoned in the last decade, but continued work is needed to identify endophenotypic markers associated with illness onset and course. The present study examined reward dysregulation--measured via the behavioral activation system (BAS)--as one putative marker of BPSD in adolescence. A diverse group of 425 outpatient adolescents between 11 and 17 years of age (52 % male) completed the Behavioral Inhibition and Activation Scale (BIS-BAS) scale to measure reward dysregulation. Semi-structured interviews determined diagnoses and severity of mood symptoms. Parent-reported BAS was associated with increased symptoms of mania, and parent and adolescent-reported BAS were associated with symptoms of depression. Parent-reported BIS scores were associated with increased symptoms of mania. Results held independent of diagnostic status. Furthermore, parent BIS/BAS reports were stronger predictors for manic symptoms compared to adolescent-reports. Results extend work in adults with BPSD, suggesting a transdiagnostic association between reward dysregulation and mood symptom severity in adolescence.

The neglected role of positive emotion in adolescent psychopathology

Adolescence is a developmental period characterized by elevated stress, heightened risky behaviors, and increases in psychopathology. Emotion dysregulation is a hypothesized contributor to negative outcomes and to the onset of psychopathology during adolescence. However, the dysregulation of negative emotion has been the focus of research while the literature on positive emotion in adolescent psychopathology is limited. This review highlights both the development of normative and dysregulated positive emotion during adolescence. First, the literature on normative adolescent emotional development and on negative emotional regulation is briefly reviewed, followed by a discussion of current theories of positive emotion, which are grounded in the adult literature. From a developmental perspective, the dimension of approach motivation within positive emotion is emphasized throughout and frames the review. This conceptualization guides organization of literatures on normative experiences of positive emotion in adolescence and the role of dysregulated positive emotion in adolescent psychopathology, specifically adolescent depression, anxiety, bipolar disorder, externalizing disorders and eating disorders. Last, future directions in the study of adolescent positive emotion and its regulation and the implications of highlighting approach motivation in normative and dysregulated positive emotion in adolescence are detailed.

Brain functional domains inform therapeutic interventions in attention-deficit/hyperactivity disorder and pediatric bipolar disorder

A deeper understanding of how the relationships between impulsivity, reward systems and executive function deficits may be similar or different in attention-deficit/hyperactivity disorder (ADHD) and pediatric bipolar disorder (PBD) is fundamental for better defining phenotypy in these two developmental illnesses, and moving towards improved treatment and intervention. We focus our article on recent neurocognitive and neuroimaging data examining the behavioral and neural aspects of poor behavior regulation, response inhibition and reward systems in ADHD and PBD. In light of recent research evidence, we propose that the common behavioral manifestations of impulsivity in ADHD and PBD may indeed originate from different neural mechanisms mediated by altered reward systems. In order to define and differentiate these mechanisms, unlike previous approaches, our theoretical model examines the interface of the dorsal frontostriatal circuit, involved in behavior regulation, and the ventral frontostriatal circuit, which is involved in reward-related and affect processes. Preliminary evidence suggests that the neural systems involved in impulsivity, reward systems and executive function engage differently in the two illnesses. In PBD, 'emotional impulsivity' is predominantly 'bottom-up' and emotionally/motivationally driven, and stems from ventral frontostriatal circuitry dysfunction. By contrast, in ADHD 'cognitive impulsivity' is predominantly 'top-down' and more 'cognitively driven', and stems from dorsal frontostriatal dysfunction. We discuss this evidence in view of clinically relevant questions and implications for illness-based intervention. We conclude that the reward-related mechanisms underlying the interactions between executive function, behavior regulation and impulsivity in PBD and ADHD may be differentially compromised, and in accordance differently shape the clinical symptoms of impulsivity and goal-directed behavior.

Neurocognitive performance in children and adolescents with bipolar disorder: a review

A number of studies have reported the evidence of cognitive deficits in adult bipolar patients. Recently, there has been a shift in research on neurocognitive performance in bipolar disorder (BD) towards examining younger age groups. A review of the literature on neurocognitive impairments in BD in childhood and adolescence was conducted. We searched systematically for studies in samples of age groups younger than 18 years of age in average that included either a healthy control group or normative data for the cognitive tests used. Twenty-one original articles were found and reviewed. Children and adolescents with BD show deficits in a variety of cognitive areas. The most consistent results were found for impairments in verbal memory. A majority of studies also indicated impairments in working memory. Similar pattern of neurocognitive impairment was found in children and adolescents as compared to adults suffering from BD. The neurocognitive deficits need to be recognized and incorporated into individual treatment programs.

An open-label trial of risperidone in children and adolescents with severe mood dysregulation

OBJECTIVE

The diagnosis and treatment of youth with severe nonepisodic irritability and hyperarousal, a syndrome defined as severe mood dysregulation (SMD), has been the focus of increasing concern and debate among clinicians and researchers. Our main objective was to assess the effectiveness of risperidone for youths with SMD.

METHODS

An 8-week open label trial with risperidone was conducted. We extensively assessed 97 subjects with semistructured and clinical interviews and enrolled 21 patients in the study. Risperidone was titrated from 0.5 to 3 mg/day in the first 2 weeks. Evaluations were performed at baseline and weeks 2, 4, 6, and 8. Clinical outcome measures were (1) Aberrant Behavior Checklist-Irritability Subscale, (2) Clinical Global Impressions, and (3) severity of co-morbid conditions.

RESULTS

We found a significant reduction of the Aberrant Behavior Checklist-Irritability scores during the trial after risperidone use (p < 0.001). The scores at week 2 (mean = 12.03; standard error [SE] = 2.94), week 4 (mean = 15.48; SE = 2.93), week 6 (mean = 12.29; SE = 2.86), and week 8 (mean = 11.28; SE = 3.06) were significantly reduced compared with the baseline mean score (mean = 25.89; SE = 2.76) (p < 0.001). We also found an improvement in attention-deficit/hyperactivity disorder, depression, and global functioning (p < 0.001).

CONCLUSION

Risperidone was effective in reducing irritability in SMD youth. To the best of our knowledge, this is the first psychopharmacological trial in this group of patients with positive results. Further randomized, controlled studies are needed.

Perturbed reward processing in pediatric bipolar disorder: an antisaccade study

Pediatric bipolar disorder is a severe and impairing illness. Characterizing the impact of pediatric bipolar disorder on cognitive function might aid in understanding the phenomenology of the disorder. While previous studies of pediatric bipolar disorder have reported deficits in cognitive control and reward behavior, little is understood about how affective processes influence behavioral control. Relative to prior studies using manual-response paradigms, eye movement tasks provide a more precise assessment of reward sensitivity and cognitive and motor control. The current study compares 20 youths with bipolar disorder (mean age = 13.9 years ± 2.22) and 23 healthy subjects (mean age = 13.8 years ± 2.49) on a mixed pro-antisaccade task with monetary incentives. On both types of saccades, participants were presented with three types of incentives: those where subjects can win money, lose money, or neither win nor lose money. Impaired reward processing was found in youths with bipolar disorder relative to controls, particularly on antisaccades. This difference was reflected in lower error rates during incentive trials in the control but not in the bipolar disorder group. By comparison, no group differences were found on prosaccade trials. The results provide further evidence for deficits in cognitive and reward processing in bipolar disorder.

Affect regulation in pediatric bipolar disorder

Increasingly, clinicians and researchers alike are describing children presenting with emotional and behavioral problems as suffering from deficits of "affect regulation." The present article reviews the current understanding of affect regulation. The authors also discuss recent findings implicating affect dysregulation in children and adolescents with bipolar disorder.