A Population-Based Twin Study of Childhood Irritability and Internalizing Syndromes

An Expanded Conceptual Framework for Understanding Irritability in Childhood: The Role of Cognitive Control Processes

Children prone to irritability experience significant functional impairments and internalising and externalising problems. Contemporary models have sought to elucidate the underlying mechanisms in irritability, such as aberrant threat and reward biases to improve interventions. However, the cognitive control processes that underlie threat (e.g., attention towards threats) and reward (e.g., attention towards reward-related cues) biases and the factors which influence the differential activation of positive and negative valence systems and thus leading to maladaptive activation of cognitive control processes (i.e., proactive and reactive control) are unclear. Thus, we aim to integrate extant theoretical and empirical research to elucidate the cognitive control processes underlying threat and reward processing that contribute to irritability in middle childhood and provide a guiding framework for future research and treatment. We propose an expanded conceptual framework of irritability that includes broad intraindividual and environmental vulnerability factors and propose proximal 'setting' factors that activate the negative valence and positive valence systems and proactive and reactive cognitive control processes which underpin the expression and progression of irritability. We consider the implications of this expanded conceptualisation of irritability and provide suggestions for future research.

Systematic Review and Meta-Analysis: Early Irritability as a Transdiagnostic Neurodevelopmental Vulnerability to Later Mental Health Problems

OBJECTIVE

Irritability is a transdiagnostic indicator of child and adolescent internalizing and externalizing problems that is measurable from early life. The objective of this systematic review was to determine the strength of the association between irritability measured from 0 to 5 years and later internalizing and externalizing problems, to identify mediators and moderators of these relationships, and to explore whether the strength of the association varied according to irritability operationalization.

METHOD

Relevant studies published in peer-reviewed, English-language journals between the years 2000 and 2021 were sought from EMBASE, PsycINFO, MEDLINE, CINAHL, and ERIC. We synthesized studies that included a measure of irritability within the first 5 years of life and reported associations with later internalizing and/or externalizing problems. Methodological quality was assessed using the JBI-SUMARI Critical Appraisal Checklist.

RESULTS

Of 29,818 identified studies, 98 met inclusion criteria, with a total number of 932,229 participants. Meta-analysis was conducted on 70 studies (n = 831,913). Small, pooled associations were observed between infant irritability (0-12 months) and later internalizing (r = 0.14, 95% CI = 0.09, 0.20) and externalizing symptoms (r = 0.16, 95% CI = 0.11, 0.21) symptoms. For toddler/preschool irritability (13-60 months), small-to-moderate pooled associations were observed for internalizing (r = 0.21, 95% CI = 0.14, 0.28) and externalizing (r = 0.24, 95% CI = 0.18, 0.29) symptoms. These associations were not moderated by the lag between irritability and outcome assessment, although the strength of the associations varied according to irritability operationalization.

CONCLUSION

Early irritability is a consistent transdiagnostic predictor of internalizing and externalizing symptoms in childhood and adolescence. More work is required to understand how to accurately characterize irritability across this developmental period, and to understand mechanisms underlying the relationship between early irritability and later mental health problems.

DIVERSITY & INCLUSION STATEMENT

One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. One or more of the authors of this paper self-identifies as living with a disability. We actively worked to promote sex and gender balance in our author group. We actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our author group.

STUDY PREREGISTRATION INFORMATION

Early irritability as a transdiagnostic neurodevelopmental vulnerability to early onset mental health problems: A systematic review; https://www.crd.york.ac.uk/prospero/; CRD42020214658.

The Impact of Irritability and Callous Unemotional Traits on Reward Positivity in Youth with ADHD and Conduct Problems

Children with attention-deficit/hyperactivity disorder (ADHD) and conduct problems exhibit significant variability in functioning and treatment response that cannot be fully accounted for by differences in symptom severity. Reward responsivity (RR) is a potential transdiagnostic means to account for this variability. Irritability and callous-unemotional (CU) traits moderate associations between both ADHD and conduct problems with multiple realms of functioning. Both are theorized to be associated with RR, but associations in clinical samples are unknown. In 48 youth ages 5-12 with ADHD referred for treatment of conduct problems, we examined RR using a guessing task where participants select a door icon to win and lose money. Analyses focused on the reward positivity (RewP) event-related potential in response to gain and loss feedback, which reliably peaks approximately 300 ms after feedback. Frequentist and Bayesian approaches assessed main effects of ADHD, Conduct Disorder (CD) and non-irritable Oppositional Defiant Disorder (ODD) symptoms with RR, plus interactions between symptoms and affective dimensions (irritability, CU). CD and ODD were hypothesized to be associated with altered RR, with irritability and CU moderating these associations. Across models, a reliable CD x irritability interaction emerged, indicating enhanced RewP when irritability was elevated and CD symptoms were low. CU did not moderate any associations with RR, and little support was found for associations between RR and other symptom domains. As neural response to reward varied with levels of irritability and CD symptoms, RR may hold potential as a clinically-relevant biomarker in youth with ADHD and conduct problems.

Psychological and social risk factors associated with development of psychopathology, controlling for biological influence

PURPOSE OF REVIEW

To evaluate and summarize recent research investigating psychological, social and environmental risk factors for development of psychopathology in childhood, while controlling for biological (genetic) influences by using a matched sibling, twin or adoptee design.

RECENT FINDINGS

Nineteen studies were included, of which eleven were longitudinal and eight were cohort studies. Included studies used adequate designs and statistical methods, controlled for unmeasured confounders and, in many cases, for other measured risk factors. None of the studies used the framework for environmental factors presented in the International Classification of Functioning, Disability and Health (ICF). The outcome variable psychopathology was rarely assessed using a diagnostic standard. The findings were sorted in five themes based on included exposures: 'Social support, social rejection and perceived identity,' 'Early symptoms of psychopathology,' 'Antibiotic exposure,' 'Factors in the family' and 'Nature versus nurture'.

SUMMARY

Using twin/sibling/adoptee designs, a number of unique predictors of psychopathology were found, even when controlling for familial confounders and other specified risk factors. Future studies of psychopathology development should benefit from longitudinal, genetically sensitive designs and from use of diagnostic standards for psychopathology outcome, and should also incorporate ICF for classification of risk factors.

Pediatric anxiety associated with altered facial emotion recognition

Multiple psychiatric disorders are associated with difficulties in facial emotion recognition. However, generalized anxiety disorder may be associated with more accurate recognition of others' emotional expressions, particularly expressions of happiness and fear, which index safety and threat. Children aged 9-14 from a community sample (N = 601) completed a facial emotion labeling task. Children's symptoms of depressive and anxiety syndromes were assessed by self- and parent-report. Elevated symptoms of generalized anxiety disorder were associated with more accurate facial emotion recognition (β = 0.16, p = 0.007), specifically recognition of happiness (β = 0.17, p = 0.002) and fear (β = 0.15, p = 0.006). Elevated depressive symptoms were associated with less accurate facial emotion recognition (β = -0.12, p = 0.018), specifically happiness (β = -0.15, p = 0.002). Elevated symptoms of separation anxiety disorder were also associated with less accurate facial emotion recognition (β = -0.16, p = 0.003), specifically happiness (β = -0.15, p = 0.006) and fear (β = -0.15, p = 0.005), which highlights the importance of distinguishing between anxiety syndromes. Results held when adjusting for child age and sex. Evidence that symptoms of generalized anxiety disorder are associated with more accurate recognition of happiness and fear is consistent with theories of heightened social vigilance and support a transdiagnostic role of facial emotion recognition that may inform the psychosocial development of youth with anxiety and depressive symptoms.

Preventing Irritability and Temper Outbursts in Youth by Building Resilience

Severe irritability and temper outbursts are risk factors for the onset of serious and lifelong mood disorders. In treating children and adolescents with severe irritability, clinicians should evaluate and address safety issues before acute stabilization of symptoms. Then, clinicians can initiate interventions to prevent the onset or relapses of the undesired behavior and its functional consequences. This review summarizes primary, secondary, and tertiary relapse prevention strategies, with an emphasis on strategies that build resilience in youth that mitigate the onset, recurrence, and progression of emotion dysregulation.

How and Why Are Irritability and Depression Linked?

Based on its course over time, irritability is linked to depression cross-sectionally and longitudinally. Cross-sectionally, irritability takes an episodic form as a symptom in pediatric depression; yet, irritability in the absence of depressed mood or anhedonia is rare. Longitudinally, chronic irritability has been shown to predict depression rather than bipolar disorder or externalizing disorders. Evidence suggests that the link between irritability and depression is explained mostly by shared genetic risk. Both conditions are also associated with higher rates of family history of depression, childhood temperaments and personality styles, and negative parenting styles. The treatment implications are discussed.

Attention Problems and Restlessness as Transdiagnostic Markers of Severity and Treatment Response in Youth with Internalizing Problems

Transdiagnostic models of psychopathology suggest that disorders may share common features that could influence their severity. Attention problems and psychomotor restlessness are included in the diagnostic criteria for several disorders, including disorders on the internalizing spectrum, but their transdiagnostic significance has received little attention. The present study identifies patterns of attention problems and restlessness among youth with internalizing problems, in order to understand their clinical significance in terms of internalizing symptom severity and response to cognitive behavioral therapy (CBT). Participants were 142 adolescents age 11-18 clinically referred for mood and/or anxiety problems. Latent class analysis was used to identify patterns of self-reported attention problems and psychomotor restlessness, and classes were compared on internalizing, depression, and anxiety severity. Differences in treatment response were examined in a subset of youth (n = 82; age 14-18) who participated in group CBT. Youth in the Attention Problems class (42% of sample) and youth in the Restless class (15% of sample) endorsed significantly more internalizing, depression, and anxiety problems than youth with Low Symptoms of attention problems or psychomotor restlessness (43% of sample). Youth in the Restless class responded significantly better to CBT than youth in the Low Symptoms of attention problems or psychomotor restlessness class in terms of decrease in overall internalizing problems. Attention problems and psychomotor restlessness appear to be important transdiagnostic markers of severity across the internalizing spectrum; however, they do not limit the effectiveness of CBT and, in the case of psychomotor restlessness, may forecast a good treatment response.