Assessing Irritability in Children with Autism Spectrum Disorder Using the Affective Reactivity Index

Intranasal Oxytocin in Pediatric Populations: Exploring the Potential for Reducing Irritability and Modulating Neural Responses: A Mini Review

Endogenous neuropeptide Oxytocin (OXT) plays a crucial role in modulating pro-social behavior and the neural response to social/emotional stimuli. Intranasal administration is the most common method of delivering OXT. Intranasal OXT has been implemented in clinical studies of various psychiatric disorders with mixed results, mainly related to lack of solid pharmacodynamics and pharmacokinetics model. Due to intranasal OXT's mechanism of reducing the activation of neural areas implicated in emotional responding and emotion regulation, a psychopathology with this target mechanism could be potentially excellent candidate for future clinical trial. In this regard, irritability in youth may be a very promising target for clinical studies of intranasal OXT. Here we provide a mini-review of fifteen randomized controlled trials in pediatric patients with diagnoses of autism spectrum disorder (ASD), Prader-Willi syndrome (PWS), or Phelan-McDermid syndrome (PMS). Most studies had small sample sizes and varying dosages, with changes in irritability, mainly as adverse events (AEs). Neuroimaging results showed modulation of the reward processing system and the neural areas implicated in social-emotional information processing by intranasal OXT administration. Further research is needed to determine the most effective dose and duration of OXT treatment, carefully select target psychopathologies, verify target engagement, and measure adverse event profiles.

Autistic Symptoms, Irritability, and Executive Dysfunctions: Symptom Dynamics from Multi-Network Models

Socio-cognitive difficulties in individuals with autism spectrum disorder (ASD) are heterogenuous and often co-occur with irritability symptoms, such as angry/grouchy mood and temper outbursts. However, the specific relations between individual symptoms are not well-represented in conventional methods analyzing aggregated autistic symptoms and ASD diagnosis. Moreover, the cognitive-behavioral mechanisms linking ASD to irritability are largely unknown. This study investigated the dynamics between autistic (Social Responsiveness Scale) and irritability (Affective Reactivity Index) symptoms and executive functions (Cambridge Neuropsychological Test Automated Battery) in a sample of children and adolescents with ASD, their unaffected siblings, and neurotypical peers (N = 345, aged 6-18 years, 78.6% male). Three complementary networks across the entire sample were computed: (1) Gaussian graphical network estimating the conditional correlations between symptom nodes; (2) Relative importance network computing relative influence between symptoms; (3) Bayesian directed acyclic graph estimating predictive directionality between symptoms. Networks revealed numerous partial correlations within autistic (rs = .07-.56) and irritability (rs = .01-.45) symptoms and executive functions (rs = -.83 to .67) but weak connections between clusters. This segregated pattern converged in all directed and supplementary networks. Plausible predictive paths were found between social communication difficulties to autism mannerisms and between "angry frequently" to "lose temper easily." Autistic and irritability symptoms are two relatively independent families of symptoms. It is unlikely that executive dysfunctions explain elevated irritability in ASD. Findings underscore the need for researching other mood and cognitive-behavioral bridge symptoms, which may inform individualized treatments for co-occurring irritability in ASD.

Measuring Irritability in Early Childhood: A Psychometric Evaluation of the Affective Reactivity Index in a Clinical Sample of 3- to 8-Year-Old Children

The parent-report Affective Reactivity Index (ARI-P) is the most studied brief scale specifically developed to assess irritability, but relatively little is known about its performance in early childhood (i.e., ≤8 years). Support in such populations is particularly important given developmental shifts in what constitutes normative irritability across childhood. We examined the performance of the ARI-P in a diverse, treatment-seeking sample of children ages 3 to 8 years (N = 115; mean age = 5.56 years; 58.4% from ethnic/racial minority backgrounds). In this sample, confirmatory factor analysis supported the single-factor structure of the ARI-P previously identified with older youth. ARI-P scores showed large associations with another irritability index, as well as small-to-large associations with aggression, anxiety, depression, and attention problems, supporting the convergent and concurrent validity of the ARI-P when used with children in this younger age range. Findings support the ARI-P as a promising parent-report tool for assessing irritability in early childhood, particularly in clinical samples.

Measurement and correlates of irritability in clinically referred youth: Further examination of the Affective Reactivity Index

BACKGROUND

Research on youth irritability has proliferated in recent years, largely facilitated by items from existing measures and by key new instruments like the Affective Reactivity Index (ARI). The present study extends this literature by investigating the psychometric properties of the parent- and youth-report ARI and the correlates of irritability in an independent, clinically referred sample.

METHOD

Baseline assessment data were collected from 237 youths (ages 3-18; 36% female) and their parents, seen for outpatient therapy and/or assessment. We examined the ARI in terms of (1) its item, scale, and factor properties; (2) convergent/discriminant validity with internalizing, externalizing, and emotion regulation problems; (3) specificity of associations with reactive aggression, anger, dysregulation, and coping; and (4) robustness of associations after controlling for demographic variables (e.g., age, gender).

RESULTS

The ARI's internal consistency and unidimensional factor structure were acceptable or better, with some variation across items and informants. Irritability, as measured by parent- and youth-report, was associated with variables in the externalizing (inattention, hyperactivity, executive dysfunction, aggression), internalizing (anxiety, depression, suicidality), and emotion regulation domains. Associations with reactive aggression, anger, dysregulation, and coping problems were especially pronounced. Irritability's links with internalizing and externalizing problems remained robust after controlling for demographic covariates.

LIMITATIONS

The sample was limited in diversity and moderate in size.

CONCLUSIONS

Findings support the reliability and validity of the ARI for assessing parent- and youth-rated irritability among clinically referred youth. Future research is needed to understand variations in irritability's manifestations, measurement, and correlates across demographic groups.