Impulsivity as key bridge symptoms in cross-sectional and longitudinal networks of ADHD and ODD.

BACKGROUND: Impulsivity is viewed as key to attention-deficit/hyperactivity disorder (ADHD) and disruptive behavior disorders (DBD). Yet, to date, no work has provided an item-level analysis in longitudinal samples across the critical developmental period from childhood into adolescence, despite prior work suggesting items exhibit differential relevance with respect to various types of impairment. The current study conducted a novel longitudinal network analysis of ADHD and oppositional defiant disorder (ODD) symptoms between childhood and adolescence, with the important applied prediction of social skills in adolescence. METHODS: Participants were 310 children over-recruited for clinical ADHD issues followed longitudinally for six years in total with gold standard diagnostic procedures and parent and teacher ratings of symptoms and social outcomes. RESULTS: Findings from baseline, Year 3, and Year 6 suggested Difficulty waiting turn, Blurts, and Interrupts/intrudes were key bridge items across cross-sectional and longitudinal parent-reported DBD networks. Furthermore, shortened symptom lists incorporating these symptoms were stronger predictors of teacher-rated social skills 5 years later compared to total DBD scores. CONCLUSIONS: Such findings are consistent with the trait impulsivity theory of DBD and ADHD and may inform useful screening tools and personalized intervention targets for children at risk for DBD during adolescence.

Evidence-Based Assessment for Attention-Deficit/Hyperactivity Disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects individuals from all life stages, genders, and races/ethnicities. Accurate assessment of ADHD across different populations is essential as undiagnosed ADHD is associated with numerous costly negative public health outcomes and is complicated by high comorbidity and developmental change in symptoms over time. Predictive analysis suggests that best-practice evidence-based assessment of ADHD should include both ADHD-specific and broadband rating scales from multiple informants with consideration of IQ, academic achievement, and executive function when there are concerns about learning. For children under age 12, parent and teacher ratings should be averaged. For adolescents and adults, informant reports should be prioritized when self- and other-report are inconsistent. Future research should provide more stringent evaluation of the sensitivity of measures to treatment response and developmental change over time as well as further validate measures on historically understudied populations (i.e., adults, women, and racial/ethnic minorities).

A Network Analysis of Executive Functions in Children and Adolescents With and Without Attention-Deficit/Hyperactivity Disorder.

This study applied network analysis to executive function test performances to examine differences in network parameters between demographically matched children and adolescents with and without attention-deficit/hyperactivity disorder (ADHD) (n = 141 per group; M = 12.7 ± 2.9 years-old; 72.3% boys, 66.7% White, 65.2% ≥ 12 years maternal education). All participants completed the NIH Toolbox Cognition Battery, including the Flanker, measuring inhibition, Dimensional Change Card Sort, measuring shifting, and List Sorting test, measuring working memory. Children with and without ADHD had comparable mean test performances (d range: .05-0.11) but presented with differences in network parameters. Among participants with ADHD, shifting was less central, had a weaker relationship with inhibition, and did not mediate the relationship between inhibition and working memory. These network characteristics were consistent with the executive function network structure of younger ages in prior research and may reflect an immature executive function network among children and adolescents with ADHD, aligning with the delayed maturation hypothesis.

Aging and Pubertal Development Differentially Predict Symptoms of ADHD, Depression, and Impairment in Children and Adolescents: An Eight-Year Longitudinal Study.

Activational effects of the reproductive neuroendocrine system may explain why some youths with ADHD are at greater risk for exacerbated ADHD symptoms (hyperactivity, inattention, impulsivity) during adolescence. For youths diagnosed with ADHD, first signs of ADHD symptoms become noticeable by multiple reporters (e.g., teachers, parents) when children enter schools, typically around kindergarten. The current study examined possible sex differences in ADHD, impairment, and comorbidity due to pubertal effects, as the role of pubertal development in ADHD is understudied. ADHD symptoms, depressive symptoms, impairment, and pubertal stage were assessed annually by multiple reporters in a well-characterized community sample of 849 children over-recruited for ADHD over eight years. Ages ranged from 7 to 13 years (38.16% female) at wave 1. Multilevel models indicated that males had higher levels of hyperactivity, impulsivity, and inattention than females, but that females had higher levels of impairment than males. Inattention symptoms did not show marked maturation changes. Hyperactivity and impulsivity declined as youth aged and impairment increased as youth aged. Lastly, depressive symptoms largely increased as youth aged and were higher amongst youth at later pubertal stages. Put together, aging and pubertal development are associated with improved ADHD symptoms but not for youth with high impairment. Findings from this study contributes to understanding the role that aging, pubertal status, and pubertal development plays in ADHD, impairment, and comorbidity in children and adolescents.

Data-Driven Methods for Predicting ADHD Diagnosis and Related Impairment: The Potential of a Machine Learning Approach.

Current diagnostic criteria for ADHD include several symptoms that highly overlap in conceptual meaning and interpretation. Additionally, inadequate sensitivity and specificity of current screening tools have hampered clinicians' ability to identify those at risk for related outcomes. Using machine learning techniques, the current study aimed to propose a novel algorithm incorporating key ADHD symptoms to predict concurrent and future (i.e., five years later) ADHD diagnosis and related impairment levels. Participants were 399 children with and without ADHD; multiple informant measures of ADHD symptoms, global impairment, academic performance, and social skills were included as part of an accelerated longitudinal design. Results suggested eight symptoms as most important in predicting impairment outcomes five years later: (1) Has difficulty sustaining attention in tasks or play activities, (2) Does not follow through on instructions and fails to finish work, (3) Has difficulty organizing tasks and activities, (4) Avoids tasks (e.g., schoolwork, homework) that require sustained mental effort, (5) Is often easily distracted, (6) Is often forgetful in daily activities, (7) Fidgets with hands or feet or squirms in seat, and (8) Interrupts/intrudes on others. The algorithm comprising this abbreviated list of symptoms performed just as well as or significantly better than one comprising all 18 symptoms in predicting future global impairment and academic performance, but not social skills. It also predicted concurrent and future ADHD diagnosis with 81-93% accuracy. Continued development of screening tools will be key to ensuring access to clinical services for youth at risk for ADHD.

Clarifying Relations Between ADHD and Functional Impairment in Adulthood: Utilization of Network and Machine Learning Approaches.

Using network analysis and random forest regression, this study identified attention-deficit/hyperactivity disorder (ADHD) symptoms most important for indicating impairment in various functional domains. Participants comprised a nationally representative sample of 1249 adults in the United States. Bridge symptoms were identified as those demonstrating unique relations with impairment domains that, in total, were stronger than those involving other symptoms. Results suggested three inattentive (i.e., difficulty organizing; does not follow through; makes careless mistakes) and one hyperactive (difficulty engaging in leisure activities) bridge symptoms. Random forest regression results supported bridge symptoms as most important (compared to other symptoms) for predicting global and specific impairment domains. Hyperactive/impulsive symptoms appeared more strongly related to impairment in women, whereas difficulty organizing and easily distracted appeared more related to impairment in men. Clarification of bridge symptoms may help identify core characteristics of ADHD in adulthood and specify screening and intervention targets to reduce risk for related impairment.

Utility of the Limited Prosocial Emotions Specifier in Preschoolers With Conduct Problems.

This study examined the clinical utility of the "Limited Prosocial Emotions" (LPE) specifier (i.e., prevalence rates, group differences, and predictive utility) in a high-risk preschool sample (N = 109, M age = 4.77) presenting with conduct problems (CPs; n = 59). First, LPE prevalence rates ranged from 7.7% to 89.8%. Next, few group differences were observed between with CP-only and CP+LPE; youth with CP+LPE differed from youth with CP-only on callous-unemotional (CU) traits and verbal ability, but not on externalizing or internalizing psychopathology, nor on parenting experiences. In the full sample, youth with LPE differed from youth without LPE on externalizing and internalizing psychopathology, parenting, and verbal ability. Finally, LPE predicted greater baseline CP but did not predict trajectories of CP. Findings highlight the clinical utility of the LPE specifier during early childhood and call for a refinement of the LPE specifier to improve its clinical value.

Etiological Networks of Attention-Deficit/Hyperactivity Disorder during Childhood and Adolescence.

OBJECTIVE: The purpose of the current study was to use network analysis techniques to parse relations between attention-deficit/hyperactivity disorder (ADHD) symptom domains, domains of executive function, and temperament traits. METHODS: Participants were 420 children aged 6-17 years (55% boys). The majority of the participants were Caucasian (72.86%) and 50% of the sample met diagnostic criteria for ADHD. Both parents and teachers provided ratings of participants' ADHD symptom severity. Parents completed questionnaires pertaining to participants' temperament traits, and participants completed well-validated laboratory measures of executive function. RESULTS: Results suggested effortful control as demonstrating the strongest relations with ADHD, particularly the parent-reported inattentive symptom domain. Additionally, negative effects appeared to demonstrate weaker but still notable relations primarily with the parent-reported hyperactive/impulsive symptom domain. Measures of executive function did not appear to demonstrate relations with any measures of ADHD symptoms or temperament traits. The results were generally replicated in a distinct sample (n = 732, 7-13 years, 63% boys, 81% White), although differences emerged pertaining to the role of surgency (i.e., related to the hyperactive/impulsive symptom domain in the replication but not the primary sample). CONCLUSIONS: Overall, findings provided support for the primary role of effortful control, as well as secondary roles for negative affect and surgency, as key risk markers for the characterization of ADHD. Additional exploration of the overlap between temperament and executive function, as pertaining to ADHD, may help clarify heterogeneity in phenotypes and suggest priorities for targeted interventions outside of traditional symptoms.

The unity and diversity of executive functions: A network approach to life span development.

As a novel approach to conceptualizing executive functions, this study applied network analysis to a common battery of executive function tests administered to a sample covering the life span. Participants (N = 3,944; age: M = 20.8 years, SD = 19.6, range: 3-85; maternal/self education: M = 12.9 years, SD = 2.6; 53.3% girls/women, 46.7% boys/men; 61.1% White, 18.2% African American, 14.0% Latinx, 6.8% other races/ethnicities) completed tests of inhibition, shifting, and updating/working memory. Zero-order and partial correlation network models were calculated for divided age groups, with network parameters compared between groups: edge weights, corresponding to zero-order or partial correlations between two executive functions; expected influence, quantifying centrality; and global strength, quantifying differentiation. Executive functions differentiated from childhood to adolescence and dedifferentiated during young adulthood, with further dedifferentiation at older adulthood. Shifting emerged as more central than other abilities in adolescence and adulthood versus childhood, with a mediational role of shifting between inhibition and updating/working memory. A network approach can appropriately capture the unity and diversity of executive functions, by which unity reflects the reciprocal engagement between diverse abilities to produce goal-directed behavior. The engagement between abilities, and a mediational role of shifting between inhibition and updating/working memory, may be necessary for the emergence of effective goal-directed behavior. Through a network approach, the unity of executive functions represents an emergent property of the dynamics between multiple abilities (e.g., inhibition, shifting, and updating/working memory) that, when working effectively in tandem, lead to integrative processes (e.g., problem solving) that contribute to successful executive behavior and goal attainment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Longitudinal Temperament Pathways to ADHD Between Childhood and Adolescence.

The current investigation extended prior cross-sectional mapping of etiological factors, transdiagnostic effortful and affective traits, and ADHD symptoms to longitudinal pathways extending from two etiological domains: polygenic and prenatal risk. Hypotheses were (1) genetic risk for ADHD would be related to inattentive ADHD symptoms in adolescence and mediated by childhood effortful control; (2) prenatal smoking would be related to hyperactive-impulsive ADHD symptoms during childhood and mediated by childhood surgency; and (3) there would be age-related variation, such that mediation of genetic risk would be larger for older than younger ages, whereas mediation of prenatal risk would be larger in earlier childhood than at later ages. Participants were 849 children drawn from the Oregon ADHD-1000 Cohort, which used a case control sample and an accelerated longitudinal design to track development from childhood (at year 1 ages 7-13) through adolescence (at year 6 ages 13-19). Results showed the mediational pathway from prenatal smoking through surgency to hyperactivity-impulsivity at Year 1 was significant (indirect effect estimate = .053, p < .01). The mediational pathway from polygenic risk through effortful control to inattention at Year 6 was also significant (indirect effect estimate = .084, p < .01). Both results were independent of the association between inattention and hyperactivity-impulsivity and control for the alternative etiological input and held across parent- and teacher-report of ADHD symptoms. In line with dual pathway models of ADHD, early prenatal risk for hyperactivity-impulsivity appears to operate through surgency, while polygenic genetic risk for inattention appears mediated by effortful control.

Networks of ADHD and SCT Symptoms in Emerging Adulthood.

OBJECTIVE: Emerging adulthood (18-25 years) is a transitional and understudied developmental period. Yet, little is known about how specific symptoms of ADHD, as well as those from the related SCT domain, may differentially relate to one another during this period, if there are differences based on biological sex, or how closely results will align with adulthood. METHODS: We used network analysis techniques to explore the structure of ADHD and SCT symptoms within emerging adulthood, with additional comparisons between sexes as well as between emerging adulthood and adulthood. Using an online platform, 8,506 adults reported on their symptoms of ADHD and SCT. RESULTS: Symptoms grouped together within their respective domains during emerging adulthood with no significant differences in overall network structure between sexes. Similarly, network structure appeared to be robust across emerging adulthood and adulthood. CONCLUSION: Such consistency supports a conceptualization of ADHD in emerging adulthood as similar to adulthood.

Longitudinal attention-deficit/hyperactivity disorder symptom networks in childhood and adolescence: Key symptoms, stability, and predictive validity.

The current study visualized attention-deficit/hyperactivity disorder (ADHD) symptom networks in a longitudinal sample of participants across childhood and adolescence with exploratory examination of age and gender effects. Eight hundred thirty-six children ages 7-13 years were followed annually for 8 years in total. Across parent and teacher report, results suggested "is easily distracted" and "difficulties sustaining attention" as central symptoms across three testing points (i.e., Year 1, Year 3, and Years 5-8 collapsed). "Difficulties following instructions" and "intrudes/interrupts" also emerged as parent-reported central symptoms. Assessment of network structure across the three testing points suggested global robustness of relations among ADHD symptoms from midchildhood into early adolescence. However, relations among symptoms that cause problems in school settings (i.e., being easily distracted) were stronger in teacher-reported than parent-reported networks. When aggregated into a sum score, central symptoms during Year 1 predicted total difficulties related to mental health problems 5 years later just as well as all 18 symptoms. Central symptoms of ADHD may be useful as screeners of future emotional and behavioral difficulties. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Identifying the Inter-Domain Relations Among ODD, CD, and CU Traits in Preschool Children Using Network Analysis.

Oppositional defiant disorder (ODD) and conduct disorder (CD) are two of the most common forms of disruptive behavior disorders during childhood. Callous-unemotional (CU) traits are an important factor in understanding the presentation of these externalizing forms of psychopathology. ODD, CD, and CU traits are highly related constructs, yet little work has examined how these externalizing forms of psychopathology are related at the domain level. The current study utilized network analysis to identify the distinct domains that explain the associations among ODD, CD, and CU traits. In a sample of 104 preschoolers (M age = 4.76), results demonstrated that the symptom domains of (a) angry/irritable mood and argumentative/defiant behavior, (b) aggression to people and animals, and (c) callousness were the primary bridge domains for ODD, CD, and CU traits, respectively. Findings of the current study offer a more nuanced insight into the relations amongst ODD, CD, and CU traits. Identification of bridge symptom domains can inform intervention practices by targeting specific symptom domains that are contributing to the maintenance of such aggressive and disruptive behaviors.

Multiple informant average integration of ADHD symptom ratings predictive of concurrent and longitudinal impairment.

To date, there remains no consensus about the best evidence-based method for integrating multiple informant data in the diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD). Several approaches exist, including the psychometrically sound approach of averaging scores, as well as the use of "OR" and "AND" algorithms, which are still commonly used in research. The current study tested these major integration methods in their concurrent and longitudinal prediction of clinician-rated impairment, teacher-rated academic, and parent- and self-rated social skill ratings in children overrecruited for ADHD across a 6-year span from childhood to adolescence. The sample included a total of 800 children, 480 with ADHD, ages 6 to 13, who completed a "gold standard" assessment of ADHD and associated impairment. Overall, the "OR," "AND," and average integration approaches showed significantly high interrelations with one another (r range from .78 to .96) and were all significantly and strongly related to impairment measures concurrently and longitudinally. Multivariate regressions demonstrated that the average integration approach concurrently and longitudinally out predicted the other two approaches. Results demonstrated that the average approach slightly outperformed the other two in its prediction of concurrent and longitudinal clinician-rated impairment, teacher-rated academic skills, and parent- and self-rated child social skills across childhood and adolescence. Evidence-based assessment integration of parent and teacher ratings of ADHD in childhood might best utilize an averaging approach, as it is most related to later impairment ratings, particularly if such findings are replicated by other groups. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Binaural Modelling and Spatial Auditory Cue Analysis of 3D-Printed Ears.

In this work, a binaural model resembling the human auditory system was built using a pair of three-dimensional (3D)-printed ears to localize a sound source in both vertical and horizontal directions. An analysis on the proposed model was firstly conducted to study the correlations between the spatial auditory cues and the 3D polar coordinate of the source. Apart from the estimation techniques via interaural and spectral cues, the property from the combined direct and reverberant energy decay curve is also introduced as part of the localization strategy. The preliminary analysis reveals that the latter provides a much more accurate distance estimation when compared to approximations via sound pressure level approach, but is alone not sufficient to disambiguate the front-rear confusions. For vertical localization, it is also shown that the elevation angle can be robustly encoded through the spectral notches. By analysing the strengths and shortcomings of each estimation method, a new algorithm is formulated to localize the sound source which is also further improved by cross-correlating the interaural and spectral cues. The proposed technique has been validated via a series of experiments where the sound source was randomly placed at 30 different locations in an outdoor environment up to a distance of 19 m. Based on the experimental and numerical evaluations, the localization performance has been significantly improved with an average error of 0.5 m from the distance estimation and a considerable reduction of total ambiguous points to 3.3%.

Commentary: Extending longitudinal network approaches - a reflection on Funkhouser et al. (2020).

The network approach facilitates an exploration of direct and potentially causal relations among symptoms of psychological disorders, yet most prior research utilizing this approach has done so using cross-sectional data. This commentary highlights the importance of longitudinal network approaches, as depicted in the study conducted by Funkhouser et al. (Journal of Child Psychology and Psychiatry, 2020), and describes two possible key extensions of this approach: (a) accounting for risk markers, etiological mechanisms, and other nonsymptoms within longitudinal network models, and (b) continued exploration of longitudinal within-person networks with attention to personalized treatment applications. Inclusion of these extensions in future longitudinal network studies could provide new insights into the nature of psychopathology and inform the development of more precise screening tools and targeted, personalized interventions.

Longitudinal network model of the co-development of temperament, executive functioning, and psychopathology symptoms in youth with and without ADHD.

Attention Deficit Hyperactivity Disorder (ADHD) is a common, chronic, and impairing disorder, yet presentations of ADHD and clinical course are highly heterogeneous. Despite substantial research efforts, both (a) the secondary co-occurrence of ADHD and complicating additional clinical problems and (b) the developmental pathways leading toward or away from recovery through adolescence remain poorly understood. Resolving these requires accounting for transactional influences of a large number of features across development. Here, we applied a longitudinal cross-lagged panel network model to a multimodal, multilevel dataset in a well-characterized sample of 488 children (nADHD=296) to test Research Domain Criteria initiative-inspired hypotheses about transdiagnostic risk. Network features included DSM symptoms, trait-based ratings of emotional functioning (temperament), and performance-based measures of cognition. Results confirmed that ADHD symptom domains, temperamental Irritability, and Working Memory are independent transdiagnostic risk factors for psychopathology based on their direct associations with other features across time. ADHD symptoms and working memory each had direct, independent associations with depression. Results also demonstrated tightly linked co-development of ADHD symptoms and temperamental Irritability, consistent with the possibility that this type of anger dysregulation is a core feature that is co-expressed as part of the ADHD phenotype for some children.

Subgroups of Childhood ADHD Based on Temperament Traits and Cognition: Concurrent and Predictive Validity.

Efforts to parse ADHD's heterogeneity in the DSM system has generally relied on subtypes, or presentations, based on different symptom combinations. Promising recent work has suggested that biologically-relevant and clinically predictive subgroups may be identified via an alternative feature set based on either a) temperament traits or b) executive function measures. Yet, the potential additive ability of these domains for specifying ADHD sub-phenotypes remains unknown. We thus sought to determine whether temperament traits and executive function, together, could facilitate a more nuanced and clinically meaningful subgrouping of children with ADHD. Participants included 828 children aged 7-11 years (62% with ADHD, 38% female). Latent profile and community detection analyses using both temperament and cognitive input features provided support for a primarily temperament-based three-subgroup solution (i.e., "Mild," "Irritable," and "Surgent"), although the distinction between Surgent and Mild subgroups may have been better explained as an ADHD symptom severity effect. There was also evidence of a five-subgroup solution, in which cognitive measures differentiated the Surgent subgroup into those with and without cognitive impairment. Cognitive measures also appeared to differentiate the Irritable subgroup based on severity, although differences in resulting subgroups appeared better explained via differences in negative affect and shyness. Subgroups within the five-subgroup solution meaningfully differed with respect to concurrent comorbidity. The utility of the five-subgroup solution for predicting comorbid diagnoses 2 years later was more limited. Additional work is needed to fully characterize the integration of cognitive and affective functioning in ADHD and their overlapping or additive value for clinical prediction.

Conceptualizing the UPPS-P model of impulsive personality through network analysis: Key dimensions and general robustness across young adulthood.

OBJECTIVE: Within the UPPS-P model of impulsive personality, negative urgency, positive urgency, lack of premeditation, lack of perseverance, and sensation seeking dimensions have been linked to unique etiological mechanisms and outcomes. Yet, additional research is needed exploring direct relations among dimensions to determine how these relations may contribute to the nature of impulsive personality and its correlates. The current study used network analysis to clarify relations among UPPS-P dimensions and assess global robustness of these relations across young adulthood. METHOD: Participants included a longitudinal sample of 525 college students (48% male, 18-26 years) who completed the UPPS-P once per year for three consecutive years. RESULTS: Network structure was globally robust with particularly strong relations emerging between positive and negative urgency, as well as between lack of premeditation and lack of perseverance, across waves. Lack of premeditation consistently emerged as a central dimension. Additional analyses suggested lack of premeditation and sensation seeking as most robustly related with retrospectively reported frequency of alcohol use. CONCLUSIONS: Results suggested general robustness in the relations among impulsive personality dimensions, with relations involving lack of premeditation being particularly important for characterizing impulsive personality's nature. Sensation seeking and lack of premeditation may warrant particular focus when linking impulsive personality with frequency of alcohol use.