Observed temperament from ages 6 to 36 months predicts parent- and teacher-reported attention-deficit/hyperactivity disorder symptoms in first grade

The Developmental Unfolding of ADHD Symptoms from Early Childhood Through Adolescence: Early Effects of Exuberant Temperament, Parenting and Executive Functioning

Temperament, parenting, and executive functioning (EF) are individual and contextual factors that have been identified to play a role in the development of Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms. Specifically, exuberant temperament in toddlerhood has been associated with both adaptive and maladaptive outcomes, including ADHD symptoms. Therefore, it is important to understand factors that predict which exuberant children experience increased ADHD symptoms and the specific mechanisms through which early exuberant temperament impacts later ADHD symptoms. Using a multi-method, prospective longitudinal design, this study examined a moderated mediation model wherein the interactive effects of observed exuberance and parenting at age 3 predicted the development of parent-reported ADHD symptoms from childhood through adolescence (age 5, 7, 9, 12, and 15) via child EF (i.e., inhibitory control) at age 4. Parent-child dyads (n = 291) from a longitudinal study on child temperament were included. A piecewise model of ADHD symptom growth demonstrated stability in ADHD symptoms from age 5-9 and a decrease from age 9-15. Results support a moderated mediation model wherein an increase in ADHD symptoms throughout childhood was predicted from early childhood exuberant temperament by way of EF, but only for children whose parents displayed less directive parenting. Findings suggest identifiable early markers of risk, including temperament, parenting, and EF- pointing to possible targets for early intervention/prevention.

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.

Temperamental and psychomotor predictors of ADHD symptoms in children born after a threatened preterm labour: a 6-year follow-up study

Children born after threatened preterm labour (TPL), regardless of whether it ends in preterm birth, may represent an undescribed "ADHD cluster". The aim of this cohort study is to identify early temperament and psychomotor manifestations and risk factors of TPL children who present ADHD symptoms. One hundred and seventeen mother-child pairs were followed from TPL diagnosis until the child's 6 years of life. TPL children were divided according to the prematurity status into three groups: full-term TPL (n = 26), late-preterm TPL (n = 53), and very-preterm TPL (n = 38). A non-TPL group (n = 50) served as control. Temperament and psychomotor development at age 6 months and ADHD symptoms at age 6 years were assessed. Perinatal and psychosocial factors were also recorded. All TPL groups showed higher severity of ADHD symptoms compared with non-TPL children (difference in means + 4.19 for the full-term group, + 3.64 for the late-preterm group, and  + 4.99 for the very-preterm group, all ps < 0.021). Concretely, very-preterm and late-preterm TPL children showed higher restless/impulsive behaviours, whereas full-term TPL children showed higher emotional lability behaviours. Higher surgency/extraversion and delayed fine motor skills at age 6 months predicted ADHD symptoms at 6 years in TPL children. Male sex, maternal state anxiety symptoms at TPL diagnosis, low parental education, and past maternal experience of traumatic events predicted higher ADHD symptoms in TPL children. Therefore, TPL children may have a higher risk for developing ADHD symptoms, presenting a phenotype that depends on the prematurity status. Moreover, the specific combination of early manifestations and risk factors suggests that TPL children may conform an undescribed group at-risk of ADHD symptoms.

Delineating early developmental pathways to ADHD: Setting an international research agenda

Background

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent, impairing, and highly heritable condition typically diagnosed in middle childhood. However, it is now recognized that symptoms emerge much earlier in development. Research focused on understanding-using multiple units of analysis-the cascade of early-life (i.e., prenatal-infant-toddler) developmental changes that will later emerge as ADHD has the potential to transform early identification, prevention, and intervention. To this end, we introduce the recently established Early ADHD Consortium, an international network of investigators engaged in prospective, longitudinal studies of risk for ADHD beginning early in life, conducted within a developmental framework, and which incorporate multimethod approaches. This network seeks to harmonize measures and methodological approaches to increase the potential for data sharing and subsequent impact.

Methods

This perspective paper highlights the importance of investigating pre-diagnostic markers of ADHD, and potential models and mechanisms of ADHD risk and development, with the long-term objective of facilitating development of preemptive interventions that will minimize the impact of ADHD symptoms on everyday functioning and maximize health and developmental outcomes.

Results

We selectively describe key challenges and questions for this field related to theoretical models and developmental mechanisms in ADHD and recommend next steps for the science, including methodological, measurement, and study design considerations. We then describe potential implications for preemptive intervention development. We conclude by considering other issues including ethical concerns and the critical value of incorporating stakeholder input.

Conclusions

It is hoped that this perspective puts forth a research agenda that will enhance collaborative efforts and accelerate progress in understanding developmental mechanisms and the early ADHD phenotype, with implications for early intervention enhancement of healthy development for infants, young children, and their families.

Research Review: A systematic review and meta-analysis of infant and toddler temperament as predictors of childhood attention-deficit/hyperactivity disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with onset as early as preschool and impairment across the lifespan. Temperament factors, specifically those that theoretically map onto ADHD symptoms, may be early markers of risk for developing later childhood ADHD that could be identifiable in infancy or toddlerhood. This meta-analysis examined the associations between these early temperamental factors and later symptoms and diagnosis of ADHD and mapped early temperament constructs onto the three ADHD symptom dimensions.

METHODS

A systemic review of the literature was conducted to identify prospective longitudinal studies that included theoretically relevant temperament constructs (sustained attention, activity level, inhibition, and negative emotionality) examined from birth to 36 months old and ADHD (symptoms or diagnosis) in preschool or childhood. The association between each temperament construct and ADHD outcomes was examined using pooled standardized estimates in meta-analyses.

RESULTS

Forty-eight articles (n = 112,716 infants/toddlers) prospectively examined temperament and the relation to childhood ADHD symptoms or diagnosis. Activity level (k = 18) in infancy and toddlerhood was moderately associated with childhood ADHD (r = .39, CI = 0.27, 0.51, p < .001). Moderate effect sizes were also observed for sustained attention (k = 9; r = -.28, CI = -0.42, -0.12, p < .001) and negative emotionality (k = 33; r = .25, CI = 0.16, 0.34, p < .001) with ADHD. The specificity of each temperament construct for later ADHD symptom dimensions was such that activity level and negative emotionality were predictive of all three symptom dimensions (i.e., inattention, hyperactivity/impulsivity, and combined), whereas sustained attention was only associated with combined symptoms.

CONCLUSIONS

Infant and toddler temperament is an early risk factor for the development of childhood ADHD that could be utilized for early intervention identification. Yet, this systematic review found that relatively few prospective longitudinal studies have examined sustained attention (k = 9) and inhibition (k = 15) in infancy and toddlerhood in relation to later ADHD highlighting the need for further research.

Preschool development, temperament and genetic liability as early markers of childhood ADHD: A cohort study

Background

ADHD is associated with multiple adverse outcomes and early identification is important. The present study sets out to identify early markers and developmental characteristics during the first 30 months of life that are associated with ADHD 6 years later.

Methods

9201 participants from the prospective Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort were included. Outcome measures were parent-rated ADHD symptom scores (Strengths and Difficulties Questionnaire, SDQ) and ADHD diagnosis (Development and Wellbeing Assessment, DAWBA) at age 7. Seventeen putative markers were identified from previous literature and included: pre- and peri-natal risk factors, genetic liability (ADHD polygenic risk scores, PRS), early development, temperament scores and regulatory problems. Associations were examined using regression analysis.

Results

Univariable regression analysis showed that multiple early life factors were associated with future ADHD outcomes, even after controlling for sex and socio-economic status. In a multivariable linear regression model; temperament activity scores (B = 0.107, CI = 0.083-0.132), vocabulary delay (B = 0.605, CI = 0.211-0.988), fine motor delay (B = 0.693, CI = 0.360-1.025) and ADHD PRS (B = 0.184, CI = 0.074-0.294) were associated with future symptoms (R ² = 10.7%). In a multivariable logistic regression model, ADHD PRS (OR = 1.39, CI = 1.10-1.77) and temperament activity scores (OR = 1.09, CI = 1.04-1.16) showed association with ADHD diagnosis.

Conclusion

As well as male sex and lower socio-economic status, high temperament activity levels and motor and speech delays in the first 30 months of life, are associated with childhood ADHD. Intriguingly, given that genetic risk scores are known to explain little of the variance of ADHD outcomes, we found that ADHD PRS added useful predictive information. Future research needs to test whether predictive models incorporating aspects of early development and genetic risk scores are useful for predicting ADHD in clinical practice.

Individual differences in sensitivity to positive home environment among children "at risk" for attention-deficit/hyperactivity disorder: A review

Although the evidence for the genetic basis of attention-deficit/hyperactivity disorder (ADHD) is strong, environmental factors, such as the quality of parenting or the home environment, may moderate such genetic liability. The plausible negative effect of a low-quality home environment and negative parenting on child outcomes is well-established; however, the positive effect of a high-quality environment and positive parenting remained largely uninvestigated. Due to the presence of genetic, temperamental, or physiological factors, children who were traditionally considered at-risk for ADHD may be more sensitive to aspects of their environment compared to children who are not at such risk. Therefore, they would be more affected by their environmental experience, either for good or bad. Under supportive environmental conditions, such at-risk individuals might actually outperform their non-vulnerable peers, suggesting that these individual factors might be considered susceptibility factors rather than risk factors. Little is known regarding the positive effect of the environment in the ADHD literature, but it has been demonstrated in cognitive functions that are closely associated with ADHD, such as executive functions (EF). We review this literature and examine the extant empirical support for sensitivity to aspects of the home environment and parenting in the case of ADHD and EF. Moreover, we review factors that could help identify the specific aspects of the home environment and parenting that these children might be more susceptible to. Such knowledge could be valuable when designing preventive interventions and identifying those children that are especially sensitive and could benefit from such interventions. Recommendations for future studies are discussed as well.

Parent ADHD Is Associated With Greater Parenting Distress in the First Year Postpartum

OBJECTIVE

Little is known about the experience of parenting infants when a mother or father has ADHD. This study examined cross-sectional predictors of parenting distress experienced by parents with and without ADHD who also have infants.

METHODS

Participants were 73 mother-father pairs (N = 146) of infants 6 to 10 months old. Half of the families included a parent with ADHD. Psychosocial predictors were tested using multilevel modeling.

RESULTS

Parent or partner ADHD, lower parent sleep quality, fewer social supports, and less infant surgency and effortful control were associated with greater parental distress. Infant negative affect and sleep were not associated.

CONCLUSIONS

Parents with ADHD and their partners experience greater parenting distress in the first year of their child's life than parents without ADHD. Addressing parent ADHD symptoms and co-occurring difficulties, including sleep disturbances, are potential targets for early interventions to maximize both parent and infant mental health outcomes.

Systematic Review and Meta-analysis: The Science of Early-Life Precursors and Interventions for Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To evaluate which early neurocognitive and behavioral precursors are associated with the development of attention-deficit/hyperactivity disorder (ADHD) and whether these are currently targeted in early interventions.

METHOD

We conducted 2 systematic reviews and meta-analyses of empirical studies to examine the following: (1) early-life (0-5 years) neurocognitive and behavioral precursors associated with familial likelihood for ADHD, an early ADHD diagnosis/elevated ADHD symptoms, and/or the presence of later-childhood ADHD; and (2) interventions delivered to children aged 0 to 5 years targeting the identified precursors or measuring these as outcomes. Standardized mean differences (Hedges' g) and pre-post-treatment change scores (SMD) were computed.

RESULTS

A total of 149 studies (165,095 participants) investigating 8 neurocognitive and behavioral domains met inclusion criteria for part 1. Multi-level random-effects meta-analyses on 136 studies revealed significant associations between ADHD and poorer cognitive (g = -0.46 [95% CIs: -0.59, -0.33]), motor (g = -0.35 [CIs: -0.48, -0.21]) and language (g = -0.43 [CIs: -0.66, -0.19]) development, social (g = 0.23 [CIs: 0.03, 0.43]) and emotional (g = 0.46 [CIs: 0.33, 0.58]) difficulties, early regulatory (g = 0.30 [CIs: 0.18, 0.43]) and sleep (g = 0.29 [CIs: 0.14, 0.44]) problems, sensory atypicalities (g = 0.52 [CIs: 0.16, 0.88]), elevated activity levels (g = 0.54 [CIs: 0.37, 0.72]), and executive function difficulties (g = 0.34 [CIs: 0.05, 0.64] to -0.87 [CIs: -1.35, -0.40]). A total of 32 trials (28 randomized, 4 nonrandomized, 3,848 participants) testing early interventions that targeted the identified precursors met inclusion criteria for part 2. Multi-level random-effects meta-analyses on 22 studies revealed significant intervention-related improvements in ADHD symptoms (SMD = 0.43 [CIs: 0.22, 0.64]) and working memory (SMD = 0.37 [CIs: 0.06, 0.69]).

CONCLUSION

Children aged 0 to 5 years with current or later-emerging ADHD are likely to experience difficulties in multiple neurocognitive/behavioral functions. Early interventions show some effectiveness in reducing ADHD symptoms, but their effects on neurocognitive/behavioral difficulties require further study.

Temperament Dimensions and Awakening Cortisol Levels in Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To investigate whether temperament dimensions, Effortful Control (EC), Surgency-Extraversion (SE), and Negative Affectivity (NA), are associated with attention-deficit/hyperactivity disorder (ADHD) and how they relate to awakening cortisol levels, as a proxy measure of peripheral arousal.

METHODS

Parent-rated temperament and saliva samples were collected from 55 children with ADHD and 65 age-matched controls.

RESULTS

Compared to controls, youths with ADHD showed lower EC, higher NA, and lower awakening cortisol levels but did not differ in SE. Similar findings emerged in dimensional analyses linking temperament traits to inattention and hyperactivity-impulsivity symptoms. The results remained unchanged when controlling for the presence of co-occurring opposition-defiance and anxiety traits, as well as medication status. Temperament dimensions were not associated with cortisol levels.

CONCLUSIONS

Poor temperamental emotional and cognitive self-regulation showed significant associations with ADHD but did not appear to be linked to the under-arousal typically seen in ADHD.

Early development of negative and positive affect: Implications for ADHD symptomatology across three birth cohorts

High levels of early emotionality (of either negative or positive valence) are hypothesized to be important precursors to early psychopathology, with attention-deficit/hyperactivity disorder (ADHD) a prime early target. The positive and negative affect domains are prime examples of Research Domain Criteria (RDoC) concepts that may enrich a multilevel mechanistic map of psychopathology risk. Utilizing both variable-centered and person-centered approaches, the current study examined whether levels and trajectories of infant negative and positive emotionality, considered either in isolation or together, predicted children's ADHD symptoms at 4 to 8 years of age. In variable-centered analyses, higher levels of infant negative affect (at as early as 3 months of age) were associated with childhood ADHD symptoms. Findings for positive affect failed to reach statistical threshold. Results from person-centered trajectory analyses suggest that additional information is gained by simultaneously considering the trajectories of positive and negative emotionality. Specifically, only when exhibiting moderate, stable or low levels of positive affect did negative affect and its trajectory relate to child ADHD symptoms. These findings add to a growing literature that suggests that infant negative emotionality is a promising early life marker of future ADHD risk and suggest secondarily that moderation by positive affectivity warrants more consideration.

Treatment Response among Preschoolers with Disruptive Behavior Disorders: The Role of Temperament and Parenting

Objective: This study examined associations between temperament (negative affect, effortful control, and surgency) and symptoms of attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) within a diverse preschool sample. Interactions between temperament and parenting in the prediction of ADHD/ODD symptoms before and after an 8-week early intervention program (i.e., Summer Treatment Program for Pre-kindergartners; STP-PreK) were also examined.Method: The sample included 215 children (Mage = 5.0, 80.9% male, 84.7% Latinx) with a diagnosis of ADHD and/or ODD who completed the STP-PreK. Temperament was measured via parent report while ADHD/ODD symptoms were assessed via combination of parent and teacher report. Positive and negative parenting were assessed via rating scales and a standardized parent-child interaction observation.Results: Higher surgency was associated with greater symptom severity of ADHD/ODD pre- and post-treatment. Higher negative affect was associated with greater symptom severity of ODD pre- and post-treatment, while higher effortful control was only associated with lower symptom severity of inattention pre-treatment. Positive parenting predicted lower symptom severity of ADHD/ODD post-treatment. Moderation analyses indicated that the benefits of low levels of negative parenting only occurred when paired with low temperament risk for symptoms of hyperactivity and ODD. Additionally, only the combination of high surgency and high observed negative parenting resulted in greater symptom severity of ODD. Finally, decreases in inconsistent discipline predicted decreases across all symptom domains post-treatment.Conclusions: Our findings add to the temperament-based model of ADHD/ODD by highlighting temperament's unique prediction of treatment response as well as important interactions with the caregiving environment.

An Exploration of Sleep and Family Factors in Young Children at Familial Risk for ADHD

Objective: The aim of the current study was to examine relations between sleep problems and family factors and early markers of ADHD in young children with and without a familial risk for ADHD.Methods: Differences in sleep behavior and family functioning in children under 6 years with (n = 72) and without (n = 139) a familial risk for ADHD were investigated. The influence of family and sleep factors on the development of early temperament markers of ADHD (effortful control and negative affect) was explored. Parents/caregivers completed questionnaires on family functioning, child sleep behavior, and general regulatory behaviors.Results: A significant difference was observed between high-risk and low-risk groups for family functioning in the infant/toddler (<3 years) and preschool (>3 years) cohorts. Parents of infants/toddlers in the high-risk group reported poorer infant sleep. However, there were no sleep differences reported for the preschool cohort. Family functioning was found to predict effortful control, while sleep quality predicted negative affect.Conclusion: The results of this study highlight potential family and sleep issues for young children with a familial history of ADHD and the potential influence of these factors on early temperament markers of ADHD. Future research should explore these relations further in order to better establish whether early sleep and family interventions could mitigate later ADHD symptomatology.

Can Familial Risk for ADHD Be Detected in the First Two Years of Life?

Objective: We evaluated trajectories of attention-deficit/hyperactivity (ADHD)-relevant behaviors in a sample of infants at high and low familial risk for ADHD who were prospectively evaluated at 12, 18, and 24 months of age.Method: Participants included 43 infants at risk for ADHD based on family history (i.e., diagnosed first-degree relative) and 40 low-risk infants (i.e., no family history of ADHD). Instances of inattention, out-of-seat, and grabbing behavior were coded from video; analogous constructs were rated by examiners unaware of familial risk status after completing structured standardized assessments with the infants/toddlers. At the end of each study visit, examiners solicited parents' concerns about their child's behavior. Differences in ADHD-related behaviors and parent concerns were examined between 12 and 24 months of age.Results: Infants with an older sibling or parent diagnosed with ADHD were distinguishable from infants with no family history of ADHD as early as 12 months of age based on directly observed and examiner reports of behavior, particularly with respect to hyperactive-impulsive behavior. Parents of infants at familial risk for ADHD also reported significantly more behavior/temperament concerns as early as 12 months of age compared to parents of infants at low risk for ADHD.Conclusions: These findings highlight the ability to detect genetic liability for ADHD by the end of the first year of life, suggesting that well-designed family risk studies of ADHD are feasible and may be clinically valuable. They also suggest the potential for earlier detection of risk for ADHD than has previously been possible.

A person-centered approach to understanding child temperament at ages 3 and 6

Person-centered analyses, such as latent profile analysis, provide an approach to assessing individual differences in child temperament that aligns with typological theory and is well positioned for translation to applied settings. In a community sample, latent profile analysis was conducted using seven temperament traits assessed through laboratory observation when children were three- and six-years-old. At age 3, a four-class model fit best and subgroups were labeled “typical,” “sluggish,” “surgent,” and “dysregulated,” based on the pattern of class-specific means. A five-class model fit best at age 6 and subgroups were labeled “typical,” “sluggish,” “outgoing,” “active-impulsive” and “negative affect.” Associations between class membership and mother-reported temperament traits, concurrently assessed, were mostly consistent with the class identities. Comparison of subgroup membership across waves generally demonstrated patterns of continuity across groups characterized by similar trait patterns. This paper provides an illustrative guide for temperament researchers in the implementation of latent profile analysis, addressing important methodical considerations. Increased utilization of person-centered approaches like latent profile analysis could lead to important advances in the study of child temperament, such as improved understanding of the continuity of temperamental styles and more targeted risk assessment.

Developmental trajectories of ADHD symptoms in a large population-representative longitudinal study

BACKGROUND

Previous research has suggested that there is substantial heterogeneity in the developmental trajectories of attention-deficit/hyperactivity disorder (ADHD) symptoms. Sometimes, qualitative distinctions between trajectories with different ages of onset and/or patterns of remission are made; however, little is known about the predictors and broader clinical meaningfulness of these candidate 'developmental subtypes' of ADHD symptoms.

METHODS

We applied latent class growth analysis to data from the UK Millennium Cohort Study (MCS; N = 11 316; ages 3, 5, 7, 11 and 14) to evaluate whether developmental trajectories of ADHD symptoms differing in early life predictors could be identified. Our optimal model included six trajectory groups, labelled unaffected (34.9% of the sample), mildly affected (24.1%), subclinical remitting (12.8%), pre-school onset partially remitting (14.1%), developmentally increasing (7.6%) and pre-school onset persistent (6.4%).

RESULTS

Factors such as gender, conduct problems, cognitive ability, maternal education, premature birth, peer problems and school readiness scores differentiated between specific ADHD symptom trajectories.

CONCLUSIONS

Taken together, our findings provide preliminary evidence that distinguishing different trajectories of ADHD symptoms could be clinically informative.

Maternal Parenting and Toddler Temperament: Predictors of Early School Age Attention-Deficit/Hyperactivity Disorder-Related Behaviors

Detection of early risk for developing childhood attention-deficit/hyperactive disorder (ADHD) symptoms, inattention and hyperactivity, may be critical for prevention and early intervention. Temperament and parenting are two promising areas of risk, representing potential targets for preventive intervention; however, studies have rarely tested these factors longitudinally using multiple methods and reporters. In a longitudinal sample of 312 low-income boys, this study tested the hypothesis that negative emotionality (NE) and effortful control (EC) in toddlerhood (1.5-3.5 years old) would predict mother- and teacher-reported ADHD-related behaviors at school age (5-7 years old). Direct effects of observed warm, supportive and harsh maternal parenting were tested in relation to ADHD-related behaviors and as moderators of associations between NE and EC and ADHD-related behaviors. Several predictions were supported: 1) Greater maternal-reported toddler NE positively predicted mother-reported ADHD behaviors; 2) Greater observed EC was associated with fewer mother- and teacher-reported ADHD-related behaviors; 3) Warm, supportive parenting predicted fewer teacher-reported ADHD-related behaviors, and harsh parenting predicted more ADHD-related behaviors as reported by parents and teachers; 4) Harsh parenting moderated the association between observed EC and mother-reported ADHD-related behaviors. Together, the findings suggest that lower child EC, lower warm/supportive parenting, and greater harsh parenting in toddlerhood independently signal increased risk for later ADHD-related behaviors; further, the association between low EC and ADHD-related behaviors was amplified in the context of high levels of harsh parenting.

"My Brain Can Stop": An ERP Study of Longitudinal Prediction of Inhibitory Control in Adolescence

We examined the longitudinal predictors of electrophysiological and behavioral markers of inhibitory control in adolescence. Participants were 63 adolescent boys who have been followed since birth as part of a prospective longitudinal study on the developmental pathways to attention-deficit hyperactivity disorder (ADHD). At 17 years of age, they completed the stop-signal task (SST) while electroencephalography (EEG) was continuously recorded. Inhibitory control was evaluated by the stop-signal reaction time (SSRT) as well as by the amplitude of the event-related potential (ERP) component of N2 during successful inhibition. We found that higher inattention symptoms throughout childhood predicted reduced amplitude (i.e., less negative) of the N2 in adolescence. Furthermore, the N2 amplitude was longitudinally predicted by the early precursors of child familial risk for ADHD and early childhood temperament. Specifically, father's inattention symptoms (measured in the child's early infancy) and child's effortful control at 36 months of age directly predicted the N2 amplitude in adolescence, even beyond the consistency of inattention symptoms throughout development. The SSRT was predicted by ADHD symptoms throughout childhood but not by the early precursors. Our findings emphasize the relevance of early familial and temperamental risk for ADHD to the prediction of a later dysfunction in inhibitory control.

Predicting ADHD symptoms and diagnosis at age 14 from objective activity levels at age 7 in a large UK cohort

Hyperactivity is one of the three core symptoms in children with attention deficit hyperactivity disorder (ADHD). Diagnosing ADHD typically involves self-report, third party report and observations. Objective activity data can make a valuable contribution to the diagnostic process. Small actigraphy studies in clinical samples have shown that children with ADHD move more than children without ADHD. However, differences in physical activity between children with and without ADHD have not been assessed in large community samples or longitudinally. This study used data from the Millennium Cohort Study to test whether symptoms of ADHD (parent-rating Strengths and Difficulties Questionnaire) and ADHD diagnosis at age 14 (reported by parents) could be predicted from objective activity data (measured with actigraphs) at age 7 in N = 6675 children (final N = 5251). Regressions showed that less sedentary behavior at age 7 predicted more ADHD symptoms at age 14 (β =  - 0.002, CI  - 0.004 to  - 0.001). The result remained significant when controlled for ADHD symptoms at age 7, sex, BMI, month of birth, SES and ethnicity (β  =  - 0.001, CI  - 0.003 to  - 0.0003). ADHD diagnosis at age 14 was also significantly predicted by less sedentary behavior at age 7 (β  =  - 0.008). Our findings show that symptoms of ADHD can be predicted by objective activity data 5 years in advance and suggest that actigraphy could be a useful instrument aiding an ADHD diagnosis. Interestingly, the results indicate that the key difference between children with and without ADHD lies in reduced sedentary activity, i.e., times of rest.

Development of ADHD: Etiology, Heterogeneity, and Early Life Course

ADHD represents a powerful entry point for developmental approaches to psychopathology due to its major role in early emergence of major life problems. One key issue concerns the role of early environmental risks in etiology and maintenance in the context of genetic liability. Here, psychosocial aspects of development need more attention. A second key issue is that phenotypic heterogeneity requires better resolution if actionable causal mechanisms are to be effectively identified. Here, the interplay of cognition and emotion in the context of a temperament lens is one helpful way forward. A third key issue is the poorly understood yet somewhat striking bifurcation of developmental course in adolescence, when a subgroup seem to have largely benign outcomes, while a larger group continue on a problematic path. A final integrative question concerns the most effective conceptualization of the disorder in relation to broader dysregulation. Key scientific priorities are noted.

Development of ADHD: Etiology, Heterogeneity, and Early Life Course

ADHD represents a powerful entry point for developmental approaches to psychopathology due to its major role in early emergence of major life problems. One key issue concerns the role of early environmental risks in etiology and maintenance in the context of genetic liability. Here, psychosocial aspects of development need more attention. A second key issue is that phenotypic heterogeneity requires better resolution if actionable causal mechanisms are to be effectively identified. Here, the interplay of cognition and emotion in the context of a temperament lens is one helpful way forward. A third key issue is the poorly understood yet somewhat striking bifurcation of developmental course in adolescence, when a subgroup seem to have largely benign outcomes, while a larger group continue on a problematic path. A final integrative question concerns the most effective conceptualization of the disorder in relation to broader dysregulation. Key scientific priorities are noted.

Examining the Role of Genetic Risk and Longitudinal Transmission Processes Underlying Maternal Parenting and Psychopathology and Children's ADHD Symptoms and Aggression: Utilizing the Advantages of a Prospective Adoption Design

Although genetic factors may contribute to initial liability for ADHD onset, there is growing evidence of the potential importance of the rearing environment on the developmental course of ADHD symptomatology. However, associations between family-level variables (maternal hostility, maternal depressive symptoms) and child behaviors (developmental course of ADHD and aggression) may be explained by genes that are shared by biologically related parents and children. Furthermore, ADHD symptoms and aggression commonly co-occur: it is important to consider both simultaneously to have a better understanding of processes underlying the developmental course of ADHD and aggression. To addresses these issues, we employed a longitudinal genetically sensitive parent-offspring adoption design. Analyses were conducted using Cohort I (n = 340) of the Early Growth and Development Study with cross-validation analyses conducted with Cohort II (n = 178). Adoptive mother hostility, but not depression, was associated with later child ADHD symptoms and aggression. Mothers and their adopted children were genetically unrelated, removing passive rGE as a possible explanation. Early child impulsivity/activation was associated with later ADHD symptoms and aggression. Child impulsivity/activation was also associated with maternal hostility, with some evidence for evocative gene-environment correlation processes on adoptive mother depressive symptoms. This study provides novel insights into family-based environmental influences on child ADHD and aggression symptoms, independent of shared parental genetic factors, implications of which are further explicated in the discussion.

From Toddlerhood to Adolescence: Which Characteristics Among Toddlers with Autism Spectrum Disorder Predict Adolescent Attention Deficit/Hyperactivity Symptom Severity? A Long-Term Follow-Up Study

High rates of attention deficit/hyperactivity disorder (ADHD) comorbidity have been described in autism spectrum disorder (ASD). This study searched for predictors at toddlerhood of the severity of ADHD symptoms at adolescence. The study included 65 participants, (mean age = 13:8 year), diagnosed with ASD at toddlerhood. Participants underwent a comprehensive assessment of cognitive ability, adaptive skills and autism severity at toddlerhood and adolescence. More severe restricted and repetitive behaviors (RRB) in toddlerhood predicted the severity of Inattention symptoms. In addition, more severe RRB and lower adaptive skills in the toddler years significantly predicted the severity of Hyperactivity/Impulsivity symptoms. Adolescents with elevated ADHD symptoms diagnosed at toddlerhood with ASD showed lower cognitive and adaptive skills and more severe autism symptoms.

Early developmental pathways to childhood symptoms of attention-deficit hyperactivity disorder, anxiety and autism spectrum disorder

BACKGROUND

Children with autism spectrum disorder (ASD) often have co-occurring symptoms of attention-deficit/hyperactivity disorder (ADHD) and/or anxiety. It is unclear whether these disorders arise from shared or distinct developmental pathways. We explored this question by testing the specificity of early-life (infant and toddler) predictors of mid-childhood ADHD and anxiety symptoms compared to ASD symptoms.

METHODS

Infants (n = 104) at high and low familial risk for ASD took part in research assessments at 7, 14, 24 and 38 months, and 7 years of age. Symptoms of ASD, ADHD and anxiety were measured by parent report at age 7. Activity levels and inhibitory control, also measured by parent report, in infancy and toddlerhood were used as early-life predictors of ADHD symptoms. Fearfulness and shyness measured in infancy and toddlerhood were used as early-life predictors of anxiety symptoms. Correlations and path analysis models tested associations between early-life predictors and mid-childhood ADHD and anxiety symptoms compared to mid-childhood ASD symptoms, and the influence of controlling for ASD symptoms on those associations.

RESULTS

Increased activity levels and poor inhibitory control were correlated with ADHD symptoms and not ASD or anxiety; these associations were unchanged in path models controlling for risk-group and ASD symptoms. Increased fearfulness and shyness were correlated with anxiety symptoms, but also ASD symptoms. When controlling for risk-group in path analysis, the association between shyness and anxiety became nonsignificant, and when further controlling for ASD symptoms the association between fearfulness and anxiety became marginal.

CONCLUSIONS

The specificity of early-life predictors to ADHD symptoms suggests early developmental pathways to ADHD might be distinct from ASD. The overlap in early-life predictors of anxiety and ASD suggests that these disorders are difficult to differentiate early in life, which could reflect the presence of common developmental pathways or convergence in early behavioural manifestations of these disorders.

Temperament and Cognitive Regulation During the First 3 Years of Life as Predictors of Inattention and Hyperactivity/Impulsivity at 6 Years

Objective: With a wish to identify early markers of inattention and hyperactivity/impulsivity, we examined effects of temperament and cognitive regulation, during the first 3 years of life, on later inattentive and hyperactive/impulsive behavior. Method: Temperament and cognitive regulation were assessed at 12, 18, 24, and 36 months in 66 typically developing children. Teachers rated inattention and hyperactivity/impulsivity at 6 years. Results: Temperamental activity at all studied time points was predictive of later hyperactive/impulsive behavior, thus appearing as a stable marker thereof. Activity at 12 months was also predictive of inattention, whereas temperamental persistence was correlated with inattention and hyperactivity/impulsivity, but with no independent contributions. No significant relations between cognitive regulation and the outcome measures were found. Conclusion: Our findings add to the scarce literature proposing that markers of inattentive and hyperactive/impulsive behavior in early school age can be found within the first years of life, using parental ratings of child temperament.

Early life predictors of attention deficit/hyperactivity disorder symptomatology profiles from early through middle childhood

This study used repeated measures data to identify developmental profiles of elevated risk for ADHD (i.e., six or more inattentive and/or hyperactive-impulsive symptoms), with an interest in the age at which ADHD risk first emerged. Risk factors that were measured across the first 3 years of life were used to predict profile membership. Participants included 1,173 children who were drawn from the Family Life Project, an ongoing longitudinal study of children's development in low-income, nonmetropolitan communities. Four heuristic profiles of ADHD risk were identified. Approximately two thirds of children never exhibited elevated risk for ADHD. The remaining children were characterized by early childhood onset and persistent risk (5%), early childhood limited risk (10%), and middle childhood onset risk (19%). Pregnancy and delivery complications and harsh-intrusive caregiving behaviors operated as general risk for all ADHD profiles. Parental history of ADHD was uniquely predictive of early onset and persistent ADHD risk, and low primary caregiver education was uniquely predictive of early childhood limited ADHD risk. Results are discussed with respect to how changes to the age of onset criterion for ADHD in DSM5 may affect etiological research and the need for developmental models of ADHD that inform ADHD symptom persistence and desistance.

Moderation of parenting by inhibitory control in the prediction of the common and unique variance of hyperactivity-impulsivity and inattention

This study examined whether the interaction between parenting and inhibitory control predicts hyperactivity-impulsivity and inattention in 195 children. Observation data of positive parenting were collected at 4 years, and mother reports of coercive parenting at 5 years, inhibitory control at 6 years, and hyperactivity-impulsivity/inattention at 7 years were obtained. The common and unique variance of hyperactivity-impulsivity and inattention symptoms were examined as outcomes using a bifactor model. Results indicated that positive parenting practices predicted lower levels of hyperactivity-impulsivity/inattention behaviors at age 7 only when children's inhibitory control was high. These results support the vantage sensitivity model, which posits that some individuals show an increased sensitivity to positive experiences exclusively, and support the appropriateness of a targeted prevention approach in early childhood.

The Impact of Adult ADHD in the Quality of Life Profile

OBJECTIVE

In this multicenter, cross-sectional study, we aimed to investigate the quality of life (QoL) and the neuropsychological and clinical characteristics of adults with ADHD with different developmental pathways.

METHOD

Our study sample included 25 control (healthy) participants, 31 patients with newly diagnosed ADHD without comorbidities (ADHD-C-D), 31 with newly diagnosed ADHD with comorbidities (ADHD+C-D), and 29 with previously diagnosed ADHD with comorbidities (ADHD+C+D).

RESULTS

Compared with controls, ADHDs had little differences in the attentional performance but showed higher impulsivity, more severe symptoms of depression and anxiety, and lower QoL. The ADHD+C-D group showed more severe symptoms of depression and anxiety than the ADHD+C+D group ( p = .037 and p = .008, respectively), and poorer QoL in the psychological health sphere ( p = .003).

CONCLUSION

Differences between ADHD and control subjects were particularly remarkable in mood symptoms and QoL. Previous diagnosis might have a positive impact on mood symptoms and QoL in ADHD adults.

Investigation of a developmental pathway from infant anger reactivity to childhood inhibitory control and ADHD symptoms: interactive effects of early maternal caregiving

BACKGROUND

ADHD is a neurodevelopmental disorder with a complex pathogenesis. Individual differences in temperamental reactivity - in particular, anger reactivity - are predictive of ADHD. The goal of this study was to examine the moderating (maternal caregiving behaviors; MCB) and mediating (inhibitory control) variables of reactivity using a 9-year multimethod prospective longitudinal design.

METHODS

Participants included 291 children (135 male; 156 female) who participated in a larger study of temperament and social-emotional development. Anger reactivity was assessed by observation of facial anger during an arm restraint task, and MCB were observed during a series of semi-structured mother-infant tasks, both at 9 months of age. Inhibitory control was assessed by performance on a go/no-go task at 5 years of age. ADHD symptoms were assessed by parent and teacher report questionnaires at 7 and 9 years, respectively.

RESULTS

Anger reactivity and poor inhibitory control were predictive of later ADHD symptoms. Results supported a moderated mediation model, in which the indirect effects of anger reactivity on ADHD symptoms through inhibitory control were conditional on quality of early MCB. Inhibitory control mediated the effect of anger reactivity on ADHD symptoms, but only among children exposed to lower-quality MCB.

CONCLUSIONS

Infant anger reactivity exerts a direct effect on later ADHD from infancy, suggesting anger reactivity as a very early indicator of ADHD risk. Higher-quality caregiving did not buffer against the direct risk of anger reactivity on ADHD but did buffer against the indirect risk by reducing the negative effect of anger reactivity on inhibitory control. Thus, in the developmental pathway from anger reactivity to ADHD, more sensitive, less intrusive parenting supports the development of protective mechanisms (i.e. inhibitory control) to remediate ADHD risk.

Predicting ADHD Symptoms in Adolescence from Early Childhood Temperament Traits

Extreme levels of certain temperament traits can be early markers of different developmental pathways of attention-deficit/hyperactivity disorder (ADHD). However, the long-term utility of using these traits as predictors of ADHD is not fully known. This study includes 64 male adolescents (M age = 13.5), who have been followed since birth as part of a longitudinal study. The primary aim was to test effortful control (EC), activity level, and anger, measured in early childhood - both with mother's reports and laboratory assessments -as predictors of ADHD symptoms in adolescence. Further, we investigated the specificity of this prediction to the different ADHD symptom domains. The results demonstrated that early temperament dimensions of EC and activity level were predictive of ADHD symptoms about 10 years later, when the participants reached adolescence. Moreover, activity level showed specificity only to hyperactivity-impulsivity symptoms whereas EC was a predictor of the two symptom domains. Anger had a predictive correlation with ADHD symptoms; however, it did not have a unique predictive contribution. These results emphasize the relevance of EC and activity level in the developmental course of ADHD. Identification of early risk factors can lead to more efficient design and implementation of intervention programs.

Infant temperament reactivity and early maternal caregiving: independent and interactive links to later childhood attention-deficit/hyperactivity disorder symptoms

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with origins early in life. There is growing evidence that individual differences in temperament reactivity are predictive of ADHD symptoms, yet little is known about the relations between temperament reactivity in early infancy and later ADHD symptoms or the combined effect of reactivity with early environmental factors on ADHD symptom development. Using a 9-year prospective longitudinal design, this study tested the independent and interactive contributions of infant reactivity and maternal caregiving behaviors (MCB) on parent- and teacher-reported childhood ADHD symptoms.

METHODS

Participants included 291 children (135 male; 156 female) who participated in a larger study of temperament and social-emotional development. Reactivity was assessed by behavioral observation of negative affect, positive affect, and motor activity during novel stimuli presentations at 4 months of age. MCB were observed during a series of semistructured mother-infant tasks at 9 months of age. Finally, ADHD symptoms were assessed by parent- and teacher-report questionnaires at 7 and 9 years, respectively.

RESULTS

Reactivity was predictive of ADHD symptoms, but results were sex specific. For boys, infant motor activity was positively predictive of later ADHD symptoms, but only at lower quality MCB. For girls, infant positive affect was positively predictive of later ADHD symptoms at lower quality MCB, and-unexpectedly-infant positive affect and motor activity were negatively predictive of later ADHD symptoms at higher quality MCB.

CONCLUSIONS

These results point to early parenting as a moderating factor to mitigate temperament-related risk for later ADHD, suggesting this as a potential intervention target to mitigate risk for ADHD among reactive infants.

Early Detection of ADHD: Insights From Infant Siblings of Children With Autism

Converging evidence suggests shared genetic underpinnings of attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Studies of infants at risk for ASD have proliferated over the past decade; the few studies that have followed these infants beyond age 3 report a range of difficulties facing a subset of these infants as they reach school age, including elevated levels of attention problems and externalizing behavior. Given this, we aimed to identify early predictors of school-age ADHD outcomes in a sample of infant siblings at risk for ASD. This study reports on a sample of 59 infants at high and low risk for ASD who had been followed for more than a decade, collecting data at regular intervals from 3 to 36 months and then determining diagnostic outcome at 8-10 years of age. Seventeen participants were diagnosed with Diagnostic and Statistical Manual of Mental Disorders (5th ed.) ADHD at school age (n = 14 high risk, 3 low risk). As infants, the ADHD outcome group demonstrated atypical longitudinal patterns of sustained visual attention. A significantly larger proportion of their parents reported behavior/temperament problems at 36 months of age, and examiners noted the presence of inattentive, hyperactive, and/or impulsive behaviors in this group by 18 months of age. These data suggest that behavioral indicators of risk for later ADHD may be present early in development, which may improve earlier detection and treatment of the disorder.

Prenatal phthalate exposures and child temperament at 12 and 24 months

INTRODUCTION

Gestational phthalate exposures have been adversely associated with attention, externalizing, and internalizing behaviors in childhood. Early childhood temperament may be a marker of later behavioral patterns. We therefore sought to determine whether gestational phthalate exposures were associated with infant and toddler temperament.

METHODS

The Mount Sinai Children's Environmental Health Study is a prospective cohort study of children born between May 1998 and July 2001 in New York City (N=404). Phthalate metabolites were measured in spot urine samples collected from pregnant women in their third trimester. Child temperament was assessed by parental report at 12-months using the Infant Behavior Questionnaire (IBQ) (N=204) and at 24-months using the Toddler Behavior Assessment Questionnaire (TBAQ) (N=279). We used multiple linear regression to evaluate associations between urinary phthalate metabolites and eleven temperament domains.

RESULTS

Phthalate biomarker concentrations were weakly associated with lower gross motor activity levels as well as higher duration of orienting at the 12-month assessment. Mono(3-carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP) and the sum of metabolites of di(2-ethylhexyl) phthalate (∑DEHP) were associated with lower levels of smiling and laughing at 12 months. At 24-months, social fear and lower pleasure was linked to higher concentrations of MCPP and MBzP, and higher ∑DEHP was weakly associated with increased anger levels at 24-months.

CONCLUSIONS

Though we observed some weak associations between biomarkers of prenatal exposure to phthalates and temperament at 12- and 24-months, overall phthalates biomarkers were not strongly associated with alterations in temperament.