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

Abstract

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 = À.28, CI = À0.42, À0.12, 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.

Using the Infant Sibling-Design to Explore Associations Between Autism and ADHD Traits in Probands and Temperament in the Younger Siblings

“…While our study only found modest associations between activity level and ADHD traits across siblings, previous research indicate that activity level plays an important role in the development of ADHD (Kostyrka-Allchorne et al, 2020;Nigg, 2006). A recent meta-analysis found that higher activity levels in infants and toddlers predicted later ADHD traits and diagnosis, even after controlling for other aspects of temperament such as negative emotionality and effortful control (Joseph et al, 2023). Our findings align with recent research demonstrating a consistent predictive relationship between high activity level in infants and later ADHD.…”

Genetic and phenotypic evidence of the predictive validity of preschool parent reports of hyperactivity/impulsivity and inattention

“…Monitoring is the key word: while individual preschool time-points, starting at age 1.5 years for HI and 4 years for IN, predict the high trajectory outcomes, regression models show that each subsequent time-point adds to the prediction. These results are also consistent with studies showing that HI in toddlers, and possibly earlier, is more predictive as a dimension of ADHD than IN (Joseph et al, 2023). Overall, the phenotypic results suggest that timely monitoring is needed to assess risk more reliably than single screening assessments and that parents of preschoolers provide valuable information in that respect.…”

Exploring the impact of antenatal micronutrients used as a treatment for maternal depression on infant temperament in the first year of life

“…This emphasizes the combination between biology and environment: an individual's temperament is genetically influenced and thus relatively stable; however, it is still shaped by the environment individuals develop in and interact with over time. Infant temperament has been positively associated with later social competence (10), identified as a risk factor in the development of future psychopathology including ADHD (11) and externalizing/ internalizing behavioral problems (e.g., anxiety, depression) (12), and is often considered the building blocks of adult personality (13). Given this understanding of how temperament originates and its impact on long term development, it is not surprising the connection among temperament, fetal programming, and antenatal depression is being increasingly explored.…”