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

Association between relative age at school and persistence of ADHD in prospective studies: an individual participant data meta-analysis

BACKGROUND

The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.

METHODS

For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to "cohort" and "ADHD" with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650.

FINDINGS

Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99-1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years.

INTERPRETATION

The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further.

FUNDING

None.

A Cross-Sectional Study to Measure Physical Activity with Accelerometry in ADHD Children according to Presentations

(1) Background: Attention deficit hyperactivity disorder (ADHD) is a common mental disorder affecting 5-7% of school-aged children. Previous studies have looked at the effects of physical activity interventions on the symptoms of ADHD, although few have compared the motor behavior of children with ADHD versus those without. This exploratory study provides detailed information on the patterns and intensity of physical activity and sedentary behavior in children with ADHD as measured by Actigraph GT3X accelerometry, as well as the differences in physical activity in the different presentations of ADHD; (2) Methods: A cross-sectional design was used with a sample of 75 children, aged 6 to 12 years, with and without ADHD. The ADHD group had a previous diagnosis, determined by clinical assessment based on DSM-5 criteria; (3) Results: Physical activity levels were higher in children with ADHD compared to children without ADHD, but there was no difference in sedentary time between groups during weekdays or weekends. Physical activity decreased with age, with significant differences in the ADHD group, who exhibited more minutes of moderate Physical activity in 6-7 year-olds than 10-11 year-olds during weekdays and weekends; (4) Conclusions: Sedentary time increased by age in children without ADHD, and there was a decrease in moderate-intensity physical activity time in children with ADHD by age.

Physical activity and the development of general mental health problems or attention-deficit hyperactivity disorder (ADHD) symptoms in children and adolescents: A cross-lagged panel analysis of long-term follow-up epidemiological data

Studies have shown that physical activity (PA) can provide a helpful, low-risk, and cost-effective intervention for children and adolescents suffering from mental health problems. This longitudinal study aimed to assess whether PA prevents the development of mental health problems, such as attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. Data were analyzed from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) collected from more than 15.000 children and adolescents at three different time points over a period of more than 10 years. Parents scored the PA of the study participants on three frequency levels according to WHO recommendations, and mental health problems were assessed by means of the Strengths and Difficulties Questionnaire (SDQ). The total problem score (SDQ-Total) and the hyperactivity/inattention symptoms sub-scale (SDQ-H/I) were used in an autoregressive cross-lagged model to examine their relationship with PA. The results showed that PA of boys and girls at preschool age was inversely associated with the occurrence of mental health problems and, in particular, ADHD symptoms about 6 years later. Higher levels of PA were associated with better general mental health and fewer ADHD symptoms at the next time point (Wave 1). These effects were not observed from preadolescence (Wave 1) to adolescence (Wave 2), neither for girls nor for boys. These findings indicate that medium-to-high PA may be a supportive factor for good mental health in children in preschool and elementary school. Future studies will have to show whether PA may be a helpful add-on for interventional programs for improving general mental health and alleviating ADHD symptoms among children and adolescents.

Measuring children's behavioral regulation in the preschool classroom: An objective, sensor-based approach

Children's abilities to regulate their behaviors are critical for learning and development, yet researchers lack an objective, precise method for assessing children's behavioral regulation in their everyday environments such as their classrooms. This study tested a sensor-based approach to assess preschool children's behavioral regulation objectively, precisely, and naturalistically. Children wore accelerometer devices as they engaged in center-based play in their preschool classrooms for roughly 45 min (N = 50 children, 48% female, mean age = 4.5 years). Set to record data each second, these devices collected information about children's movement (N = 140,564 observations). From these data, the authors extracted concrete behaviors hypothesized to index behavioral regulation and compared them with teacher and observer ratings of the same. Initiating movement more frequently, staying seated in activities for shorter amounts of time, and spending a greater amount of time in motion were related to lower ratings of attention and inhibitory control by teachers and by observers of classroom group time, median r = .45, p < .01. These same objectively measured behaviors showed only weak associations with children's performance on assessments of cognitive regulation, median r = .11, p = .47. The findings indicate that ambulatory accelerometers can capture movement-based indicators of children's behavioral regulation in the classroom setting and that performance on measures of cognitive regulation does not strongly predict children's behavior in the classroom. As an unobtrusive and objective measure, actigraphy may become an important tool for studying children's behavioral regulation in everyday contexts.

Inattention and hyperactivity symptoms in childhood predict physical activity in adolescence

BACKGROUND

Physical activity has been documented to influence several aspects of physical and mental health. Growing evidence shows that physical activity can improve attention. Less is known about how symptoms of inattention and hyperactivity / impulsivity in childhood are associated with physical activity in adolescence. We aimed to explore this relationship further.

METHODS

We used a cohort of 3949 Swedish children (1884 boys and 2065 girls) with data collected at ages 9 (or 12) and 15. We investigated the influence of symptoms of inattention and hyperactivity / impulsivity in childhood - age 9/12 (inattention and hyperactivity/impulsivity separately) on self-rated physical activity at age 15, using multiple logistic regression models. We considered potential confounders such as sex, parental education level, physical activity in childhood and neurodevelopmental comorbidity. A cluster robust sandwich estimator was applied to adjust the standard errors for the nested twin data when computing the regression models.

RESULTS

Symptoms of inattention in childhood (9/12) predicted less physical activity in adolescence (age 15) (OR = 0.83 CI = 0.78-0.89), whereas the opposite was true for hyperactivity/impulsivity (OR = 1.08 CI = 1.02-1.10). These associations still remained when taking possible confounders into account including neurodevelopmental and neurodevelopmental related comorbidity.

CONCLUSIONS

These findings support the importance of helping children and adolescents with inattention symptoms to engage in physical activity in suitable settings.

Actigraph-Measured Movement Correlates of Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms in Young People with Tuberous Sclerosis Complex (TSC) with and without Intellectual Disability and Autism Spectrum Disorder (ASD)

Actigraphy, an objective measure of motor activity, reliably indexes increased movement levels in attention-deficit/hyperactivity disorder (ADHD) and may be useful for diagnosis and treatment-monitoring. However, actigraphy has not been examined in complex neurodevelopmental conditions. This study used actigraphy to objectively measure movement levels in individuals with a complex neurodevelopmental genetic disorder, tuberous sclerosis (TSC). Thirty participants with TSC (11–21 years, 20 females, IQ = 35–108) underwent brief (approximately 1 h) daytime actigraph assessment during two settings: movie viewing and cognitive testing. Multiple linear regressions were used to test associations between movement measurements and parent-rated ADHD symptoms. Correlations were used to examine associations between actigraph measures and parent-rated ADHD symptoms and other characteristics of TSC (symptoms of autism spectrum disorder (ASD), intellectual ability (IQ), epilepsy severity, cortical tuber count). Higher movement levels during movies were associated with higher parent-rated ADHD symptoms. Higher ADHD symptoms and actigraph-measured movement levels during movies were positively associated with ASD symptoms and negatively associated with IQ. Inter-individual variability of movement during movies was not associated with parent-rated hyperactivity or IQ but was negatively associated with ASD symptoms. There were no associations with tuber count or epilepsy. Our findings suggest that actigraph-measured movement provides a useful correlate of ADHD in TSC.