Identifying Early Markers of "Late Onset" Attention Deficit and Hyperactivity/Impulsivity Symptoms

Late adolescent outcomes of different developmental trajectories of ADHD symptoms in a large longitudinal study

There exists substantial heterogeneity in the developmental trajectories of ADHD symptoms, with distinctions often made between persistent versus remittent, and early- versus late-onset. However, how these trajectories relate to late adolescent functioning and whether, in particular, later onset trajectories mark a milder subtype remains unclear. Building on earlier work that has examined early life predictors of ADHD symptom trajectories up to age 14, we applied latent class growth analysis to data from the UK Millennium Cohort Study (N = 10,262) to evaluate whether developmental trajectories of ADHD symptoms up to age 17 (from age 3) were similar to those identified up to age 14 and associated with differing levels of impairment in peer victimisation, mental health, substance use, and delinquency outcomes at age 17. Our optimal model included five trajectory groups, labelled unaffected (37.6%), mildly affected (34.8%), subclinical remitting (14.4%), adolescent onset (7.6%), and stable high (5.6%). Adolescent onset and stable high trajectories were similarly impaired across all outcomes, other than substance use. Subclinical remitting individuals were impaired on self-esteem and well-being compared to unaffected individuals. By the end of mid-adolescence, those with a later onset have similar impairments to those following an early onset/persistent trajectory. Residual impairment may remain for those on a remitting trajectory.

The neural and genetic underpinnings of different developmental trajectories of Attention-Deficit/Hyperactivity Symptoms in children and adolescents

BACKGROUND

The trajectory of attention-deficit hyperactivity disorder (ADHD) symptoms in children and adolescents, encompassing descending, stable, and ascending patterns, delineates their ADHD status as remission, persistence or late onset. However, the neural and genetic underpinnings governing the trajectory of ADHD remain inadequately elucidated.

METHODS

In this study, we employed neuroimaging techniques, behavioral assessments, and genetic analyses on a cohort of 487 children aged 6-15 from the Children School Functions and Brain Development project at baseline and two follow-up tests for 1 year each (interval 1: 1.14 ± 0.32 years; interval 2: 1.14 ± 0.30 years). We applied a Latent class mixed model (LCMM) to identify the developmental trajectory of ADHD symptoms in children and adolescents, while investigating the neural correlates through gray matter volume (GMV) analysis and exploring the genetic underpinnings using polygenic risk scores (PRS).

RESULTS

This study identified three distinct trajectories (ascending-high, stable-low, and descending-medium) of ADHD symptoms from childhood through adolescence. Utilizing the linear mixed-effects (LME) model, we discovered that attention hub regions served as the neural basis for these three developmental trajectories. These regions encompassed the left anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC), responsible for inhibitory control; the right inferior parietal lobule (IPL), which facilitated conscious focus on exogenous stimuli; and the bilateral middle frontal gyrus/precentral gyrus (MFG/PCG), accountable for regulating both dorsal and ventral attention networks while playing a crucial role in flexible modulation of endogenous and extrinsic attention. Furthermore, our findings revealed that individuals in the ascending-high group exhibited the highest PRS for ADHD, followed by those in the descending-medium group, with individuals in the stable-low group displaying the lowest PRS. Notably, both ascending-high and descending-medium groups had significantly higher PRS compared to the stable-low group.

CONCLUSIONS

The developmental trajectory of ADHD symptoms in the general population throughout childhood and adolescence can be reliably classified into ascending-high, stable-low, and descending-medium groups. The bilateral MFG/PCG, left ACC/mPFC, and right IPL may serve as crucial brain regions involved in attention processing, potentially determining these trajectories. Furthermore, the ascending-high pattern of ADHD symptoms exhibited the highest PRS for ADHD.

Substance use in sexual minority youth: prevalence in an urban cohort

BACKGROUND

Little comparative data on substance use (SU) between sexual minority youth (SMY) and heterosexual youth (HET) is available. This study compares the prevalence of SU in an urban cohort between SMY and HET and evaluates demographic and psychosocial predictors of SU.

METHODS

Data came from a prospective-longitudinal cohort study in an urban setting (N = 1297). SU and psychosocial variables such as internalizing symptoms, self-control, sensation-seeking, bullying-victimization, subjective stress, leisure activities, and peer influences were assessed with self-reports at age 17 and 20. SU was stratified by sex and sexual attraction, and the groups were compared using regression models, with demographic and psychosocial variables included as covariates.

RESULTS

SMY- and HET-youth displayed differences in a number of psychosocial variables. Overall, SMY- and HET-youth differed in their 12-months prevalence of SU: At age 17, SMY-females had significantly higher rates of SU than HET-females for cannabis (aOR = 2.14, p = 0.04), ecstasy/MDMA (aOR = 4.29, p = 0.01), and hallucinogens (aOR = 5.59, p = 0.02). At age 20, SMY-females had significantly higher rates of SU than HET-females for tobacco (aOR = 2.06, p = 0.03), cannabis (aOR = 2.24, p = 0.004), ecstasy/MDMA (aOR = 3.93, p < 0.001), stimulants (aOR = 3.45, p = 0.002), and hallucinogens (aOR = 6.65, p < 0.001). SMY-males reported significantly lower rates for tobacco and cannabis than HET-males at age 17. At age 20, they reported significantly higher rates for the use of ecstasy/MDMA (aOR = 2.30, p = 0.04) and hallucinogens (aOR = 2.43, p = 0.03).

CONCLUSIONS

Given that psychosocial variables were significant covariates of SMY-status and SU, our results underline the importance of accounting for these when explaining differences in SU between adolescents. While differentiation by sex is established in most studies, such standardized comparisons are lacking with regards to sexual identities. But knowledge about SU of SMY is critical for designing effective interventions. This is especially true for SMY-females: Thus, SU in SMY-females early in life needs to be explored more thoroughly and addressed with adequate prevention measures.

Young Adulthood Outcomes of Joint Mental Health Trajectories: A Group-Based Trajectory Model Analysis of a 13-Year Longitudinal Cohort Study

Developmental trajectories of common mental health issues such as ADHD symptoms, internalising problems, and externalising problems can often be usefully summarised in terms of a small number of 'developmental subtypes' (e.g., 'childhood onset', 'adolescent onset') that may differ in their profiles or levels of clinically meaningful variables such as etiological risk factors. However, given the strong tendency for symptoms in these domains to co-occur, it is important to consider not only developmental subtypes in each domain individually, but also the joint developmental subtypes defined by symptoms trajectories in all three domains together (e.g., 'late onset multimorbid', 'pure internalising', 'early onset multimorbid'). Previous research has illuminated the joint developmental subtypes of ADHD symptoms, internalising problems, and externalising problems that emerge from normative longitudinal data using methods such as group-based trajectory modelling, as well as predictors of membership in these developmental subtypes. However, information on the long-term outcomes of developmental subtype membership is critical to illuminate the likely nature and intensity of support needs required for individuals whose trajectories fit different developmental subtypes. We, therefore, evaluated the relations between developmental subtypes previously derived using group-based trajectory modelling in the z-proso study (n = 1620 with trajectory data at ages 7, 8, 9, 10, 11, 12, 13, 15) and early adulthood outcomes. Individuals with multimorbid trajectories but not 'pure' internalising problem elevations showed higher levels of social exclusion and delinquency at age 20. These associations held irrespective of the specific developmental course of symptoms (e.g., early versus late onset versus remitting). There was also some evidence that intimate partner violence acts as a form of heterotypic continuity for earlier externalising problems. Results underline the need for early intervention to address the pathways that lead to social exclusion and delinquency among young people with multiple co-occurring mental health issues.

Polysubstance Use in Early Adulthood: Patterns and Developmental Precursors in an Urban Cohort

Polysubstance use (i.e., simultaneous or sequential use of different psychoactive substances) is associated with increases in the risk of severe health problems and social impairments. The present study leverages community-representative, long-term longitudinal data from an urban cohort to assess: (a) the prevalence and continuation of polysubstance use between adolescence and early adulthood; (b) different patterns of polysubstance use (i.e., combinations of substances) in early adulthood; and (c) childhood risk factors for polysubstance use in early adulthood. At age 20 (n = 1,180), respondents provided comprehensive self-reported information on past-year substance use, including use of legal and illicit substances (e.g., cannabinoids, stimulants, and hallucinogens), and nonmedical use of prescription drugs (e.g., opioids, tranquilizers). In adolescence (ages 13–17), limited versions of this questionnaire were administered. In childhood (ages 7–11), potential risk factors, including individual-level factors (e.g., sensation-seeking, low self-control, aggression, and internalizing symptoms) and social-environmental factors (e.g., social stressors, exposure to others’ substance use), were assessed. We fitted latent class models to identify classes of participants with different substance use profiles in early adulthood. The results show that polysubstance use increased between early adolescence and early adulthood. The continuation of polysubstance use was common (stability between all adjacent assessments: odds ratio >7). At age 20, more than one-third of participants reported polysubstance use (involving illicit substances, nonmedical use of prescription drugs, and cannabidiol). Four latent classes with polysubstance use were identified: (1) broad spectrum of substances; (2) cannabis and club drugs; (3) cannabis and the nonmedical use of prescription drugs; and (4) different cannabinoids. Risk factors for any polysubstance use included childhood sensation-seeking and exposure to others’ substance use; some childhood risk factors were differentially associated with the four classes (e.g., low self-control in childhood was associated with an increased likelihood of being in the broad spectrum class). The classes also differed with regard to socio-demographic factors. This study revealed that polysubstance use is a widespread and multifaceted phenomenon that typically emerges during adolescence. To facilitate the design of tailored prevention mechanisms, the heterogeneity of polysubstance use and respective socio-demographic and developmental precursors need to be considered.

Cohort Profile: The Zurich Project on the Social Development from Childhood to Adulthood (z-proso)

The Zurich Project on the Social Development from Childhood to Adulthood (z-proso) began in 2004 in response to the need for a better evidence base to support optimal child social development and prevent crime and violence. Since then, the study has tracked the development of a diverse sample of youths (N = 1,675 in the target sample; ~50% female) from age 7 (n = 1,360) to age 20 (n = 1,180), with primary data collection waves at ages 7, 8, 9, 10, 11, 12, 13, 15, 17, and 20. The study uses a multi-method, multi-informant design that combines teacher, youth, and parent reports with observational and behavioural measures, biosampling, functional imaging, and ecological momentary assessment. Analyses of the data have contributed important evidence to a diversity of topics in child and adolescent development, illuminating the developmental roots of crime and aggression, the impacts of exposure to different forms and combinations of victimisation, and trajectories of mental health and neurodevelopmental symptoms.

A multi-trajectory analysis of commonly co-occurring mental health issues across childhood and adolescence

Developmental trajectories of mental health issues can often be usefully summarised in a small number of clinically meaningful subtypes. Given the high levels of heterotypic and homotypic comorbidity in child and adolescent mental health symptoms, we explored whether it was possible to identify clinically meaningful developmental subtypes of multiple commonly co-occurring mental health issues. We evaluated the combined developmental trajectories of the most common and commonly co-occurring child and adolescent mental health issues: attention-deficit/hyperactivity disorder (ADHD), internalising, and externalising symptoms in a normative sample of youth with data (n = 1620) at ages 7, 8, 9, 10, 11, 12, 13 and 15 using group-based multi-trajectory modelling. Multinomial logistic regression was used to evaluate predictors of group membership. Our optimal model included six trajectory groups, labelled 'unaffected', 'normative maturing', 'internalising', 'multimorbid late onset', 'multimorbid remitting', and 'multimorbid with remitting externalising'. Examining covariates of group membership suggested that males and bully victims tend to have complex mental health profiles; academic achievement and smoking during pregnancy have general associations with mental health irrespective of symptom developmental trajectories or combination; and maternal post-natal depression is primarily related to symptoms that are already in evidence by the beginning of the school years. Results suggest that developmental trajectories of commonly co-occurring mental health issues can be usefully summarised in terms of a small number of developmental subtypes. These subtypes more often than not involve multiple co-occurring mental health issues. Their association with mental health covariates depends on the combination and developmental timing of symptoms in ways that suggest they can be clinically informative.

A Longitudinal and Gender Invariance Analysis of the Strengths and Difficulties Questionnaire Across Ages 3, 5, 7, 11, 14, and 17 in a Large U.K.-Representative Sample

Developmental invariance is important for making valid inferences about child development from longitudinal data; however, it is rarely tested. We evaluated developmental and gender invariance for one of the most widely used measures of child mental health: the parent-reported Strengths and Difficulties Questionnaire (SDQ). Using data from the large U.K. population-representative Millennium Cohort Study (N = 10,207; with data at ages 3, 5, 7, 11, 14, and 17 years), we tested configural, metric, scalar, and residual invariance in emotional problems, conduct problems, hyperactivity/inattention, prosociality, and peer problems. We found that the SDQ showed poor fit at age 3 in both males and females and at age 17 in males; however, it fit reasonably well and its scores were measurement invariant up to the residual level across gender at ages 5, 7, 11, and 14 years. Scores were also longitudinally measurement invariant across this age range up to the partial residual level. Results suggest that the parent-reported SDQ can be used to estimate developmental trajectories of emotional problems, conduct problems, hyperactivity/inattention, prosociality, and peer problems and their gender differences across the age range 5 to 14 years using a latent model. Developmental differences outside of this range may; however, partly reflect measurement differences.

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.

Neurocognitive markers of late-onset ADHD: a 6-year longitudinal study

BACKGROUND

There is an increased interest in 'late-onset' attention-deficit/hyperactivity disorder (ADHD), referring to the onset of clinically significant ADHD symptoms after the age of 12 years. This study aimed to examine whether unaffected siblings with late-onset ADHD could be differentiated from stable unaffected siblings by their neurocognitive functioning in childhood.

METHODS

We report findings from a 6-year prospective, longitudinal study of the Dutch part of the International Multicenter ADHD Genetics (IMAGE) study, including individuals with childhood-onset (persistent) ADHD (n = 193), their siblings with late-onset ADHD (n = 34), their stable unaffected siblings (n = 111) and healthy controls (n = 186). At study entry (mean age: 11.3) and follow-up (mean age: 17.01), participants were assessed for ADHD by structured psychiatric interviews and multi-informant questionnaires. Several neurocognitive functions were assessed at baseline and after 6 years, including time reproduction, timing variability (reaction time variability and time production variability), reaction time speed, motor control and working memory; intelligence was taken as a measure of overall neurocognitive functioning.

RESULTS

Siblings with late-onset ADHD were similar to individuals with childhood-onset ADHD in showing longer reaction times and/or higher error rates on all neurocognitive measures at baseline and follow-up, when compared to healthy controls. They differed from stable unaffected siblings (who were similar to healthy controls) by greater reaction time variability and timing production variability at baseline. No significant group by time interaction was found for any of the tasks.

CONCLUSIONS

For unaffected siblings of individuals with ADHD, reaction time variability and timing production variability may serve as neurocognitive marker for late-onset ADHD.

Metacognitive and motivation deficits, exposure to trauma, and high parental demands characterize adolescents with late-onset ADHD

The objective of this study is to evaluate support for three hypotheses about the etiology of adolescent-onset ADHD symptoms: (1) a "cool" cognitive load hypothesis, (2) a "hot" rewards processing hypothesis, and (3) a trauma exposure hypothesis. Participants (N = 50) were drawn from two public high schools in a culturally diverse metropolitan area. A detailed procedure for identifying and confirming late-onset ADHD cases is described. Adolescents with late-onset ADHD (n = 15) were identified and compared to childhood-onset (n = 17) and non-ADHD classmates (n = 18). Adolescents and parents completed measures of neurocognition, rewards' processing, clinical profile, and environmental demands. Late-onset cases were clinically and neurocognitively indistinguishable from childhood-onset cases; however, they experienced higher demands from parents (d = 1.09). Compared to the non-ADHD group, late-onset cases showed significant deficits in metacognition (d = 1.25) and academic motivation (d = 0.80), as well as a pronounced history of multiple trauma exposure (OR 11.82). At 1-year follow-up, ADHD persisted in 67.7% of late-onset cases. Late-onset cases (26.7%) were more likely than childhood-onset cases (0.0%) to transfer to alternative schools by 1-year follow-up. Multiple factors may contribute to adolescent-onset ADHD. Adolescents with metacognition and motivation deficits may be at greatest risk for the late-onset ADHD phenotype, particularly in highly demanding environments. Exposure to traumatic stress may play a key role in the exacerbation of existing deficits or onset of new symptoms. Late-onset ADHD was persistent in most cases and associated with higher risk for school disengagement than childhood-onset ADHD. Further work is needed to better understand the etiologies of late-onset ADHD symptoms.

Outcomes of ADHD Symptoms in Late Adolescence: Are Developmental Subtypes Important?

Objective: Substantial individual variation exists in the age of onset and course of ADHD symptoms over development. We evaluated whether, within this variation, meaningful developmental subtypes can be defined. Method: Using growth mixture modeling in a community-based sample (N = 1,571), we analyzed ADHD symptom trajectories based on measures taken at ages 7, 8, 9, 10, 11, 13, and 15 years. We evaluated whether those showing developmental trajectories characterized by later onsets versus early onsets differed in terms of mental health and behavioral outcomes in late adolescence (age 17 years). Result: The late onset category was best conceptualized as a milder subtype than early onset. The former was, however, more similar in outcomes to the latter than to the unaffected category, suggesting that later onsets are still associated with impairment. Conclusion: Considering diagnoses for those affected by ADHD symptoms but who do not meet current age of onset criteria may be important for ensuring that they receive appropriate support.

Should We Subtype ADHD According to the Context in Which Symptoms Occur? Criterion Validity of Recognising Context-Based ADHD Presentations

ADHD symptoms show considerable individual variation in the contexts in which they are expressed. It has previously been proposed that subtyping individuals according to the contexts in which symptoms are expressed may be clinically useful. We examined context-based patterns of ADHD symptoms in a longitudinal cohort study of n = 1388 children, as well as context-specific and context-general predictors of symptoms. Participants were community-ascertained and provided ADHD symptom data at ages 7, 9, and 11. Using growth mixture modelling we identified five inattention and five hyperactivity/impulsivity categories that differed in the developmental patterns of symptoms reported by parent and teacher informants. We found some evidence that context-specific predictors were related to context-specific expressions. Specifically, after controlling for other risk factors for ADHD symptoms, relationships with teachers predicted school-specific (teacher-reported) but not home-specific (parent-reported) symptom levels. However, no subtypes defined by exclusively home-based symptoms emerged, suggesting that while symptoms may sometimes be specific to the school context, they are only rarely confined to the home context. Subtyping by context could be informative; however, further work will required to uncover the nature of any etiological, functional, or outcome differences between those who show symptom expression in different contexts.

Increased risk of ADHD in families with ASD

Attention Deficit and Hyperactive Disorder (ADHD) and Autism Spectrum Disorders (ASD) are frequent comorbid neurodevelopmental conditions and the overlap between both disorders remains to be delineated. A more complete understanding of the shared genetic and environmental factors is needed. Using a family-based method, we evaluated the risk of ADHD in a group of relatives with an ASD proband (ASD-) and a group of relatives with an ASD and ADHD proband (ASD+). We enrolled 1245 individuals in the study: 499 probands, their 746 first-degree relatives and 140 controls. We used a multivariate generalized estimating equation (GEE) model, in which the dependent variable was the ADHD diagnosis in the relatives and the independent variable the ASD+ or ASD- in probands. We adjusted for sociodemographic factors (age, sex, IQ) and for the nature of the familial relationship with the affected proband (parent or sibling). Among the probands, there were 287 ASD- and 212 ASD+ individuals. ADHD was more frequent in relatives (19%) than in the control group (7%) (p = 0.001). The risk of ADHD was higher in the ASD+ relatives group than in the ASD- relatives group (GEE model OR 1.58 [95% CI 1.04-2.38], p = 0.032). This result was found in parents (OR 1.96 [95% CI  1.14-3.36], but not in siblings (OR 1.28 [95% CI 0.84-1.94], p = 0.434). Our study provides a representative estimate of the family distribution of ADHD in relatives of ASD probands but supports the modest effect of shared genetic and environmental factors between both disorders.

Disagreeing about development: An analysis of parent-teacher agreement in ADHD symptom trajectories across the elementary school years

OBJECTIVES

It is well-known that in cross-sectional analyses, agreement between informants is modest as best when rating attention-deficit/hyperactivity disorder and other disruptive behaviour disorder symptoms. We here aimed to develop recommendations for the use of multi-informant data in the context of longitudinal developmental analyses that examine symptom trajectories over time.

METHOD

Using parallel process modelling, we estimated parent-teacher agreement in inattention and hyperactivity/impulsivity symptom initial levels and slopes across the elementary school years (ages 7, 9, and 11) for a community sample of n = 1,388 youth. We also used these models to examine whether initial levels and slopes differed significantly across informants.

RESULTS

Informant agreement was low to moderate and higher for inattention slopes (r = .47) than for hyperactivity/impulsivity slopes (r = .23). Parents and teachers reported opposite developmental trends for inattention with teachers reporting declines and parents reporting increases over time. Parents reported overall higher levels of hyperactivity/impulsivity, but there were no average informant differences in slopes.

CONCLUSION

Of the options available, we recommend specifying separate but correlated factors for different informants in developmental analyses of attention-deficit/hyperactivity disorder. This can be achieved within latent growth curve and growth mixture models.

Evaluating Longitudinal Invariance in Dimensions of Mental Health Across Adolescence: An Analysis of the Social Behavior Questionnaire

Measurement invariance over time (longitudinal invariance) is a core but seldom-tested assumption of many longitudinal studies on adolescent psychosocial development. In this study, we evaluated the longitudinal invariance of a brief measure of adolescent mental health: the Social Behavior Questionnaire (SBQ). The SBQ was administered to participants of the Zurich Project on the Social Development of Children and Youths in up to four waves spanning ages 11 to 17. Using a confirmatory factor analysis approach, metric invariance held for all constructs, but there were some violations of scalar and strict invariance. Overall, intercepts tended to increase over time while residual variances decreased. This suggests that participants may become more willing or able to identify and report on certain behaviors over time. The noninvariance was not practically significant in magnitude, except for the Anxiety dimension where artifactual increases over development would be liable to occur if invariance is not appropriately modeled. Overall, results support the utility of the SBQ as an omnibus measure of psychosocial health across adolescence.