Eight-Year Latent Class Trajectories of Academic and Social Functioning in Children with Attention-Deficit/Hyperactivity Disorder

We examined trajectories of academic and social functioning in children with attention-deficit/hyperactivity disorder (ADHD) to identify those who might be at risk for especially severe levels of academic and social impairment over time. We estimated a series of growth mixture models using data from two subsamples of children participating in the NIMH Collaborative Multisite Multimodal Treatment Study of Children with ADHD (MTA) including those with at least baseline and 96-month data for reading and mathematics achievement (n = 392; 77.3% male; M age = 7.7; SD = 0.8) or social skills ratings from teachers (n = 259; 74.9% male; M age = 7.6; SD = 0.8). We compared latent trajectories for children with ADHD to mean observed trajectories obtained from a local normative (i.e., non-ADHD) comparison group (n = 289; 80.6% male; M age = 9.9; SD = 1.1). Results indicated six latent trajectory classes for reading and mathematics and four classes for teacher social skills ratings. There was not only a relationship between trajectories of inattention symptoms and academic impairment, but also a similarly strong association between trajectory classes of hyperactive-impulsive symptoms and achievement. Trajectory class membership correlated with socio-demographic and diagnostic characteristics, inattention and hyperactive-impulsive symptom trajectories, externalizing behavior in school, and treatment receipt and dosage. Although children with ADHD display substantial heterogeneity in their reading, math, and social skills growth trajectories, those with behavioral and socio-demographic disadvantages are especially likely to display severe levels of academic and social impairment over time. Evidence-based early screening and intervention that directly address academic and social impairments in elementary school-aged children with ADHD are warranted. The ClinicalTrials.gov identifier is NCT00000388.     

Smaller splenium in children with nonverbal learning disability compared to controls,high-functioning autism and ADHD

The current study investigated morphological differences in the corpus callosum in children ages 8 to 18 years old with nonverbal learning disability (NLD; n = 19), high-functioning autism (HFA; n = 23), predominantly inattentive ADHD (ADHD:PI; n = 23), and combined type ADHD (ADHD:C; n = 25), as well as those demonstrating typical development (n = 57). Midsagittal area of the corpus callosum and five midsagittal anterior-to-posterior corpus callosum segments were examined using magnetic resonance imaging. Controlling for midsagittal brain area and age, no group differences were found for total corpus callosum area. This finding indicates that higher functioning children on the autistic spectrum do not have smaller corpus callosi as has been found in previous research with heterogeneous samples. Following segmentation of the corpus callosum, the NLD group was observed to have significantly smaller splenia compared to all other groups. Smaller splenia in the NLD group was associated with lower WASI PIQ scores but not WASI VIQ scores. Children with HFA were observed to have larger midbody areas than children with NLD and neurotypically developing children. Children with HFA and NLD demonstrated behavioral symptoms of inattention and hyperactivity similar to the ADHD groups indicating that corpus callosum differences seen in the NLD and HFA groups are not related to these behaviors.     

Timed performance weaknesses on computerized tasks in pediatric brain tumor survivors: A comparison with sibling controls

With more children surviving a brain tumor, insight into the late effects of the disease and treatment is of high importance. This study focused on profiling the neurocognitive functions that might be affected after treatment for a pediatric brain tumor, using a broad battery of computerized tests. Predictors that may influence neurocognitive functioning were also investigated. A total of 82 pediatric brain tumor survivors (PBTSs) aged 8–18 years (M = 13.85, SD = 3.15, 49% males) with parent-reported neurocognitive complaints were compared to a control group of 43 siblings (age M = 14.27, SD = 2.44, 40% males) using linear mixed models. Neurocognitive performance was assessed using measures of attention, processing speed, memory, executive functioning, visuomotor integration (VMI), and intelligence. Tumor type, treatment, tumor location, hydrocephalus, gender, age at diagnosis, and time since diagnosis were entered into regression analyzes as predictors for neurocognitive functioning. The PBTSs showed slower processing speeds and lower intelligence (range effect sizes .71–.82, p < .001), as well as deficits in executive attention, short-term memory, executive functioning, and VMI (range effect sizes .40–.57, p < .05). Older age at assessment was associated with better neurocognitive functioning (B = .450, p < .001) and younger age at diagnosis was associated with lower intelligence (B = .328, p < .05). Medical risk factors, e.g., hydrocephalus, did not show an association with neurocognitive functioning. Late effects in PBTSs include a broad range of neurocognitive deficits. The results suggest that even PBTSs that were traditionally viewed as low risk for neurocognitive problems (e.g., surgery only, no hydrocephalus) may suffer from decreased neurocognitive functioning.     

Clinical and functional correlates of processing speed in pediatric Attention-Deficit/Hyperactivity Disorder: a systematic review and meta-analysis

It is well established that processing speed is negatively impacted in children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD). Unfortunately, exactly how processing speed vulnerabilities manifest in daily functioning has not been well established. To support clinical care of youth with ADHD, it is important to better understand the functional consequences and relevant outcomes associated with processing speed deficits. This systematic review and meta-analysis sought to identify the association between processing speed and clinical or functional correlates among children or adolescents diagnosed with ADHD. A total of 409 abstracts were screened, of which, 60 full-text articles were identified as potentially relevant, and 8 of these studies met inclusion criteria. Domains evaluated across these studies included reading skills, mathematics skills, written expression, anxiety, self-appraisals of competence, and adaptive functioning. Six studies reported an association between processing speed and reading skills, allowing for meta-analysis. Processing speed difficulties among youth with ADHD appear strongly associated with several clinical and functional correlates including weaker academic skills, poorer adaptive skills, increased self-reported anxiety, and overestimates of social competence. Meta-analytic results for studies reporting the association between processing speed and reading skills indicate a medium overall weighted mean effect size (r = 0.33, 95% CI = 0.28 –0.39) with minimal heterogeneity (I² = 0.17). Clinical implications of these findings, limitations in the current knowledge base, and suggestions for future research are discussed.     

Brief report: Neurocognitive functioning in adolescents following childhood maltreatment and evidence for underlying planning & organizational deficits

Children and adolescents with a history of childhood maltreatment are at risk for a host of psychiatric conditions, although the underlying neurocognitive functioning of these individuals remains largely understudied. This study examined the neurocognitive functioning of childhood maltreatment victims in an adolescent psychiatric inpatient setting. The sample consisted of adolescent inpatients (ages 13–19) that completed intellectual testing as part of a neuropsychological/psychological assessment during hospitalization (n = 39). The sample was grouped based on childhood maltreatment history with one group categorized by maltreatment history (n = 15) and the other group characterized by no maltreatment history (n = 24). Analyses revealed statistically significant differences (p < .01) between maltreatment groups on the majority of assessed domains. When controlling for intelligence, only performance differences on the RCFT remained. RCFT differences remained after controlling for the influence of visual-motor and visual-perceptual/visual-spatial functioning, highlighting the influence of organizational and planning difficulties in those individuals with maltreatment history. Group differences in the frequency of impaired performance for neuropsychological tasks were largest (p < .001) for FSIQ and RCFT. Compromised neurocognitive functioning may negatively contribute to the clinical presentation of this population, highlighting the importance of the child neuropsychologist in the effective treatment of children and adolescents with a history of childhood maltreatment.     

Associations Between Family Environment, Parenting Practices, and Executive Functioning of Children with and Without ADHD

We examined the relationships between executive functioning, family environment, and parenting practices in children diagnosed with ADHD as compared to children without ADHD. Participants were parents (N = 134) of 6- to 12-year-old ADHD and non-ADHD-diagnosed children. Compared to the control group, parents of children diagnosed with ADHD reported their children as exhibiting greater problems with behavioral control and metacognitive abilities, and described their family environments as less organized and higher in family conflict. Family environment and parenting practices were not correlated with behavioral control or metacognitive abilities in children with ADHD. In children without ADHD, higher levels of family cohesion, organization, and expressiveness, and lower levels of family conflict, were significantly correlated with greater behavioral control. Higher levels of family cohesion and organization were significantly and positively associated with regulation of metacognitive abilities in children without ADHD. In general, aspects of the family environment and parental limit setting appear to be associated with the development of executive functions in children not diagnosed with ADHD; however, family environment and parenting practices were not associated with executive functions in children diagnosed with ADHD.     

Social Cognition and Interpersonal Impairment in Young Adolescents with ADHD

The purpose of this study is twofold. First, it aims to examine whether the impairment in peer functioning and social-cognitive deficits (i.e., hostile attribution bias, social comprehension, social problem-solving) found in elementary school aged children with ADHD also occur in adolescence. Second, it aims to provide evidence for a predictive relationship between these social-cognitive deficits and an adolescent’s functional impairment in the social domain. To address these aims, several social-cognitive tasks were administered to a small sample of young adolescents with ADHD (N = 27) and a comparison sample without an ADHD diagnosis (N = 18). Parent report of functional impairment and peer sociometric data were also gathered. Comparisons of both parent and peer report of adolescent social functioning suggest that individuals with ADHD continue to experience difficulties with peers into the adolescent years and data from the social-cognitive tasks show evidence of social comprehension and problem-solving deficits. Further analyses indicated a significant link between functional impairment and social cognition. Findings herein are discussed in the context of both the developmental changes that arise during adolescence and consideration of the importance of social cognition for understanding the impaired social functioning experienced by adolescents with ADHD.     

Performance-based and parent ratings of attention in children treated for a brain tumor: The significance of radiation therapy and tumor location on outcome

Children are at increased risk for cognitive difficulties following the diagnosis and treatment of a brain tumor. Radiation therapy (RT) and tumor location are commonly-cited predictors of neurocognitive functioning. Disruptions to foundational neurocognitive processes such as attention, working memory, and processing speed underlie declines on measures of general intellectual functioning. While several studies have examined visual sustained attention in pediatric brain tumor patients, auditory sustained attention has yet to be examined. This study employs a longitudinal design to examine performance-based and parent ratings of attention in children undergoing surgical resection of a brain tumor (n = 29) and treated with (n = 11) or without (n = 18) RT at 6.79 months post-surgery (baseline) and then again at 30.56 months post-surgery (follow-up). The measures include an auditory continuous performance test (CPT) and parent ratings of attention and hyperactivity on a behavior rating scale. Ultimately, children treated with and without RT performed similarly on performance-based and parent ratings of attention. However, the performance on the auditory CPT differed according to tumor location, with children with infratentorial tumors committing more inattention and inhibitory control errors compared to children with supratentorial tumors. Parent ratings did not differ according to tumor location, and parent ratings and auditory sustained attention performance are not significantly correlated. The findings are interpreted in the context of neurocognitive and brain development.     

Clinical,Sociobiological, and Cognitive Predictors of ADHD Persistence in Children Followed Prospectively Over Time

With increasing awareness that ADHD is chronically disabling, a burgeoning literature has examined childhood clinical indicators of ADHD persistence. This study investigates whether childhood factors reflecting biological risk and cognitive reserve have additive predictive value for the persistence of ADHD that is unique beyond childhood indicators of disorder severity. One-hundred thirty children with ADHD (mean age = 8.9 years, 75 % male) were followed into adolescence (mean age = 14.0 years). Childhood ADHD and co-morbidities were assessed via interviews with parents and teachers; parental psychopathology was assessed via parent interview; exposure to neurobiological and psychosocial adversity were indexed by parent questionnaire; and cognitive reserve was evaluated through children’s performance on measures of IQ and executive functioning. Univariate analyses identified childhood inattention and hyperactivity-impulsivity, co-morbid oppositional defiant disorder, overall impairment, and paternal anxiety and depression as more prevalent amongst adolescents with persistent compared with remitted ADHD. Only child-level predictors remained significant in a final multivariate model. These results suggest that children who are most likely to experience persistent ADHD have a more severe clinical presentation in childhood, reflected by increased levels of inattention, oppositional behavior, and impairment. They also are more likely to have fathers with internalizing concerns, but these concerns do not uniquely predict ADHD persistence beyond child-level factors. Contrary to expectations, childhood adversity and cognitive functioning did not predict the course of ADHD.     

Naming speed as a predictive diagnostic measure in reading and attentional problems

This study aimed to describe and compare naming speed abilities in children diagnosed with either Reading Learning Difficulties (RLD) or Attention Deficit/Hyperactivity Disorder (ADHD), or comorbidity for both (ADHD+RLD). To examine the explanatory power of naming speed and ADHD symptomatology in predicting group associations (while controlling for gender and age), the “Rapid Automatized Naming and Rapid Alternating Stimulus Tests” (RAN/RAS) were utilized. A sample of 101 children (age range = 5–16 years) was divided into four groups: RLD (n = 14), ADHD (n = 28), comorbid (n = 19), and control (n = 40). There were statistically significant differences in RAN/RAS results among the diagnostic groups. Moreover, discriminant analysis revealed that naming speed tasks significantly predicted reading and attentional problems, especially at earlier ages. These results demonstrate the potential usefulness of RAN/RAS in the diagnosis of reading and attentional problems, particularly if the children are aged from 5 to 9.     

A rating measure of ADHD-related neuropsychological impairment in children and adolescents: Data from the Cognition and Motivation in Everyday Life (CAMEL) Scale from population and clinical samples

A new parent-completed questionnaire, the Cognition and Motivation in Everyday Life (CAMEL) scale, was developed to provide a comprehensive assessment of neuropsychological impairment in children related to attention-deficit/hyperactivity disorder (ADHD) across diverse cognitive, motivational and energetic domains. Its psychometric properties were investigated. A total of 60 items were generated to cover a wide range of putative ADHD-related neuropsychological processes. A clinical (n = 142) and community (n = 810) sample of parents with children between 6 and 16 years of age completed the questionnaire. Data on ADHD symptoms were also collected with a commonly-used, validated parent rating scale to explore the associations between CAMEL scores and dimensional measures of child ADHD and conduct problems. Factor analysis identified six factors which we labeled (i) Cognition, (ii) Self-Direction and Organization, (iii) Effort Engagement, (iv) Arousal Regulation, (v) Motivational Responsiveness, and (vi) Cautiousness. Self-Direction and Organization and Arousal Regulation were the strongest predictors for ADHD symptomatology. Self-Direction and Organization was strongly associated with inattention and Arousal Regulation with hyperactivity-impulsivity symptoms. Parents distinguished between broad neuropsychological domains in reliable and plausible ways, making distinctions between key aspects of functioning. However, the boundaries between these domains did not map directly onto the distinctions drawn within traditional models of ADHD deficits. Further research is required to examine the predictive validity and cost-effectiveness of the CAMEL scale compared to direct objective testing using laboratory measures in predicting prognosis and treatment outcome.     

Test of visuospatial construction: Validity evidence in extremely low birth weight and late preterm children at early school age

The Test of Visuospatial Construction (TVSC), a measure of visuoconstruction that does not rely on upper extremity motor response or written production, was administered to extremely low birth weight (ELBW), late preterm (LPT), and term participants at preschool (n = 355) and kindergarten (n = 265) ages. TVSC showed statistically significant weak-to-moderate positive correlations (age 3: r = .118–.303; age 6: r = .138–.348) with Developmental VMI, Differential Ability Scales-II Copying, Matrices, and Pattern Construction subtests, Baron-Hopkins Board Test, and the Purdue Pegboard. One-way ANOVA indicated ELBW performed worse than Term (p = .044) on visuospatial construction at age 3 with a small-to-medium effect size (d = ?0.43). No other statistically significant differences were found at age 3 on the TVSC (ELBW/LPT: p = .608, d = ?0.17; LPT/Term: p = .116, d = ?0.31). At age 6, ELBW participants performed worse than LPT participants (p = .027) and Term participants (p = .012); LPT participants did not differ from Term participants. Small effect sizes at age 3 (ELBW < LPT, d = ?0.17; ELBW < Term, d = ?0.43) were notably larger at age 6 (ELBW < LPT, d = ?0.42; ELBW < Term, d = ?0.53). Important practical differences showing LPT participants performed below Term participants (d = ?0.31) at age 3 were no longer evident at age 6 (d = ?0.097). These findings provide preliminary evidence of TVSC validity supporting its use to detect neuropsychological impairment and to recommend appropriate interventions in young preterm children.     

Parent and Family Characteristics and Their Associates in a Follow-Up of Outpatient Children with ADHD

We examined associations between child symptoms, demographic variables, parent and family characteristics in a long-term follow-up study of 214 outpatient children with attention-deficit/hyperactivity disorder (ADHD). The children’s mean age was 12.6 (SD = 2.1) years, and the mean interval from diagnosis to follow-up was 3.7 (SD = 2.2) years. We compared the characteristics of the clinical group with a community group (n = 110) recruited from the same catchment area. Parents filled out questionnaires on child symptoms, parent characteristics, and family functioning. The results showed that parents of young boys (<13 years) experienced more parenting stressors than those of adolescent boys (≥13 years), but the opposite was true for parents of girls. Parents of children with both ADHD and oppositional defiant disorder symptoms in the clinical range experienced significantly more parent and family dysfunctions than those of children with ADHD only (even after controlling for levels of ADHD symptoms in the child). Parents of children in the community group experienced significantly less parent and family dysfunctions than those of children with ADHD. Partial correlations between parent characteristics and child symptoms showed that oppositional symptoms were most strongly associated with parent and family dysfunction. Fathers experienced significantly less parenting stress, parental efficacy, and child involvement than mothers. We conclude that parents of children with ADHD experienced considerable strain related to a broad range of parent and family characteristics. Assessment of such characteristics should be part of routine assessment procedures and a prerequisite for family-focused treatment of children with ADHD.     

Expressed Emotion,Parental Stress,and Family Dysfunction Among Parents of Nonclinical Italian Children

Expressed emotion (EE) is an index of the amount of emotion typically displayed by a family member or caretaker characterized by high emotional involvement, hostility or criticism. The aims of the current study were (a) to examine EE, stress and helplessness in childcare, and family functioning in mothers and fathers of elementary and junior high school children without clinical mental health problems living in a “nonclinical” family context; (b) to assess relationships between child age, gender, socio-economic status and EE; and (c) to investigate whether there are some factors—in a “normal family” context—that play a crucial role in the quality of EE. EE, assessed using the Five Minute Speech Sample (FMSS), and questionnaires assessing parenting alliance, family functioning, parenting stress index, and the parent’s state of helplessness in caring for the child were completed by a community-based Italian sample of mothers and fathers of children (N = 381) aged 6–14 years (M = 9.8, SD = 2.25). As expected, low rates in all FMSS variables were found for mothers and fathers, without significant differences between them. Mothers and fathers who showed high EE scores reported higher family non-adaptive functioning. Mothers also reported higher parental stress and higher Helplessness in caring for the child. Mothers’ stress and fathers’ reports of higher family non-adaptive functioning were the most consistent predictors of EE. Further research is needed to highlight associations between EE and family functioning.     

Improving Outcomes for Youth with ADHD: A Conceptual Framework for Combined Neurocognitive and Skill-Based Treatment Approaches

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent and chronic mental health condition that often results in substantial impairments throughout life. Although evidence-based pharmacological and psychosocial treatments exist for ADHD, effects of these treatments are acute, do not typically generalize into non-treated settings, rarely sustain over time, and insufficiently affect key areas of functional impairment (i.e., family, social, and academic functioning) and executive functioning. The limitations of current evidence-based treatments may be due to the inability of these treatments to address underlying neurocognitive deficits that are related to the symptoms of ADHD and associated areas of functional impairment. Although efforts have been made to directly target the underlying neurocognitive deficits of ADHD, extant neurocognitive interventions have shown limited efficacy, possibly due to misspecification of training targets and inadequate potency. We argue herein that despite these limitations, next-generation neurocognitive training programs that more precisely and potently target neurocognitive deficits may lead to optimal outcomes when used in combination with specific skill-based psychosocial treatments for ADHD. We discuss the rationale for such a combined treatment approach, prominent examples of this combined treatment approach for other mental health disorders, and potential combined treatment approaches for pediatric ADHD. Finally, we conclude with directions for future research necessary to develop a combined neurocognitive + skill-based treatment for youth with ADHD.     

Poorer divided attention in children born very preterm can be explained by difficulty with each component task,not the executive requirement to dual-task

Children born very preterm (VP, ≤ 32 weeks) exhibit poor performance on tasks of executive functioning. However, it is largely unknown whether this reflects the cumulative impact of non-executive deficits or a separable impairment in executive-level abilities. A dual-task paradigm was used in the current study to differentiate the executive processes involved in performing two simple attention tasks simultaneously. The executive-level contribution to performance was indexed by the within-subject cost incurred to single-task performance under dual-task conditions, termed dual-task cost. The participants included 77 VP children (mean age: 7.17 years) and 74 peer controls (mean age: 7.16 years) who completed Sky Search (selective attention), Score (sustained attention) and Sky Search DT (divided attention) from the Test of Everyday Attention for Children. The divided-attention task requires the simultaneous performance of the selective- and sustained-attention tasks. The VP group exhibited poorer performance on the selective- and divided-attention tasks, and showed a strong trend toward poorer performance on the sustained-attention task. However, there were no significant group differences in dual-task cost. These results suggest a cumulative impact of vulnerable lower-level cognitive processes on dual-tasking or divided attention in VP children, and fail to support the hypothesis that VP children show a separable impairment in executive-level abilities.     

Executive Functioning Characteristics Associated with ADHD Comorbidity in Adolescents with Disruptive Behavior Disorders

The nature of executive dysfunction in youth with disruptive behavior disorders (DBD) remains unclear, despite extensive research in samples of children with attention-deficit hyperactivity disorder (ADHD). To determine the relationship between DBD, ADHD, and executive function deficits in aggressive teens, adolescents with DBD and comorbid ADHD (DBD + ADHD; n = 25), DBD without ADHD (DBD-ADHD; n = 23), and healthy controls (HC; n = 25) were compared on neurocognitive tests and questionnaires measuring executive functioning. Teens with DBD + ADHD performed worse on both neurocognitive and questionnaire measures of executive function than the DBD-ADHD and HC groups. Results suggest that subgroups of DBD may exist depending on the presence or absence of comorbid ADHD, which may have implications for the selection and efficacy of treatment strategies.     

Attention and executive functioning profiles in children following perinatal arterial ischemic stroke

Perinatal arterial ischemic stroke (PAIS) is a form of childhood stroke; the majority of those affected experience neurologic sequelae, including motor, language and neurocognitive impairments. This study examines the attention and executive functioning (EF) profiles of children following PAIS, as well as the impact of age and sex. In this single-center cross-sectional study, 40 children aged 3 to 16 years (median age 7.2 years; 58% male) who have suffered a PAIS underwent a comprehensive neuropsychological battery to assess attention and EF. Parents completed behavioral questionnaires regarding real-world functioning. Composite scores were calculated for seven attention and EF domains (Attention, Working Memory, Verbal Retrieval, Inhibitory Control, Flexibility/Shifting, Planning/Organization, and Processing Speed). The results for all measured domains of attention and EF are significantly lower in the participants compared to the normative samples (p < .001), with the exception of Working Memory. However, increasing difficulty with Working Memory is associated with developing age. Older age at time of testing is also associated with a higher incidence of clinically-elevated attention deficit hyperactivity disorder (ADHD) symptoms. Sex is not associated with performance measures or parental report of functioning. The participants demonstrate mild-to-moderate attention and EF impairment compared to the normative population. Clinicians, families, and educators should be informed about the neurocognitive sequelae of PAIS and the need for close developmental surveillance in this population to identify vulnerable children and initiate appropriate therapeutic interventions in a timely fashion.     

Early motor development and cognitive abilities among Mexican preschoolers

Psychomotricity plays a very important role in children’s development, especially for learning involving reading–writing and mathematical calculations. Evaluate motor development in children 3 years old and its relationship with their cognitive abilities at the age of 5 years. Based on a cohort study, we analyzed the information about motor performance evaluated at 3 years old by Peabody Motor Scale and cognitive abilities at 5 years old. The association was estimated using linear regression models adjusted by mother’s intelligence quotient, sex, Bayley mental development index at 18 months, and quality of the environment at home (HOME scale). 148 children whose motor performance was determined at age 3 and was evaluated later at age 5 to determine their cognitive abilities. Cognitive abilities (verbal, quantitative, and memory) measured by McCarthy Scales. Significant positive associations were observed between stationary balance at age 3 with verbal abilities (β = 0.67, p = .04) and memory (β = 0.81, p = .02) at 5 years. Grasping and visual-motor integration were significant and positively associated with quantitative abilities (β = 0.74, p = .005; β = 0.61, p = .01) and memory (β = 2.11, p = .001; β = 1.74, p = .004). The results suggest that early motor performance contributes to the establishment of cognitive abilities at 5 years. Evaluation and early motor stimulation before the child is faced with formal learning likely helps to create neuronal networks that facilitate the acquisition of academic knowledge.     

Sluggish Cognitive Tempo Symptoms Contribute to Heterogeneity in Adult Attention-Deficit Hyperactivity Disorder

Attention-deficit hyperactivity disorder (ADHD) persists into adulthood in over 50% of cases, although its associated symptom profiles, comorbid problems, and neuropsychological deficits change substantially across development. Sluggish cognitive tempo (SCT) symptoms may contribute to associations between ADHD and comorbid problems and may partially explain the substantial heterogeneity observed in its correlates. 349 adults aged 18–38 years (M = 23.2, SD = 4.5, 54.7% male, 61.03% with ADHD) completed a multi-informant diagnostic procedure and a comprehensive neuropsychological battery. Adults with ADHD (n = 213) were retained for analyses. Latent class analyses (LCA) revealed three profiles of SCT symptoms among those with ADHD, which we classified as minimal, moderate, or severe SCT. Multiple analysis of covariance (MANCOVA) revealed significant differences among these profiles, which remained when controlling for persistence of ADHD symptoms and sex. In general, adults with ADHD combined with SCT symptoms (moderate and severe) had significantly more symptoms of anxiety, depression, and persistent inattention, and had more severe professional and relational impairment compared to ADHD adults without SCT. Compared to those with moderate or minimal SCT symptoms, the severe SCT group had the most symptoms of depression and internalizing disorders, and the most impairment in the domain of daily responsibility. No significant differences based on externalizing symptoms emerged when controlling for sex and persistence of inattention symptoms, suggesting the moderate and severe SCT groups do not simply reflect more symptoms. Moreover, follow-up mediation analyses revealed that SCT might at least partially explain the heterogeneity in ADHD. Findings have implications for refinement of etiological conceptualization, assessment methods, and intervention strategies.