A Longitudinal Twin Study on the Association Between Inattentive and Hyperactive-Impulsive ADHD Symptoms

DSM-IV distinguishes two symptom domains of attention deficit hyperactivity disorder (ADHD): inattentiveness and hyperactivity-impulsivity. The present study examines the aetiologies and developmental relations underlying the associations between inattentiveness and hyperactivity-impulsivity over time, based on a representative population sample from the United Kingdom of approximately 7,000 twin pairs. ADHD symptoms were assessed as continuous dimensions using the DSM-IV items from the Conners’ Parent Rating Scale at two ages: middle childhood (age 1) and early adolescence (age 2). Quantitative genetic cross-lagged analyses showed that the association of the ADHD dimensions over time is influenced by stable as well as newly developing genetic factors. Moreover the longitudinal relationship between the ADHD dimensions appears to be unidirectional, with hyperactivity-impulsivity in middle childhood predicting the presence of inattentiveness in early adolescence, but not vice versa. Thus, hyperactivity-impulsivity may serve to exacerbate inattentiveness over time. Findings are discussed in the context of developmental changes in ADHD symptoms.     

Attention-deficit/hyperactivity disorder: perspectives from neuroimaging

Attention-deficit/hyperactivity disorder (ADHD) is a common childhood behavioral disorder most often characterized by inattentiveness, impulsivity, and hyperactivity. Current etiologic theories suggest that ADHD stems from abnormalities in dopaminergic and possibly noradrenergic brainstem nuclei that act to regulate a cortico-striato-thalamo-cortical network, believed to be critical for executive functions and the regulation of behavioral responses such as arousal, attention, and inhibition. Noninvasive structural and functional neuroimaging techniques provide a new avenue for exploring the validity of these theories. Despite their limitations, neuroimaging studies have provided a unique and otherwise inaccessible, biological perspective of ADHD. Collectively, the studies reviewed here reveal that dysfunction in arousal, behavioral inhibition, and attention associated with ADHD may result from structural abnormalities in frontostriatal regions that in turn result in diminished activity essential for normal function.     

Sluggish Cognitive Tempo (Concentration Deficit Disorder?): Current Status, Future Directions, and a Plea to Change the Name

Symptoms of sluggish cognitive tempo (SCT) have been recognized for nearly 30 years as comprising a semi-independent set(s) of symptoms from the inattentive (IN) and hyperactive-impulsive (HI) symptoms involved in attention-deficit/hyperactivity disorder (ADHD). It has only been within the past decade that research focusing specifically on SCT symptoms and on samples of SCT cases chosen independently from ADHD samples has increased so as to address the question of whether SCT is a distinct condition from ADHD or other disorders. All but two of these studies have focused on children but the two extant large scale studies on adults have replicated those findings. This Commentary highlights not only those findings concerning SCT that appear to be relatively robust, but also those patterns that appear to be emerging yet in need of further research to corroborate their association with SCT, as well as those barely or unexplored areas that may deserve more research. Evidence to date, including the many findings in this special issue, is nearing a critical mass that likely supports the conclusion that SCT is a distinct disorder of attention from ADHD, yet one that may overlap with it in about half of all cases. SCT has unique symptom dimensions and comorbidities from ADHD, probably distinct though lesser domains of impairment and demographic correlates, and perhaps unique cognitive deficits, causes and life course risks. These latter areas, however, are in need of substantially more research as is SCT in adults and treatments specifically designed for cases of SCT. Meanwhile, the name of the condition is premature, implying a known cognitive deficit that is as yet unknown, and is proving derogatory and offensive to patients, leading this author to recommend a change to Concentration Deficit Disorder.     

Adult ADHD and/or Sleep Apnea? Differential Diagnostic Considerations with Six Case Studies

An increased interest in the persistence of attention-deficit hyperactivity disorder (ADHD) into adulthood brings concern that adult ADHD may become overdiagnosed. As with ADHD in childhood, various other adult psychological and medical disorders may be associated with ADHD in adulthood, and these related disorders may be mislabeled and mistreated as simple ADHD. One such medical condition is sleep apnea. This paper reviews similarities and differences between ADHD and sleep apnea and presents case histories of six adult patients diagnosed with ADHD who were subsequently found to have at least comorbid obstructive sleep apnea (OSA). Clinicians who diagnose and treat patients with ADHD are advised to become familiar with sleep apnea as a life-threatening condition that presents with overlapping symptoms.     

Symptoms of attention‐deficit/hyperactivity disorder in first‐time expectant women: Relations with parenting cognitions and behaviors

The relationship between maternal symptoms of attention‐deficit/hyperactivity disorder (ADHD) and parenting cognitions and behaviors was studied in 86 first‐time expectant women. Women high on ADHD symptoms were less likely to be married, less likely to have obtained at least some university education, and less likely to report that they wanted to get pregnant at the time they became pregnant. As predicted, ADHD symptoms were positively correlated with symptoms of anxiety and depression, and predicted less positive prenatal expectations regarding the infant and the future maternal role and lower maternal self‐efficacy. Contrary to predictions, ADHD did not predict any incremental variance in maternal stressful life events or social support. Symptoms of ADHD were negatively correlated with attendance at recommended prenatal checkups, but were unrelated to other behaviors during pregnancy. Findings suggest that even prior to any contact with their infant, women with ADHD symptoms have maladaptive cognitions regarding their expectations of motherhood and parenting abilities. As a result, they may benefit from early interventions that focus on attenuating the potential negative effects that these maladaptive cognitions might have on the mother‐infant relationship and later developmental outcomes for their children.     

Adults With Attention‐Deficit/Hyperactivity Disorder: Assessment and Treatment Strategies

Attention‐deficit/hyperactivity disorder (ADHD) among adults is characterized by inattentiveness and impulsivity. This article provides counselors with information about the etiology, assessment, and treatment of adult ADHD. The identification of the genetic and neurological features of ADHD has led to improvements in evaluation and treatment. Assessment of ADHD requires knowledge of the defining characteristics, subtypes, comorbid features, and functional aspects of ADHD. Effective treatments include both medical management and counseling to address psychosocial deficits.     

A Comparison of the Neuropsychological Profiles of the DSM-IV Subtypes of ADHD

Recent research on the DSM-IV subtypes of attention-deficit/hyperactivity disorder (ADHD) has demonstrated that the subtypes differ in demographic characteristics, types of functional impairment, and profiles of comorbidity with other childhood disorders. However, little research has tested whether the subtypes differ in underlying neuropsychological deficits. This study compared the neuropsychological profiles of children without ADHD (n = 82) and children who met symptom criteria for DSM-IV Predominantly Inattentive subtype (ADHD-IA; n = 67), Predominantly Hyperactive Impulsive subtype (ADHD-HI; n = 14), and Combined subtype (ADHD-C; n = 33) in the areas of processing speed, vigilance, and inhibition. We hypothesized that children with elevations of inattention symptoms (ADHD-IA and ADHD-C) would be impaired on measures of vigilance and processing speed, whereas children with significant hyperactivity/impulsivity (ADHD-HI and ADHD-C) would be impaired on measures of inhibition. Contrary to prediction, symptoms of inattention best predicted performance on all dependent measures, and ADHD-IA and ADHD-C children had similar profiles of impairment. In contrast, children with ADHD-HI were not significantly impaired on any dependent measures once subclinical symptoms of inattention were controlled. Our results do not support distinct neuropsychological deficits in ADHD-IA and ADHD-C children, and suggest that symptoms of inattention, rather than symptoms of hyperactivity/impulsivity, are associated with neuropsychological impairment.     

Prevalence of ADHD and its subtypes in male and female adult prison inmates

There are few published studies of attention-deficit/hyperactivity disorder (ADHD) in adult inmates, and even fewer studies that have considered ADHD in adult inmates by gender. The present study examined the prevalence of ADHD, its subtypes, and associated psychological and neuropsychological comorbidity as a function of gender in a sample of 3,962 inmates (3,439 men and 523 women; mean age = 33.6 years, range 17-73) who had completed the 250-item, self-report, Diagnostic and Statistical Manual of Mental Disorders, 4th edition (Text Revision) (DSM-IV-TR)-aligned Coolidge Correctional Inventory (CCI). The overall ADHD prevalence rate found was 10.5%, which is substantially higher than the rate among adults in the general population (2-5%). The female inmate ADHD prevalence rate (15.1%) was higher than the male inmate ADHD rate (9.8%), consistent with some previous studies. The most prevalent ADHD subtype for both genders was the hyperactive-impulsive subtype. The combined and inattentive ADHD subtypes had higher levels of comorbid psychopathology than the hyperactive-impulsive ADHD subtype. As the presence of ADHD and associated gender differentials may impact the success of rehabilitation and educative programs with inmates, the assessment of ADHD and comorbid psychopathology should be a priority in initial inmate screening and evaluation.     

Adult ADHD: Associations with Personality and Other Psychopathology

The goals of this study were to explicate adult ADHD’s relations with personality at both the domain and facet levels and to examine its associations with other psychological symptoms. Community members (N?=?294) completed measures assessing ADHD inattentive and hyperactive/impulsive symptoms, five-factor model personality domains and facets, and other internalizing and externalizing symptoms. Inattentiveness showed strong negative relations with conscientiousness and extraversion and strong positive relations with neuroticism; in contrast, hyperactivity/impulsivity related negatively to agreeableness, positively to extraversion, and weakly to neuroticism. Whereas inattentiveness emerged as a positive predictor of internalizing psychopathology—and depression in particular—hyperactivity/impulsivity related weakly to internalizing but more strongly to externalizing psychopathology. Thus, inattentive and hyperactive/impulsive symptoms showed differential relations with personality—at both the domain and facet levels—and with other psychological symptoms. These results demonstrate the value in examining ADHD’s relations with personality facets and with a wide range of psychopathology within the same study.     

Five Frameworks for Increasing Understanding and Effective Treatment of Attention‐Deficit/Hyperactivity Disorder: Predominately Inattentive Type

The article presents 5 interrelated frameworks for counselors seeking to obtain a greater understanding of factors that play a pivotal role in attention‐deficit/hyperactivity disorder (ADHD). Special attention is devoted to cases in which the predominant characteristic is inattentiveness. The 5 frameworks examined are organicity, internalizing dimension, co‐occurring conditions, personality structure, and neurocounseling. Generating new perspectives for counseling practitioners should optimize counseling or treatment outcomes for clients with this multifaceted disorder.     

Are sluggish cognitive tempo symptoms associated with executive functioning in preschoolers?

The aim of this study is to investigate whether sluggish cognitive tempo (SCT) symptoms are associated with neurocognitive task performance and ratings of real-world executive functioning (EF) in preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD). The associations between parent- and teacher-rated SCT symptoms and neuropsychological task performance and ratings of EF in 61 4-year-old preschool children (51 boys, 10 girls) with self-regulation difficulties were examined, with regression analyses controlling for the effects of ADHD inattention symptoms. In the study sample, higher teacher-rated SCT symptoms are significantly associated with poorer performance on tasks of visual-perceptual abilities, auditory and visual attention, sustained and selective attention, inhibitory control, pre-numerical/numerical concepts, and slower processing speed, but SCT symptoms are not significantly associated with working memory, attention shifting or cognitive flexibility when controlling for ADHD inattention. Higher parent-rated SCT symptoms are significantly associated with visual-perceptual abilities. ADHD inattention symptoms are more strongly associated than SCT with daily life EF ratings; neither parent- nor teacher-rated SCT symptoms are significantly associated with daily life ratings of inhibition, working memory, or planning/organization after controlling for ADHD inattention. This study suggests that SCT symptoms contribute to EF deficits at least on neurocognitive tasks assessing visual-perceptual/spatial abilities, attention to detail and processing speed, as observed in this sample of young children at risk for ADHD, and may be an important intervention target.     

Confirming the Factor Structure of Attention Deficit Hyperactivity Disorder Symptoms in Adult, Nonclinical Samples

Three separate models have been proposed to describe the factor structure of attention deficit hyperactivity disorder (ADHD) in the past 20 years. The Diagnostic and Statistical Manual of Mental Disorders-III (DSM-III, 1980) proposed 3 separate factors of inattention, hyperactivity, and impulsivity. The DSM-III-R (1987) proposed a single factor. The DSM-IV (1994) described the disorder as having 2 factors: hyperactivity/impulsivity and inattention. The following 2 studies employed confirmatory factor analysis to compare each of these models and 3 alternative models. University students completed questionnaires that assessed each of the 18 symptoms listed in the DSM-IV for ADHD. The 3-factor model fit the data significantly better than each of the other models in both studies. These findings suggest that a 3-factor model of inattention, hyperactivity, and impulsivity describes adult ADHD symptoms better than current alternatives.     

Co-occurring disorders: a possible key to visual perceptual deficits in children with developmental coordination disorder?

A study was conducted to examine how visual perceptual functioning in children with DCD may be influenced by co-occurring learning problems such as reading disabilities (RD) and/or attention deficit hyperactivity disorder (ADHD). Participants included seven groups of children: 27 children with DCD only, 11 with ADHD only, 14 with RD only, 63 with DCD and at least one other disorder (i.e., DCD + ADHD, DCD + RD, DCD + ADHD + RD), and 73 typically developing controls. Visual perceptual skills were assessed using the Test of Visual Perceptual Skills (TVPS) and the Rey Osterreith Complex Figure (ROCF; copy and delayed recall). Children with DCD and at least one other disorder were found to have impairments on the TVPS compared to children with DCD only, ADHD only, and typically developing controls, particularly on subtests assessing visual memory. On the ROCF, children with DCD and at least one other disorder scored significantly lower than children with ADHD only or RD only. Children with DCD plus one other disorder were then subdivided into three groups: DCD + ADHD, DCD + RD, and DCD + ADHD + RD and compared to children with DCD only, ADHD only, and RD only. Results indicated that children with DCD + ADHD + RD had significant impairments on the TVPS compared to children with DCD only and children with ADHD only. On the ROCF, children with DCD + ADHD + RD scored significantly lower than all of the groups, except the DCD+RD group. These findings suggest that DCD on its own is not associated with visual perceptual problems; rather, it is the presence of co-occurring disorders that is a possible key to visual perceptual deficits in children with DCD. The number of co-occurring disorders present with DCD is associated with the severity of the visual perceptual dysfunction. Deficits in visual memory skills appear to be a specific area of difficulty for children with DCD and co-occurring RD and/or ADHD.     

Test of Alternative Hypotheses Explaining the Comorbidity Between Attention-Deficit/Hyperactivity Disorder and Conduct Disorder

There is significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD). The conclusions of studies that examined the causes of comorbidity between ADHD and CD conflict, with some researchers finding support for the three independent disorders model and others finding support for the correlated risk factors model. We tested these models and eleven alternative hypotheses using the same analytical approach. The participants were 110 monozygotic twin pairs and 181 dizygotic twin pairs recruited from the Colorado Learning Disabilities Research Center Twin Study. The three independent disorders model did not fit the data, whereas the correlated risk factors model fit the data well. Several other comorbidity models fit the data as well as or better than the correlated risk factors model. The results suggest that correlated risk factors are a better explanation for the comorbidity between ADHD and CD than a third, independent ADHD+CD subtype.     

Associations between Maternal Attention-Deficit/Hyperactivity Disorder Symptoms and Parenting

Mothers of children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for an ADHD diagnosis themselves, which is likely associated with impairments in parenting. The present study utilized a multi-method assessment of maternal ADHD and parenting to examine the extent to which maternal ADHD symptoms are associated with maladaptive parenting. Participants included 70 6–10 year old children with DSM-IV ADHD and their biological mothers. Results suggested that mothers with higher levels of ADHD symptoms reported lower levels of involvement and positive parenting and higher levels of inconsistent discipline. During observed parent–child interactions, maternal ADHD symptoms were negatively associated with positive parenting, and positively associated with negative parenting and repeated commands before giving the child an opportunity to comply. Given prior research suggesting that maladaptive parenting behaviors are risk factors for the later development of conduct problems among children with ADHD, these findings have important clinical implications for family-based assessment and treatment of ADHD.     

Is ADHD a disinhibitory disorder?

Attention deficit hyperactivity disorder (ADHD) is widely theorized to stem from dysfunctional inhibitory processes. However, the definition of inhibition is imprecisely distinguished across theories. To clarify the evidence for this conception, the author relies on a heuristic distinction between inhibition that is under executive control and inhibition that is under motivational control (anxiety or fear). It is argued that ADHD is unlikely to be due to a motivational inhibitory control deficit, although suggestions are made for additional studies that could overturn that conclusion. Evidence for a deficit in an executive motor inhibition process for the ADHD combined type is more compelling but is not equally strong for all forms of executive inhibitory control. Remaining issues include specificity to ADHD, whether inhibitory problems are primary or secondary in causing ADHD, role of comorbid anxiety and conduct disorder, and functional deficits in the inattentive ADHD subtype.     

ADHD,strain, and criminal behavior: a test of general strain theory

This study explores the relationship between attention deficit/hyperactivity disorder (ADHD), strain, and criminal behavior. This is an attempt to introduce ADHD, a psychological disorder, into the framework of general strain theory. Using a purposive sample of college students, we tested the hypothesis that individuals with self-reported symptoms of ADHD were more likely to participate in criminal behaviors when experiencing strain. We found that ADHD symptoms conditioned the effect of strain on crime. The results suggest that individuals at risk for ADHD may be less able to legitimately cope with strain compared to the rest of the population.     

Errors on a computer task and subclinical symptoms of attention‐deficit/hyperactivity disorder (ADHD)

Previous reports have found increased error rate for children with attention‐deficit/hyperactivity disorder (ADHD ) on response time (RT ) computer tasks. Here we attempt the conceptual replication and extension of two studies that examined error rate in a general population of children (N = 203). Study 1 followed Johnstone and Galletta but considered associations between scores on a dimensional measure of ADHD symptoms (rather than comparing those with or without an ADHD diagnosis) and the frequency of commission and omission errors. Study 2 followed Shiels, Tamm & Epstein and examined post‐error adjustment in the same group of children as for Study 1. Study 1 did not replicate previous findings of no increase in errors of commission in those with higher ADHD symptoms (Johnstone & Galletta). Instead, we found that younger children with lower ADHD symptoms were more likely to make commission errors, while omission errors did not vary with age. Study 2 replicated the previous finding of less RT slowing in children with more ADHD symptoms, extending this finding to a general population of children. Namely, as ADHD symptoms increase, RT slowing is less likely, putting children with higher ADHD symptoms at risk of additional errors. Overall, we extend previous ADHD research to typically developing children with ADHD symptoms.     

Etiology of Inattention and Hyperactivity/Impulsivity in a Community Sample of Twins with Learning Difficulties

A community sample of 373 8 to 18 year-old twin pairs in which at least one twin in each pair exhibited a history of learning difficulties was utilized to examine the etiology of inattention and hyperactivity/impulsivity (hyp/imp). Symptoms of attention-deficit/hyperactivity disorder (ADHD) were assessed by the DSM-III Diagnostic Interview for Children and Adolescents. Inattention and hyp/imp composite scores were created based on results of a factor analysis. Results indicated that extreme ADHD scores were almost entirely attributable to genetic influences across several increasingly extreme diagnostic cutoff scores. Extreme inattention scores were also highly heritable whether or not the proband exhibited extreme hyp/imp. In contrast, the heritability of extreme hyp/imp increased as a linear function of the number of inattention symptoms exhibited by the proband. This finding suggests that extreme hyp/imp may be attributable to different etiological influences in individuals with and without extreme inattention. If this result can be replicated in other samples, it would provide evidence that the hyp/imp symptoms exhibited by individuals with Combined Type ADHD and Predominantly Hyp/Imp Type ADHD may be attributable to different etiological influences.     

Aggression Among Children with ADHD,Anxiety, or Co-occurring Symptoms: Competing Exacerbation and Attenuation Hypotheses

Competing hypotheses for explaining the role of anxiety in the relation between attention-deficit/hyperactivity disorder (ADHD) symptoms and childhood aggression were evaluated. Two studies tested whether anxiety exacerbated, attenuated, or had no effect on the relation between ADHD and aggression subtypes among psychiatrically hospitalized children. In Study 1 (N = 99), children who scored above clinical cut-off levels for anxiety only, ADHD only, and co-occurring ADHD and anxiety were compared on aggression subtypes (i.e., reactive, proactive, overt, and relational aggression). In Study 2, the moderating role of anxiety on the relation between ADHD and aggression subtypes was examined with a larger sample (N = 265) and with continuous variables. No support was found for either the attenuation or exacerbation hypothesis, and results remained consistent when separately examining hyperactivity/impulsivity and inattention symptoms of ADHD. Although ADHD symptoms were significantly associated with all aggression subtypes, this association did not remain when including symptoms of oppositional defiant disorder.