Internal Validity of the Disruptive Behavior Disorder Symptoms: Implications from Parent Ratings for a Dimensional Approach to Symptom Validity

A dimensional approach was used to evaluate the internal validity of the DSM-III-R ADHD-inattention, ADHD-hyperactivity/impulsivity, oppositional defiant disorder (ODD), and conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension than the other three). Parents rated 4,019 children between the ages of 2 and 19 on these symptoms. The results showed that 5 of the 6 inattention symptoms, 3 of the 4 hyperactivity symptoms, 1 of the 4 impulsivity symptoms, 6 of the 9 oppositional defiant disorder symptoms, and 8 of the 11 CD symptoms had significant internal validity. Confirmatory factor analysis (CFA) found support for inattention, hyperactivity/impulsivity, oppositional defiant, and conduct disorder dimensions. Multiple-group CFA also found support for factor pattern and loading invariance across gender. The implications of these results as well as the merits of the dimensional approach to symptom validity are discussed in the context of the DSM-IV changes in ADHD, ODD, and CD.     

A confirmatory factor analysis on the DSM-IV ADHD and ODD symptoms: what is the best model for the organization of these symptoms?

Confirmatory factor analysis (CFA) was used to evaluate five different models for the organization of the DSM-IV ADHD and oppositional defiant disorder (ODD) symptoms (Model 1: a single factor model; Model 2: an ADHD and ODD two factor model; Model 3a: an inattention (INA), hyperactivity/impulsivity (HYP/IMP), and ODD three factor model; Model 3b: an INA, HYP/IMP, and ODD three factor model where the three IMP symptoms cross-load on the ODD factor; Model 4: an INA, HYP, IMP, and ODD four factor model). To evaluate these models, maternal ratings of ADHD and ODD symptoms were obtained at outpatient pediatric clinics on 742 children not in treatment and 91 children in treatment for ADHD. Model 3a resulted in a good fit as well as a significantly better fit than Model 2. Model 3a was also equivalent across treatment status, gender, and age groupings for the most part. Though Models 3b and 4 provided a statistically better fit than Model 3a, the improvement in fit was small and other model selection criteria argued against these more complex models.     

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.     

Waiting impulsivity: a distinctive feature of ADHD neuropsychology?

Impulsivity is a core feature of attention-deficit hyperactivity disorder (ADHD). It has been conceptualized in a number of different ways. In the current article, we examine how the new concept of “waiting impulsivity”, which refers to premature responding before a scheduled target appears, adds to our understanding of impulsivity in ADHD. Sixty children (8–12 years old; 30 ADHD; 30 typically developing controls) completed the 4-choice serial reaction time task, a measure of waiting impulsivity, alongside tasks measuring inhibitory control and temporal discounting and questionnaires measuring behavioral disorder symptoms, delay aversion, and various aspects of impulsivity. A multiple logistic regression model was used to explore the contribution of the primary task outcomes to predict group membership. Children with ADHD displayed more waiting impulsivity and less inhibitory control; they did not differ in temporal discounting. There was no correlation between waiting impulsivity and inhibitory control. Waiting impulsivity was correlated with parent-reported ratings of hyperactivity/impulsivity, inattention, oppositional defiant disorder (ODD), and conduct disorder (CD) and with self-reported delay aversion ratings. Only waiting impulsivity was a significant predictor of ADHD status. In conclusion, waiting impulsivity is distinct from inhibitory control deficits and predicts ADHD status independently of it. Future research needs to examine the relationship with delay aversion and ODD/CD more thoroughly.     

Factor Structure and Criterion Validity of Secondary School Teacher Ratings of ADHD and ODD

Attention-Deficit Hyperactivity Disorder (ADHD) is currently viewed as a heterogeneous disorder with two factors: inattention and impulsivity–hyperactivity. This conceptualization of ADHD is based primarily on research with children or samples that mix children and adolescents. To examine if the 2-factor ADHD model is appropriate for adolescents and if the ADHD factors are distinct from Oppositional Defiant Disorder (ODD) in adolescents, teacher rating data were collected for 2 samples of adolescents. The results of a confirmatory factor analysis supported the convergent and divergent validity of a model with separate but correlated factors for inattention, impulsivity–hyperactivity, and defiant behavior. Further evidence of construct validity was found when factor scores were examined relative to the criterion variables of academic performance and rule-breaking behavior. The results support the utility of teacher ratings of ADHD and ODD in the assessment of adolescents, and the applicability of the DSM-IV conceptualization of these disorders to adolescents.     

Evidence for a general factor model of ADHD in adults

Objective: To examine factor structures of Diagnostic and Statistical Manual of Mental Disorders (4th ed.) symptoms of ADHD in adults. Method: Two sets of models were tested: (a) models with inattention and hyperactivity/impulsivity as separate but correlated latent constructs and (b) hierarchical general factor models with a general factor for all symptoms and separate specific factors for inattention and hyperactivity/impulsivity. Participants were 751 adults with ADHD. Two models with correlated factors and two general factor models of ADHD symptoms were tested. Results: The general factor model provided a better fit of the data than the correlated models. The general factor model with one general and three (inattention, motoric, and verbal hyperactivity/impulsivity) specific factors best accounted for the adults' symptoms. Conclusion: These results suggest a unitary component to ADHD symptoms as well as dimensional specific factors. The replication of a general factor in adults suggests continuity of symptom presentation from childhood into adulthood. Clinical implications are discussed.     

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.     

A Preliminary Study of ADHD Symptoms and Correlates: Do Abused Children Differ from Nonabused Children?

In this pilot study, differences in inattention, impulsivity, and hyperactivity as well as demographic factors were investigated in a community sample of 8- through 11-year-olds, approximately half of whom had experienced child abuse or neglect. Parents completed the Attention Deficit Hyperactivity Disorder Test, the SNAP-IV, the Brief Betrayal Trauma Survey – Parent version, and additional questions. Abused children had more severe impulsivity and inattention, but not hyperactivity, symptoms. Abused boys and girls had a similar age of onset of symptoms, whereas nonabused girls had a much later age of onset than nonabused boys. ADHD is a significant problem among maltreated children. These data support large scale studies investigating possible differences in etiology, presentation, and treatment.     

The influence of ADHD-hyperactivity/impulsivity symptoms on the development of oppositional defiant disorder symptoms in a 2-year longitudinal study

The structural relations among ADHD–inattention (IN), ADHD–hyperactivity/impulsivity (H/I), and oppositional defiant disorder (ODD) factors were examined in a 2-year longitudinal study with 752 children. Structural equation procedures showed that higher scores on the H/I factor in Year 1 were associated with higher scores on ODD factor in Years 2 and 3. Higher scores on the H/I factor in Year 2 were also associated with higher scores on ODD factor in Year 3. The ODD factor did not predict the H/I and IN factors in subsequent years. The IN factor did not predict the ODD and H/I factors in subsequent years and the H/I factor did not predict the IN factor. The ability of the H/I factor to predict the subsequent ODD factor occurred even after taking into account the ability of the ODD, H/I, and IN factors to predict themselves across time. These results suggest that the H/I aspect of ADHD influences the development of ODD behavior.     

Paired-Associate Learning in Attention-Deficit/Hyperactivity Disorder as a Function of Hyperactivity-Impulsivity and Oppositional Defiant Disorder

A paired-associate learning (PAL) test was administered to 22 community volunteers without disruptive disorders and 197 children (7.5–13.5 years-old) presenting with the inattentive and combined subtypes of attention-deficit/hyperactivity disorder (ADHD) either in combination with or without oppositional defiant disorder (ODD). Participants were screened for learning disorders. In comparison to non-ADHD participants, children with ADHD achieved worse PAL and made errors rated as more acoustically and less semantically similar to the correct paired associates. These deficits were not related to hyperactivity–impulsivity or comorbid ODD. These results suggest that ADHD children are less competent at PAL and use less efficient learning strategies than their non-ADHD peers.     

Unintentional Injury Risk in Children with Externalizing Behavior Disorders at Summer Camp

Children with externalizing behavior disorders such as attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) have greatly increased risk of unintentional injury, but it is unclear what mechanisms are responsible for that increased risk. This study followed 22 children participating in a summer camp for children with ADHD. Injury incidents were recorded daily and a set of primary symptoms of behavioral disorders were recorded at 15-min intervals over the course of the 6-week summer camp experience (roughly 300 h of observing each child). We predicted symptoms of ODD and CD would be more strongly related to injury incidence than symptoms of ADHD. Results from univariate Poisson regression models confirmed our prediction. Symptoms of ODD and CD—violations and intentional aggression in particular—were related to injury incidence but symptoms of ADHD were not. This finding is consistent with a growing body of evidence that oppositional, noncompliant, and aggressive behavior patterns might be primarily responsible for increased risk for injury among children with externalizing behavior disorders. Thanks to Sylvie Mrug, Peter Winslett, and the other staff members of the STP camp for their cooperation.     

Experiences of physical and relational victimization in children with ADHD: The role of social problems and aggression

The social risk factors for physical and relational peer victimization were examined within a mixed‐gender sample of children with and without attention‐deficit/hyperactivity disorder (ADHD). Participants were 124 children (ages 8–12 years; 48% boys), with 47% exhibiting sub‐clinical or clinical elevations in ADHD symptoms. ADHD and oppositional defiant disorder (ODD) symptom counts were assessed based on parent‐ and teacher‐reports; parents rated children's social problems and teachers rated children's use of physical and relational aggression and experiences of physical and relational victimization. A multiple mediator model was used to test whether there were indirect effects of ADHD or ODD symptoms on physical and relational victimization through social problems, physical aggression, or relational aggression. At the bivariate level, ADHD and ODD symptoms were both significantly associated with higher rates of physical and relational victimization. In the mediational model, there were significant indirect effects of ADHD symptoms on relational victimization via social problems, of ODD on relational victimization via relational aggression, and of ODD symptoms on physical victimization via physical aggression. Results suggest that there are distinct risk factors implicated in the physical and relational victimization of youth with ADHD and that the co‐occurrence of ODD symptoms is important to assess. Clinical implications for addressing victimization in children with ADHD are discussed.

     

成人注意缺陷多动障碍在内外源冲突时的表现:眼动的证据

在注意定向与维持上,注意缺陷多动障碍(ADHD)个体更容易受到外部刺激的干扰而导致目标任务加工进程受阻,表现出了注意定向反应的缺陷,但导致任务失败的原因是由于对突然出现的外部无关刺激的过度兴奋还是对内源性目标刺激的持续维持能力减弱,尚不清楚。研究采用反向眼跳范式、记忆导向眼跳范式和视觉导向眼跳范式,来探索成人ADHD内外源注意定向反应的情况,以及当二者发生冲突时,成人ADHD失败的可能机制。结果发现,在反向眼跳任务上,成人注意缺陷多动障碍组错误率更高,并且差异性显著。但在记忆导向眼跳任务中,成人注意缺陷多动障碍组与正常组的差异不显著。在视觉导向眼跳任务中,成人注意缺陷多动障碍组的正确眼跳潜伏期比正常组要短,且二者之间的差异显著。这说明,在内外源刺激反应的冲突导致的情境中,成人注意缺陷多动障碍的反应明显落后于正常个体,这种缺陷并非由于其维持内源性注意产生定向反应落后所导致的,而是与其外源注意定向反应过强有关。     

The Factor Structure of ADHD – Different Models,Analyses and Informants in a Bifactor Framework

The methodological approach of exploratory structural equation modelling (ESEM) has only been applied once to the construct of Attention-deficit/hyperactivity disorder (ADHD). We decided to compare bifactor models based on confirmatory factor analyses (Bi-CFA) and exploratory equation modeling (Bi-ESEM) only, as there is a growing support of a bifactor structure of ADHD. To examine the factorial validity of the construct we compared three possible bifactor models. One model with two specific factors (inattention and hyperactivity/impulsivity), another model with three specific factors (inattention, hyperactivity and impulsivity) and an alternative, incomplete model with one general ADHD and two specific factors (inattention and impulsivity). We used parent- (N = 1386; Age: M = 11.70, SD = 3.18; Sex: 74.5 % male) and teacher-ratings (N = 110; Age: M = 11.27, SD = 3.04; Sex: 77.5 % male) from clinically referred children between the age of 6 and 18. The results indicate that both methods lead to equally good model fit and for both informants the reliable variance of the specific factor hyperactivity is almost completely explained by the general factor. However, in the teacher condition cross-loadings seem to be of particular importance. Across both methods and informants covariation among ADHD symptom items can be in most part attributed to a general ADHD factor as well as to three (inattention, hyperactivity and impulsivity) or two (inattention and impulsivity) weakly defined specific factors. Further research regarding associations between the specific factors of ADHD and other disorders (e.g. conduct disorder) should be conducted.     

Understanding the Covariation Among Childhood Externalizing Symptoms: Genetic and Environmental Influences on Conduct Disorder,Attention Deficit Hyperactivity Disorder,and Oppositional Defiant Disorder Symptoms

Conduct disorder (CD), attention deficit hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) are common childhood externalizing disorders that frequently co-occur. However, the causes of their comorbidity are not well understood. To address that question, we analyzed data from > 600 Finnish twin pairs, who completed standardized interviews at age 14. Behavior genetic methods were used to examine how genetic/environmental factors contribute to each disorders symptoms and to their covariation. We found significant genetic effects on each disorder with only modest evidence of shared environmental influences. Our data suggest the comorbidity among CD, ADHD, and ODD is primarily explained by shared genetic influences; however, each disorder was also under unique genetic influence, supporting the distinction of each disorder.     

The relationship of compliance with inattention and hyperactivity/impulsivity

The aim of the study was to investigate the relationship between Attention Deficit Hyperactivity Disorder (ADHD) inattention and hyperactivity/impulsivity symptoms in predicting compliance. It was hypothesised that inattention symptoms are a better predictor of compliance than hyperactivity/impulsivity. There were two different groups of participants: 367 college students (both males and females) and 89 male prisoners. All participants had completed the Gudjonsson Compliance Scale (GCS) and the DSM-IV-TR (Screening) Checklist for adult ADHD symptoms. Significant correlations emerged between compliance and ADHD symptoms, but the correlations were higher for inattention than hyperactivity/impulsivity among both samples. This was confirmed by multiple regression analyses (hierarchical), which showed that the variance in compliance explained by ADHD inattention versus hyperactivity/impulsivity symptoms increased from 2% to 8% for college students and 8% to 24% for prisoners after entering inattention into the model (hyperactivity/impulsivity was entered first in the regression models). The findings suggest that inattention is a more powerful predictor of compliance than hyperactivity/impulsivity. This is a novel and an important finding.     

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.     

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.     

The Relation Between Sluggish Cognitive Tempo and DSM-IV ADHD

To test the relation between sluggish cognitive tempo (SCT) and DSM-IV ADHD symptoms, parent and teacher ratings of the 18 DSM-IV ADHD items and five potential SCT items were obtained in a community sample of 8-18 year-old twins that was overselected for ADHD and learning disabilities (n = 296). Confirmatory factor analyses revealed that a three-factor model provided the best fit to the data for both parent and teacher ratings. DSM-IV inattention and hyperactivity-impulsivity symptoms loaded on two factors consistent with the DSM-IV model, and five SCT symptoms loaded primarily on a third factor. The SCT and inattention factors were highly correlated, whereas SCT and hyperactivity-impulsivity were weakly related. Both raters indicated that children meeting symptom criteria for the combined and inattentive subtypes exhibited significantly more SCT symptoms than those meeting symptom criteria for hyperactive-impulsive type and the comparison group without ADHD. Children meeting symptom criteria for the inattentive type exhibited significantly more SCT symptoms than those meeting criteria for the combined type, based on teacher ratings. These results suggest that SCT is an internally consistent construct that is significantly associated with DSM-IV inattention.