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.     

Antisocial behavior reduces the association between subdimensions of ADHD symptoms and alcohol use in a large population‐based sample of adolescents

The aim of this study was to investigate possible effects of antisocial behavior on reducing the association between subdimensions of ADHD symptoms (inattention, hyperactivity and impulsivity) and alcohol use. Boys and girls were analyzed separately using a population‐based Swedish adolescent sample. A randomly selected cross‐sectional survey was performed in secondary and upper secondary schools in Västmanland County during 2010. Participants were a population of 2,439 15–16 year‐olds and 1,425 17–18 year‐olds (1,947 girls and 1,917 boys). Psychosocial adversity, antisocial behaviors, symptoms of ADHD and alcohol use were assessed by questionnaires. Except for girls' inattention, subdimensions of ADHD symptoms were not associated with alcohol use when variance due to antisocial behavior was accounted for. Among boys, instead of an indirect effect of antisocial behavior on the association between impulsivity and alcohol use, a moderating effect was found. Among girls, the inattention component of ADHD was independently associated with alcohol use even when adjusted for antisocial behavior. The reduced associations between symptoms of hyperactivity, impulsivity, and alcohol use for boys and girls after adjusting for antisocial behavior suggest a considerable overlap between hyperactivity, impulsivity, and antisocial behavior. The direct pathway between inattention and alcohol use among girls suggests that girls with inattention symptoms are at risk of alcohol use regardless of antisocial behavior. Special attention should be given to these girls. Accounting for antisocial behavior reduced the relation between subdimensions of ADHD symptoms and alcohol use, and antisocial behaviors should therefore be screened for when symptoms of ADHD are present.     

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.     

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.     

Assessing inattention and impulsivity in children during the Go/NoGo task

Behavioural performance in the Go/NoGo task was compared with caregiver and teacher reports of inattention and hyperactivity‐impulsivity in 1,151 children (N=557 boys; N=594 girls) age 9–10 years old. Errors of commission (NoGo errors) were significantly correlated with symptom counts of hyperactivity‐impulsivity, while errors of omission (Go errors) were significantly correlated with symptom counts for inattention in both caregiver and teacher reports. Cross‐correlations were also evident, however, such that errors of commission were related to inattention symptoms, and errors of omission were related to hyperactivity‐impulsivity. Moreover, hyperactivity‐impulsivity and inattention symptoms were highly intercorrelated in both caregiver (r=.52) and teacher reports (r=.70), while errors of commission and omission were virtually uncorrelated in the Go/NoGo task (r=.06). The results highlight the difficulty in disentangling hyperactivity‐impulsivity and inattention in questionnaires, and suggest that these constructs may be more clearly distinguished in laboratory measures such as the Go/NoGo task.     

The Unity and Diversity of Inattention and Hyperactivity/Impulsivity in ADHD: Evidence for a General Factor with Separable Dimensions

To examine the unity and diversity of inattention and hyperactivity/impulsivity symptom domains of Attention-Deficit/Hyperactivity Disorder (ADHD) in a clinical sample of adolescents with ADHD. Parents and adolescents were administered a semi-structured diagnostic interview, the Schedule for Affective Disorders and Schizophrenia for School-Age Children — Present and Lifetime Version (K-SADS-PL), to assess adolescent ADHD. Data from 201 parent interviews and 189 adolescent interviews were examined. Four potential factor structures for the 18 ADHD symptoms were tested using confirmatory factor analysis: two models with correlated factors and two bifactor models. A bifactor model with two specific factors best accounted for adolescent symptoms, according to both parent and adolescents’ reports. Replication of these findings from behavioral rating scales completed for this sample by parents and teachers indicates that the findings are not method– or informant-specific. The results suggest that there is an important unitary component to ADHD symptoms and separable dimensional traits of Inattention and Hyperactivity/Impulsivity.     

Dimensions and Correlates of Attention Deficit/Hyperactivity Disorder and Sluggish Cognitive Tempo

The present study examined Sluggish Cognitive Tempo (SCT) in relation to ADHD symptoms, clinical diagnosis, and multiple aspects of adjustment in a clinical sample. Parent and teacher reports were gathered for 322 children and adolescents evaluated for behavioral, emotional, and/or learning problems at a university clinic. Confirmatory factor analyses (CFA) supported the presence of three separate, but correlated factors (SCT, inattention, and hyperactivity/impulsivity) in both parent and teacher ratings. As expected, SCT symptoms were greatest in youth with ADHD Inattentive type, but were also found in non-ADHD clinical groups. SCT symptoms were related to inattention, internalizing, and social problems across both parent and teacher informants; for parent reports, SCT was also related to more externalizing problems. Findings support the statistical validity of the SCT construct, but its clinical utility is still unclear.     

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.     

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.     

Reliable Ratings or Reading Tea Leaves: Can Parent,Teacher, and Clinician Behavioral Ratings of Preschoolers Predict ADHD at Age Six?

To assess the relative ability of parent, teacher, and clinician behavioral ratings of preschoolers to predict ADHD severity and diagnosis at 6 years of age. Hyperactive/inattentive preschoolers [N?=?104, 75 % boys, Mean (SD) age?=?4.37 (0.47) years] were followed over 2 years (mean?=?26.44 months, SD?=?5.66). At baseline (BL), parents and teachers completed the ADHD-RS-IV and clinicians completed the Behavioral Rating Inventory for Children following a psychological testing session. At age 6, [Mean (SD) age?=?6.62 (0.35) years], parents were interviewed with the K-SADS-PL; teachers completed the ADHD-RS-IV; and laboratory measures of hyperactivity, impulsivity, and inattention were obtained from children. Hierarchical logistic and linear regression analyses examined which combination of BL ratings best predicted 6-year-old ADHD diagnosis and severity, respectively. At age 6, 56 (53.8 %) children met DSM-IV criteria for a diagnosis of ADHD. BL ratings from parent/teacher/clinician, parent/teacher and parent/clinician combinations significantly predicted children who had an ADHD diagnosis at age 6. Parent and clinician, but not teacher, behavior ratings were significant independent predictors of ADHD diagnosis and severity at 6-years-old. However, only clinician reports of preschoolers’ behaviors predicted laboratory measures of over-activity and inattention at follow-up. Cross-situationality is important for a diagnosis of ADHD during the preschool years. Among parents, teachers and clinicians, positive endorsements from all three informants, parent/teacher or parent/clinician appear to have prognostic value. Clinicians’ ratings of preschoolers’ inattention, impulsivity and hyperactivity are valid sources of information for predicting ADHD diagnosis and severity over time.     

Do Parent and Teacher Report of ADHD Symptoms in Children Differ by SES and Racial Status?

Parent and teacher reports of symptoms of Attention Deficit Hyperactivity Disorder (ADHD) in children often differ from each other. These informant report differences may occur in systematic ways that vary by child socioeconomic status (SES) and race, but little is known about how SES and race together relate to parent and teacher report of ADHD symptoms in school-aged children. We examined the relationship between child SES, child race and parent and teacher reports of ADHD symptoms in two samples of school-aged Caucasian and African American children being evaluated for ADHD (N = 1056; N = 317). Multivariate regression was used to predict parent and teacher reports of ADHD symptoms from child SES, race, age, gender and interaction terms. The Wald test of parameter constraints was used to test the contrast between the predictors of interest and parent and teacher report of symptoms. In the second sample, we also examined observer report measures of ADHD symptoms during one-to-one testing and in the classroom. In both samples, lower SES was associated with higher levels of inattention symptoms, as reported by teachers, but not by parents. Lower SES was also associated with higher levels of hyperactivity/impulsivity symptoms, as reported by both teachers and parents. African American race was associated with higher levels of inattention and hyperactivity/impulsivity symptoms reported by teachers than reported by parents. Observer report measures showed a different pattern of associations with SES and race. Investigating how children’s SES and race influence cross-informant agreement on ratings of children’s behavior might lead to the development of better assessment practices and more accurate diagnoses for diverse child populations.     

Sex differences in school-aged children with pervasive attention deficit hyperactivity disorder

This study investigated 54 children (37 boys and 17 girls) with cross-situational attention deficit hyperactivity disorder (ADHD) to determine whether there are sex differences in the expression of either the primary or secondary symptomatology of ADHD. Results indicated that the male and female ADHD groups were strikingly similar on all measures of primary (impulsivity, inattention, and overactivity) and secondary (learning problems, externalizing symptoms, internalizing symptoms, peer relationship difficulties, and self-perceptions) symptomatology included in this study. The lack of significant sex differences conflicts with prior reports in the literature, and these conflicting results are discussed in terms of differences in inclusion criteria. Implications for understanding the long-term outcome of ADHD in girls are also discussed.     

Equivalence of mother and father ratings of ADHD in children

Obtaining data from multiple informants provides a more comprehensive diagnostic picture in the assessment of attention deficit hyperactivity disorder (ADHD). Differences in symptom ratings have been observed between parent- and teacher-report scales, though less information is available regarding differences between mothers and fathers. To address this gap, this study examines the rater agreement between mothers and fathers on the Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition (DSM-IV) ADHD Symptom Rating Scale (DSM-ADHD-SRS). The participants consisted of 337 children diagnosed with ADHD who underwent comprehensive neuropsychological assessment. Confirmatory factor analysis indicates that a three-factor model comprising inattention, hyperactivity, and impulsivity symptoms provides the best fit for both mothers’ and fathers’ ratings. Mothers provided higher mean ratings for the inattention scale. These results suggest that the factor structure for the DSM-ADHD-SRS is the same, regardless of parent gender. However, symptoms of inattention may vary depending upon which parent completes the ratings. This discrepancy could lead to differences in diagnostic impressions in clinical evaluations.     

Measurement and structural invariance of parent ratings of ADHD and ODD symptoms across gender for American and Malaysian children

The purpose of this study was to examine the measurement (configural, metric, scalar, and residual) and structural (factor variance, factor covariance, and factor means) invariance of parent ratings of the attention-deficit/hyperactivity disorder - inattention (ADHD-IN), ADHD - hyperactivity/impulsivity (ADHD-HI), and oppositional defiant disorder (ODD) symptoms as described in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) across boys and girls. In an American pediatric sample (N = 1,015) and a Malaysian elementary school-age sample (N = 928), there was strong support for configural, metric, scalar, residual, factor variance, and covariance invariance across gender within each sample. Both American and Malaysian boys had significantly higher scores on the ADHD-IN and ADHD-HI factor means than did girls, whereas only in the American sample did boys score significantly higher on the ODD factor than did girls. The implications of the results for the study of gender, ethnic, and cultural differences associated with ADHD and ODD are discussed.     

Teachers' screening for attention deficit/hyperactivity disorder: comparing multinational samples on teacher ratings of ADHD

This study evaluates a measurement model for Attention Deficit/Hyperactivity Disorder (ADHD). The DSM-IV divides 18 symptoms into two groups, inattentive and hyperactive/impulsive. Elementary school teachers rated 21,161 children in 4 locations: Spain, Germany, urban US, and suburban US. Confirmatory factor analysis suggested that the 2-factor model (inattention, hyperactivity/impulsivity) shows the best fit. A third factor, impulsivity, was too slight to stand-alone. Children with academic performance problems were distinguished by inattention, but children with behavior problems typically had elevations in inattention, hyperactivity, and impulsivity. Between-site differences were statistically significant, but so small that we conclude that same measurement model fits all 4 samples in 2 continents.     

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.     

Parent–Adolescent Agreement on Disruptive Behavior Symptoms: A Multitrait-Multimethod Model

This study examined parent–adolescent agreement on reports of inattention, hyperactivity/impulsivity, and conduct disorder in 203 adolescents (94 girls, 109 boys) ranging in age from 13 to 18 years (M = 15.21, SD = 1.37). Results of confirmatory factor analyses provided additional evidence of construct validity for these traits in adolescents. Internal consistency was examined for parent reports and adolescent self-reports. In addition, correlational analyses were used in a multitrait-multimethod format (MTMM; D. T. Campbell & D. W. Fiske, 1959) to examine convergent and discriminant validity. Results showed that parents provided more consistent and valid reports of inattention and hyperactivity/impulsivity, whereas adolescents provided more consistent and valid reports of conduct disorder. In addition, interviews produced higher levels of convergence than rating scales. These findings are discussed in terms of implications for assessment of disruptive behavior disorders.     

The structure of childhood disruptive behaviors

Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) frequently co-occur. Comorbidity of these 2 childhood disruptive behavior domains has not been satisfactorily explained at either a structural or etiological level. The current study evaluated a bifactor model, which allows for a "g" factor in addition to distinct component factors, in relation to other models to improve understanding of the structural relationship between ADHD and ODD. Participants were 548 children (321 boys, 227 girls) between the ages of 6 years and 18 years who participated in a comprehensive diagnostic assessment incorporating parent and teacher ratings of symptoms. Of these 548 children, 153 children were diagnosed with ADHD (without ODD), 114 children were diagnosed with ADHD + ODD, 26 children were diagnosed with ODD (without ADHD), and 239 children were classified as non-ADHD/ODD comparison children (including subthreshold cases). ADHD symptoms were assessed via parent report on a diagnostic interview and via parent and teacher report on the ADHD Rating Scale. ODD symptoms were assessed via teacher report. A bifactor model of disruptive behavior, comprising a "g" factor and the specific factors of ADHD and ODD, exhibited best fit, compared to 1-factor, 2-factor, 3-factor, and 2nd-order factor models of disruptive behaviors. It is concluded that a bifactor model of childhood disruptive behaviors is superior to existing models and may help explain common patterns of comorbidity between ADHD and ODD.     

Agreement Between Parent and Teacher Ratings of Disruptive Behavior Disorders in Children with Clinically Diagnosed ADHD

This study investigated the agreement between parent and teacher ratings of DSM-IV symptoms of Attention Deficit Hyperactivity Disorder (ADHD) and related disorders: Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD). A sample of 55 children in the age range of 6–12 years with clinically diagnosed ADHD participated in the study. Parents and teachers were asked to complete the Disruptive Behavior Disorder Rating Scale (DBDRS; W. E., Pelham, E. M., Gnagy, K. E., Greenslade, & R. Milich, 1992). No association was found between parent and teacher ratings of inattention and hyperactivity/impulsivity. However, moderate to high levels of agreement were obtained for ratings of symptoms that characterized ODD and CD. The observed low levels of agreement between parent and teacher ratings of ADHD symptoms may be attributed to different perceptions of the problem behavior by parents and teachers, medication effects, or the situation specificity of children's behavior. It is recommended that the diagnostic criterion of symptom pervasiveness for the diagnosis of ADHD be operationalized more clearly.     

Gender differences on the Five to Fifteen questionnaire in a non‐referred sample with inattention and hyperactivity‐impulsivity and a clinic‐referred sample with hyperkinetic disorder

Lambek, R., Trillingsgaard, A., Kadesjö, B., Damm, D. & Thomsen, P. H. (2010). Gender differences on the Five to Fifteen questionnaire in a non‐referred sample with inattention and hyperactivity‐impulsivity and a clinic‐referred sample with hyperkinetic disorder. Scandinavian Journal of Psychology 51, 540–447. The aim of the present study was to examine gender differences in children with inattention, hyperactivity, and impulsivity on the Five to Fifteen (FTF) parent questionnaire. First, non‐referred girls (n = 43) and boys (n = 51) with problems of attention and hyperactivity‐impulsivity and then clinic‐referred girls (n = 35) and boys (n = 66) with hyperkinetic disorder (HKD) were compared on the FTF. Results suggested that non‐referred boys were more hyperactive‐impulsive than non‐referred girls, whereas clinic‐referred boys and girl with HKD were more similar than dissimilar on the FTF questionnaire. Secondly, it was examined whether the application of gender mixed norms versus gender specific norms would result in varying proportions of clinic‐referred children with HKD being identified as impaired on the subdomains of the FTF questionnaire. Based on results it was concluded that the use of a gender mixed normative sample may lead to overestimation of impairment in boys with HKD, but the type of sample applied to define impairment on the FTF should depend on the purpose for applying the questionnaire.