Kathleen E. McKay

Parent–Teacher Concordance for DSM-IV Attention-Deficit/Hyperactivity Disorder in a Clinic-Referred Sample

OBJECTIVE To examine concordance between parent and teacher reports of DSM-IV attention-deficit/hyperactivity disorder (ADHD) and its symptoms. METHOD Parents and teachers of 74 clinically referred children were interviewed using the ADHD module of the Diagnostic Interview Schedule for Children. Parent-teacher agreement for the diagnosis of ADHD and its subtypes, as defined in DSM-IV, as well as parent-teacher concordance of in-school ADHD symptoms, was examined. RESULTS Agreement between parents and teachers was found to be relatively poor, with virtually no agreement for individual ADHD subtypes. Diagnoses based on either parent or teacher report frequently yielded a diagnosis of either inattentive or hyperactive-impulsive subtype of ADHD. However, when cross-informant data were used to form diagnoses, these subtypes became relatively rare, with most cases meeting criteria for ADHD combined type. In addition, parent reports of in-school behavior were more highly correlated with their own reports of their childs behavior at home than with teacher reports of their childs behavior in school. CONCLUSIONS These data suggest that the diagnosis of ADHD inattentive or hyperactive-impulsive subtype based on data from a single informant may be of questionable validity, and they point to the importance of using multiple informants when diagnosing this disorder in clinically referred samples.

Developmental analysis of three aspects of information processing: Sustained attention, selective attention, and response organization

The development of cognitive abilities associated with Lunas (1973) three functional units of the brain was investigated in a sample of 62 children, ages 7 to 11 years, and 16 adults, ages 21 to 48 years. Selective attention, associated primarily with Lurias sensory‐input unit, showed no demonstrable development within the age ranges studied. However, sustained attention, presumably mediated through Lurias arousal unit and its ascending fibers to the cortex, as well as response organization, associated with Lunas organization‐and‐ planning unit, did reflect differential development Capacity for sustained attention showed no appreciable development between 7 and 11 years of age, but there was significant growth in this ability between age 11 and adulthood. Response organization, on the other hand, was found to develop most rapidly between 7 and 11 years of age. These findings are partially consistent with Lurias model of neurodevelopment as well as with research investigating the functional and physio...

Discriminant Validity of Attention-Deficit Hyperactivity Disorder

OBJECTIVE The primary purpose of this study was to assess the discriminant validity of attention-deficit hyperactivity disorder (ADHD) relative to well-defined groups of children with other psychiatric disorders. METHOD Clinic-referred patients diagnosed as having ADHD without any other comorbid diagnosis (N = 13), were compared with patients with only anxiety disorders (N = 20), disruptive disorders other than ADHD (N = 15), and nonreferred controls (N = 18) on measures of cognitive and academic functioning, as well as on objective measures of attention, impulse control, and activity level. RESULTS All three patient groups were found to have cognitive and academic achievement difficulties relative to controls. However, the ADHD group was found to be inattentive and impulsive relative to the other patient groups and the nonreferred controls. Objective measurement of activity level distinguished the ADHD group from controls but not from the other two patient groups. CONCLUSIONS These data support the diagnostic validity of a small subgroup of ADHD children (i.e., those without comorbid diagnoses) and demonstrates, that as a group, these children can be distinguished from patients with anxiety as well as other disruptive disorders on objective test measures.

Serotonin, Aggression, and Parental Psychopathology in Children With Attention-Deficit Hyperactivity Disorder

OBJECTIVE To explore the relationship between central serotonergic (5-HT) function and history of parental aggression in aggressive and nonaggressive boys with attention-deficit hyperactivity disorder (ADHD). METHOD History of psychiatric symptoms was assessed in the biological parents of 41 boys with ADHD. The relationship between 5-HT function in aggressive and nonaggressive probands, as assessed via the prolactin response to fenfluramine (FEN) challenge, and parental history of aggression was examined. RESULTS Aggressive boys with a parental history of aggressive behavior had a significantly lower prolactin response to FEN challenge than aggressive boys without a parental history of aggression. Nonaggressive boys had a prolactin response midway between those of the two aggressive subgroups, and their prolactin response did not vary as a function of parental aggression. Children subdivided on the basis of parental history of other psychiatric symptoms did not differ in their response to the FEN challenge. CONCLUSIONS These data indicate an association between parent aggressive behavior and lower 5-HT function in aggressive boys with ADHD but do not indicate the extent to which this association is environmentally and/or genetically transmitted. There may be different neurochemical mechanisms in familial and nonfamilial aggressive children, which have clinical implications for pharmacological interventions.

Noradrenergic mechanisms in ADHD children with and without reading disabilities: a replication and extension.

OBJECTIVE To examine noradrenergic (NA) function in children with attention-deficit hyperactivity disorder (ADHD) by replicating and expanding upon a previous finding that ADHD children with and without reading disabilities (RD) differ in plasma levels of the NA metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG). METHOD Plasma levels of MHPG were compared in ADHD children who were subdivided on the basis of the presence or absence of RD. Subsequently, this replication sample was combined with a previously studied sample to further explore the relationship between plasma MHPG levels and measures of cognitive function in children with ADHD. RESULTS Plasma levels of MHPG were significantly lower in ADHD children without RD, compared with those with RD, replicating a published finding. Analyses in the combined sample indicated that, among children with ADHD, plasma MHPG levels were inversely associated with measures of academic achievement and verbal processing, but not parent or teacher ratings of behavior or continuous performance test measures of attention and impulsivity. CONCLUSIONS These data indicate that children with ADHD are not homogeneous with regard to NA function and that neurochemical variation is closely associated with differences in clinical characteristics of the children.

Development, Reliability, and Validity of the Children's Aggression Scale-Parent Version

OBJECTIVE To provide preliminary psychometric data on the Childrens Aggression Scale-Parent Version (CAS-P), which assesses severity, frequency, pervasiveness, and diversity of aggressive, as distinct from nonaggressive, disruptive behaviors. METHOD The scale has 33 items representing five domains: Verbal Aggression, Aggression Against Objects and Animals, Provoked Physical Aggression, Unprovoked Physical Aggression, and Use of Weapons. The CAS-P was completed for 73 clinically referred children. Validity was evaluated dimensionally by examining the relationship of CAS-P scores to other parent and teacher rating scales, and categorically by comparing scores of children with attention-deficit hyperactivity disorder (ADHD) alone, oppositional defiant disorder, and conduct disorder. RESULTS The scale as a whole had excellent internal consistency (alpha = .93). Children with conduct disorder were rated significantly higher than those with oppositional defiant disorder, who were rated significantly higher than those with ADHD alone. The CAS-P did not distinguish clinical control children from those with ADHD only. Correlations with other rating scales provide further support for the validity of the CAS-P. CONCLUSIONS The CAS-P assesses distinct components of aggressive behavior and may fill a gap in that it distinguishes among various types and severity of aggressive behaviors, and the settings in which they take place.

ADHD, Aggression, and Antisocial Behavior across the Lifespan

Abstract: The progression to adult antisocial behavior is the least desirable developmental trajectory for children with ADHD. An unremitting pattern of physical aggression appears of great import when predicting long‐term outcome. However, a profile characterized by behavioral and cognitive impulsivity and emotional lability may indicate a greater likelihood of the progression to adult antisocial behavior and violent impulse‐control disorders. This constellation of behaviors appears to be, at least in part, mediated by brain serotonergic systems. The contribution of cognitive impairments, as manifested by executive function deficits, diminished moral reasoning, and impaired empathic ability, to the emergence and persistence of antisocial behavior has yet to be discerned.

ADHD and Reading Disabilities: A Cluster Analytic Approach for Distinguishing Subgroups

Data suggest that children with reading disability (RD) and non-RD children with attention-deficit/hyperactivity disorder (ADHD) may comprise distinct subgroups. Research has been hampered by variance in definitional criteria, which results in the study of different subgroups of children. Using cluster analysis, this study empirically divided children with ADHD (N = 54), based on their Full Scale IQ (FSIQ) and reading ability. Four distinct subgroups emerged in which cognitive, behavioral, and neurochemical function was compared. Cluster 1 was of average FSIQ and reading scores; Cluster 2 was of average FSIQ but showed impairment in reading; Cluster 3 had high FSIQ and reading scores; and Cluster 4 had low scores in both domains. The groups had different patterns of cognitive, behavioral, and neurochemical function, as determined by discrepancies in Verbal-Performance IQ, academic achievement scores, parent aggression ratings, and a measure of noradrenergic function. These distinctions are discussed with regard to etiology, treatment, and long-term outcome.

Attention, Response Inhibition, and Activity Level in Children: Developmental Neuropsychological Perspectives

Injury to the brain early in life frequently leads to a variety of cognitive and behavioral disturbances. The most common of these are mental retardation, deficits in linguistic, perceptual, motor, and attentional functioning, overactivity, and inhibitory control problems. Factors that have been implicated in causing early brain injury include, but are not limited to, perinatal anoxia or hypoxia, exposure to environmental toxins, infections, and malnutrition. Yet, it is noteworthy that many children present with the above problems in the absence of known neurologic insult.

Relationship between central serotonergic function and aggression in prepubertal boys: effect of age and attention-deficit/hyperactivity disorder

Data indicate that diminished central serotonergic (5-HT) function is related to aggression in adults, but discrepant findings in children suggest that age or the presence of attention-deficit/hyperactivity disorder (ADHD) may influence this relationship. This study examined whether age or ADHD affects the association between 5-HT and aggression in 7-11-year old clinically-referred boys. Forty-six boys were divided into non-aggressive ADHD, aggressive ADHD, and aggressive non-ADHD groups based on responses to interviews and ratings of behavior. Central 5-HT function was assessed by measuring the prolactin response to a 1-mg/kg oral dose of D,L-fenfluramine. There was no significant difference in the prolactin response across the three groups of boys. Furthermore, when examined dimensionally, prolactin response was largely unrelated to ratings of aggression, even after controlling for ADHD. Finally, age was not associated with prolactin response, and had no effect on the relationship between prolactin response and aggression. This study provides further evidence that there is no clear relationship between central 5-HT function and aggression in disruptive boys. Moreover, these data do not confirm the hypothesis that age or the presence of ADHD influence the relationship between 5-HT and childhood aggression.