Diversity and attention deficit hyperactivity disorder

Smooth muscle contraction is regulated primarily by the reversible phosphorylation of myosin triggered by an increase in sarcoplasmic free Ca2+ concentration ([Ca2+]i). Contraction can, however, be modulated by other signal transduction pathways, one of which involves the thin filament-associated protein calponin. The h1 (basic) isoform of calponin binds to actin with high affinity and is expressed specifically in smooth muscle at a molar ratio to actin of 1:7. Calponin inhibits (i) the actin-activated MgATPase activity of smooth muscle myosin (the cross-bridge cycling rate) via its interaction with actin, (ii) the movement of actin filaments over immobilized myosin in the in vitro motility assay, and (iii) force development or shortening velocity in permeabilized smooth muscle strips and single cells. These inhibitory effects of calponin can be alleviated by protein kinase C (PKC)-catalysed phosphorylation and restored following dephosphorylation by a type 2A phosphatase. Three physiological roles of calponin can be considered based on its in vitro functional properties: (i) maintenance of relaxation at resting [Ca2+]i, (ii) energy conservation during prolonged contractions, and (iii) Ca(2+)-independent contraction mediated by phosphorylation of calponin by PKC epsilon, a Ca(2+)-independent isoenzyme of PKC.     

Is attention deficit hyperactivity disorder familial?

Using two sources of data, we review methodologic issues pertinent to family studies of attention deficit hyperactivity disorder to evaluate whether such studies define attention deficit hyperactivity disorder as a familial disorder. We systematically evaluate the relevant literature and provide a detailed overview of the Massachusetts General Hospital family-genetic studies of attention deficit disorder as defined in DSM-III and attention deficit hyperactivity disorder as defined in DSM-III-R. The available literature, and our double-blind, controlled studies indicate that attention deficit disorder and attention deficit hyperactivity disorder are familial. Moreover, the pattern of transmission of comorbid disorders suggests that attention deficit hyperactivity disorder is, from a familial perspective, distinct from anxiety disorders and learning disabilities. In contrast, attention deficit hyperactivity disorder with conduct disorder appears to be a familial subtype, and major depression appears to be a variable expression of the familial predisposition to attention deficit hyperactivity disorder. Although the available literature provides strong evidence for the familial transmission of attention deficit hyperactivity disorder, the mode of transmission requires further clarification. In addition, attention deficit hyperactivity disorder appears to be genetically heterogeneous, indicating that more work is needed to delineate genetically homogeneous subtypes and to describe the range of expression of their underlying genotypes. Family-genetic studies will continue to clarify the etiology and nosology of attention deficit hyperactivity disorder.     

Divided attention in youth-onset psychosis and attention deficit/hyperactivity disorder.

The authors used pupillary dilations to test whether divided attention deficits in youth-onset psychosis and attention deficit/hyperactivity disorder (ADHD) were because of limitations in recruitment of cognitive resources or abnormalities in attention allocation. Eight- to 19-year-olds with youth-onset psychosis or ADHD were administered a divided attention test consisting of an auditory digit span (DS) task and a simple visual response time (RT) task. In 4 conditions, participants performed neither (no task), 1 (DS or RT only), or both tasks (dual). Dependent variables were DS accuracy, RT, and pupillary dilation to digits as an estimate of recruitment of cognitive resources. The authors found no evidence for an abnormal attention strategy in either disorder. Instead, results were consistent with the hypothesis that both clinical groups have limitations in resource recruitment. These limitations were more severe in psychosis than in ADHD. Findings indicate that both clinical groups had difficulties in regulating physiological arousal on a moment-to-moment basis in accordance with task demands. Findings also demonstrate the importance of taking into account difficulties that constrain performance on simple tasks before interpreting impairments on complex tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Injury risk factors in children with attention deficit hyperactivity disorder.

Processes related to injury in children with Attention Deficit Hyperactivity Disorder (ADHD) were examined. Two groups of 7–11-year-old boys (14 ADHD and 16 controls) watched a videotape simulating play activities in order for them to identify risky behaviors and then answered questions about risky scenes. Groups did not differ in ability to identify hazards, but children with ADHD anticipated less severe consequences following risky behavior and reported fewer active methods of preventing injury than did controls. Cognitive factors, including lower expectations of personal risk in hazardous situations and less ability to generate prevention strategies and safety rules, may contribute to increased injury liability in boys with ADHD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asymmetrical hemispheric control of visual-spatial attention in adults with attention deficit hyperactivity disorder.

As neuropsychological mechanisms for attention have been hypothesized to be located in the right hemisphere of the brain, several investigators have begun to conceptualize attention deficit hyperactivity disorder (ADHD)-related attentional deficits as involving right-hemispheric abnormalities. The authors evaluated and compared adult patients diagnosed with ADHD with a non-ADHD group of patients using a chronometric visual-spatial attention task that is sensitive to hemispheric differences in efficiency of information processing. Reaction times across different cuing conditions, cue-target delays, and visual fields were assessed. When participants' attention was misdirected with cues in the right visual field and attention had to be switched to a target on the left visual field, there was a longer delay among ADHD adults than non-ADHD adults, specifically when the interval between the cue and target was 800 ms as compared with 100 ms. This specific pattern of dysfunction was interpreted as a difficulty with maintaining attention possibly associated with anterior attention mechanisms in the right hemisphere. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship of attention deficit hyperactivity disorder and conduct disorder to juvenile delinquency: legal implications

Attention deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) are both disorders of childhood and adolescence that all too frequently extend into adulthood. But just what is the relationship between these two disorders? This study explores the overlap between these two disorders as they relate to juvenile delinquency; both are significant risk factors for the development of antisocial behavior. But there is more significance to the presence or absence of ADHD or CD in later antisocial behavior. Higher levels of defiant and/or aggressive behavior lead to antisocial acts as compared with lower levels of defiance and antisocial acts. Boys diagnosed with ADHD have higher felony rates than normal control boys, yet ADHD is not nearly as strong a predictor of offending behavior as is CD in study subjects. The presence of both CD and ADHD contributes to illegal behavior, and it is likely that early intervention in both disorders will reduce the prevalence of antisocial behavior.     

Families of children with attention deficit hyperactivity disorder: a review

OBJECTIVES: 1) To review the evidence of attention deficit hyperactivity disorder (ADHD) and other conditions in family members (siblings and parents) of children with ADHD and determine the importance of genetic and environmental factors in this condition. 2) To describe the prospective 10-year follow-up of 65 families with ADHD children and 43 families of matched normal controls. 3) To review various studies that have looked at parent-child interactions with ADHD children on and off stimulant medication, and such interactions over time. The paper thus provides an overview of family pathology and functioning of families of ADHD children over time. METHOD: The paper outlines twin, sibling, family and adoption studies with regard to possible genetic and environmental factors in ADHD. It also presents data of a prospective 10-year follow-up of 65 families with ADHD children and 43 families of normal controls. This family study evaluated sociocultural factors, child rearing practices, health of family members and relationships, as well as the parental view of the child's functioning over time. RESULTS: A review of the literature suggests that ADHD has a strong genetic component, but that environmental factors also play an important role. Families of children with ADHD have more problems than families of normal controls, but these problems improve as the child with ADHD grows up and leaves home. Families of ADHD subjects can appreciate positive as well as negative changes in their children over time. Generally, family interactions with children with ADHD are problematic but improve when the child is on medication and when the child becomes an adult. CONCLUSIONS: This condition has strong genetic underpinnings; therefore, diagnosing and treating family members (parents and siblings) as well as the child with ADHD is important in improving parent-child interactions and better long-term outcome for the child and his or her family.     

Discrimination of attention deficit hyperactivity disorder by the continuous performance test

OBJECTIVE: To investigate the Continuous Performance Test in discriminating a group of 56 attention deficit hyperactivity disorder (ADHD) children from 56 school children individually matched for age, sex and social class. METHODOLOGY: The children all completed the Continuous Performance Task (CPT). The mothers and teachers completed a Conners Parent-Teacher Rating Scale for the clinic children. RESULTS: The ADHD sample was selected so that the average IQ was 99.8 to match the school sample. A non-parametric discriminant function showed that the subtests of the CPT that best discriminated ADHD were age-normalized errors of commission (NCPTC) and age-normalized mean reaction time (NMNRT). CONCLUSION: Optimal use of the CPT for discrimination of ADHD should include age normalization and mean reaction time to targets. Further evoked potential studies may show brief cortical events involved in reaction time over the course of the CPT, and the processes involved in behavioural control.     

Contrasting cognitive deficits in attention deficit hyperactivity disorder versus reading disability.

Compared 2 common and sometimes comorbid developmental disorders, reading disability (RD) and attention deficit hyperactivity disorder (ADHD), in 2 cognitive domains, phonological processes (PPs) and executive functions (EFs). Ss were 70 boys of early school age, studied by means of a 2 (RD vs no RD)?×?2 (ADHD vs no ADHD)?×?2 (domain type) mixed-model design. The 2 RD groups (RD-only and RD plus ADHD) were significantly impaired compared with both the control and ADHD-only groups on a PP composite score but performed normally on the EF composite score. The ADHD-only group had an opposite profile and was significantly different from both RD groups and from controls on the EF composite score. Thus, there was a double-dissociation between the RD-only and ADHD-only groups. The comorbid group resembled the RD-only group, consistent with the hypothesis that their ADHD symptoms are secondary to RD. These results provide evidence for the separability of PPs from EFs, as well as 1 explanation for the comorbidity between RD and ADHD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thyroid function in a population of children with attention deficit hyperactivity disorder

4-Fluoro-3-nitrobenzoic acid attached to a solid support was shown to react under mild conditions with a wide range of functionalized phenols to yield, after cleavage, the corresponding biaryl ethers in excellent purity. In a similar fashion, biaryl thioethers could be obtained. Further elaboration of immobilized biaryl ethers demonstrates the potential for combinatorial library generation.     

Play therapy with children exhibiting symptoms of attention deficit hyperactivity disorder.

Sixty elementary school age children qualified as symptomatic of attention deficit/hyperactivity disorder (ADHD) were randomly assigned to 1 of 2 treatment conditions: child-centered play therapy (CCPT) or reading mentoring (RM). All children participated in 16 individual 30-min sessions in the schools. Results indicated that children who participated in 16 sessions of CCPT and RM demonstrated statistically significant improvement on the ADHD and student characteristics domains, as well as the Anxiety/Withdrawal and Learning Disability subscales of the Index of Teaching Stress and the ADHD Index of the Conners Teacher Rating Scale--Revised: Short Form. Children who participated in CCPT demonstrated statistically significant improvement over RM children on the student characteristics domain and on the Emotional Lability and Anxiety/Withdrawal subscales of the Index of Teaching Stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An open trial of venlafaxine in adult patients with attention deficit hyperactivity disorder

Stimulant medications are the most widely accepted treatment of attention deficit hyperactivity disorder (ADHD) in spite of controversy over their use. Stimulants have consistently been shown to potentiate noradrenergic brain transmission, a property also characteristic of the recently marketed antidepressant venlafaxine. Eighteen adults who met the Utah Criteria for ADHD in adults were enrolled in an open trial of venlafaxine. Progress was monitored with a recently refined rating scale designed to measure change in adult patients with ADHD. Among the 11 patients who could tolerate the medication, 8 showed a good response that was well maintained. They responded to dosages of 50 to 150 mg/day, with an average dose of 96 mg. Seven of the 18 had difficulty tolerating venlafaxine's side effects. These data suggest that controlled trials should be conducted with venlafaxine for ADHD.     

Time perception and reproduction in young adults with attention deficit hyperactivity disorder.

Adults with attention deficit hyperactivity disorder (ADHD; n ?=? 104) were compared with a control group (n ?=? 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than did the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment and diagnosis of attention deficit/hyperactivity disorder in pediatric general practice

Thorough assessment is a critical first step in the treatment of any psychiatric disorder. The need for rigorous assessment procedures is underscored for those disorders, such as Attention Deficit/Hyperactivity Disorder (ADHD) of childhood, that have a high comorbidity with other common psychiatric disorders, including childhood depression and anxiety. Extensive research regarding diagnostic procedures for ADHD has demonstrated the importance of obtaining assessment data from multiple informants and in multiple modalities as a way of confirming ADHD diagnoses. This article describes how a physician in general pediatric practice might execute a thorough initial and follow-up assessment of a child's ADHD symptomology.     

Trauma exposure among children with oppositional defiant disorder and attention deficit–hyperactivity disorder.

Consecutive admissions to an outpatient child psychiatry clinic diagnosed with oppositional defiant disorder (ODD), attention deficit-hyperactivity disorder (ADHD), or adjustment disorder were assessed for trauma exposure by a structured clinical interview and parent report. Controlling for age, gender, severity of internalizing behavior problems, social competence, family psychopathology, and parent–child relationship quality (assessed by parent report), an ODD diagnosis, with or without comorbid ADHD, was associated with increased likelihood of prior victimization (but not nonvictimization) trauma. ADHD alone was not associated with an increased likelihood of a history of trauma exposure Traumatic victimization contributed uniquely to the prediction of ODD but not ADHD diagnoses. Children in psychiatric treatment who are diagnosed with ODD, but not those diagnosed solely with ADHD, may particularly require evaluation and care for posttraumatic sequelae. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociation of sensitivity and response bias in children with attention deficit/hyperactivity disorder during central auditory masking.

Forty-three children (ages 7.0-14.5 years old) with and without attention deficit/hyperactivity disorder (ADHD), combined type had thresholds for detection of a 500-Hz pure tone estimated with and without a noise masker in the contralateral ear. The ear receiving the signal in the masked condition was varied randomly. A single-interval maximum-likelihood method estimated thresholds and false-alarm rate. Whereas the increase in threshold in children with ADHD in the presence of contralateral masking was comparable with controls, the increase in false-alarm rate was significantly greater. This dissociation between changes in sensitivity and response bias in the presence of masking noise supports suggestions that children with ADHD have difficulty inhibiting maladaptive responses and indicates that this deficit is quantifiable using psychoacoustic methods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Advancing the spontaneous hypertensive rat model of attention deficit/hyperactivity disorder.

To advance the spontaneous hypertensive rat (SHR) model of attention deficit/hyperactivity disorder (ADHD), experiments examined the SHR in tasks recognized to assess functioning of the prefrontal cortex or dorsal striatal. Tasks included odor-delayed win-shift (nonspatial working and reference memory), win-stay (habit learning), and attentional set-shifting (attention and behavioral flexibility). In Experiment 1, the SHR strain was compared with Wistar-Kyoto (WKY) and Wistar-Kyoto Hypertensive (WKHT) strains on the first 2 tasks. In Experiment 2, oral methylphenidate (1.5 mg/kg) and vehicle (water) were evaluated on all 3 tasks in SHR and WKY strains. Results demonstrated that the SHR made significantly more errors in the odor-delayed win-shift, win-stay, and attentional set-shifting tasks compared with the WKY. Similar performances in the WKY and WKHT indicated that deficits observed in the SHR were not related solely to hypertension. Treating the SHR with methylphenidate eliminated strain differences in all 3 tasks. These findings provide evidence that the SHR is a valid model for studying ADHD-associated neurocognitive deficits. Moreover, the current behavioral approach is appropriate to assess novel medications developed to target ADHD-associated neurocognitive deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Outcome of parent-mediated treatment of preschoolers with attention deficit disorder with hyperactivity.

Despite the early onset of attention deficit disorder with hyperactivity (ADDH), there is a dearth of treatment studies with preschoolers with this disorder. Forty-six families with ADDH preschoolers were randomly assigned to either an immediate or a delayed group parent training program aimed at improving child compliance. Groups were balanced on demographic variables. Treatment outcome was evaluated by comparing the groups at pre- and posttreatment and 3-month follow-up on measures of parent–child interactions during free play, a compliance task, and parent-supervised activities, as well as on parent-completed Conners Hyperkinesis Index (C. H. Goyette et al; see record 1980-22450-001) scores. Positive treatment effect was obtained on measures of compliance, parental style of interaction, and management skills. These improvements were maintained at 3-month follow-up. Evaluation of treatment effects on nontargeted child behaviors indicated no generalization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)