Normal executive attention but abnormal orienting attention in individuals with sluggish cognitive tempo

Background/objective: Sluggish Cognitive Tempo (SCT) is an attentional disorder characterized by the symptoms of slowness in behavior or thinking, a lack of en.ergy, difficulty initiating and sustaining effort, daydreaming, and drowsiness. The aim of the present study was to investigate the distinctive attentional characteristics of SCT as compared to Attention-Deficit/Hyperactivity Disorder (ADHD). Method: A total of 110 adults were recruited and divided into four groups: SCT+ADHD, SCT, ADHD, and healthy controls. The Revised version of Attention Networks Test was used to investigate each group’s attentional profile. Results: The results revealed that the two SCT groups (SCT+ADHD and SCT) showed a significantly weaker orienting network due to the problems of engaging and disengaging attention than the other two groups. Additionally, the two ADHD groups (SCT+ADHD and ADHD) showed a significantly weaker executive control network than the other two groups. Conclusions: The findings demonstrate an attentional distinction between the SCT and the ADHD groups with a greater dysfunction in the orienting network in the SCT group as compared to the ADHD group. Furthermore, a greater executive control dysfunction was observed in the ADHD group as compared to the SCT group.     

Clinical and functional correlates of processing speed in pediatric Attention-Deficit/Hyperactivity Disorder: a systematic review and meta-analysis

It is well established that processing speed is negatively impacted in children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD). Unfortunately, exactly how processing speed vulnerabilities manifest in daily functioning has not been well established. To support clinical care of youth with ADHD, it is important to better understand the functional consequences and relevant outcomes associated with processing speed deficits. This systematic review and meta-analysis sought to identify the association between processing speed and clinical or functional correlates among children or adolescents diagnosed with ADHD. A total of 409 abstracts were screened, of which, 60 full-text articles were identified as potentially relevant, and 8 of these studies met inclusion criteria. Domains evaluated across these studies included reading skills, mathematics skills, written expression, anxiety, self-appraisals of competence, and adaptive functioning. Six studies reported an association between processing speed and reading skills, allowing for meta-analysis. Processing speed difficulties among youth with ADHD appear strongly associated with several clinical and functional correlates including weaker academic skills, poorer adaptive skills, increased self-reported anxiety, and overestimates of social competence. Meta-analytic results for studies reporting the association between processing speed and reading skills indicate a medium overall weighted mean effect size (r = 0.33, 95% CI = 0.28 –0.39) with minimal heterogeneity (I² = 0.17). Clinical implications of these findings, limitations in the current knowledge base, and suggestions for future research are discussed.     

Treatment Efficacy of Multiple Family Therapy for Chinese Families of Children with Attention Deficit Hyperactivity Disorder

The treatment efficacy of multiple family therapy (MFT) for Chinese families of children with attention deficit hyperactivity disorder (ADHD) has not been studied in the past. In this paper, the effect of MFT on different aspects of the lives of the parents in the experimental group (n = 61) was compared with the effect of only the psychoeducational talks on parents in the control group (n = 53). The results of a MANOVA have shown that by the time they reached the posttreatment phase, the parents who had completed the full 42 hours of the MFT program perceived their children's ADHD symptoms as being less serious and less pathological than they had originally thought compared to the parents in the control group. The effect of MFT on parent–child relationships, parenting stress, parental efficacy, hope, and perceived social support was statistically insignificant. Contributions and limitations of our study are discussed.     

Hyperactivity in boys with attention deficit/hyperactivity disorder (ADHD): The association between deficient behavioral inhibition,attentional processes,and objectively measured activity

Contemporary models of ADHD hypothesize that hyperactivity reflects a byproduct of inhibition deficits. The current study investigated the relationship between children's motor activity and behavioral inhibition by experimentally manipulating demands placed on the limited-resource inhibition system. Twenty-two boys (ADHD = 11, TD = 11) between the ages of 8 and 12 years completed a conventional stop-signal task, two choice-task variants (no-tone, ignore-tone), and control tasks while their motor activity was measured objectively by actigraphs placed on their nondominant wrist and ankles. All children exhibited significantly higher activity rates under all three experimental tasks relative to control conditions, and children with ADHD moved significantly more than typically developing children across conditions. No differences in activity level were observed between the inhibition and noninhibition experimental tasks for either group, indicating that activity level was primarily associated with basic attentional rather than behavioral inhibition processes.     

注意缺陷多动障碍的神经机制及干预

注意缺陷多动障碍是一种常见的神经性、发展性障碍。大脑异常被认为是注意缺陷多动障碍的病因之一。随着脑成像技术的发展,当前对该障碍的脑解剖结构病变、脑神经发育迟缓和脑网络连接异常等方面都展开了深入研究。文章从以上三个方面介绍最新研究成果,并指出目前的不足和未来研究方向,在此基础上为提高诊断精确性和发展新型有效的治疗干预方法提供建议。     

Comorbidity of attention Deficit Hyperactivity Disorder and Post-Traumatic Stress Disorder

Attention Deficit Hyperactivity Disorder (ADHD) and Post-Traumatic Stress Disorder (PTSD) show a high degree of comorbidity in traumatized children. Two hypotheses may help explain this relationship: children with ADHD are at higher risk for trauma due to their impulsivity, dangerous behaviors, and parents who may have a genetic predisposition for impairment of their own impulse control; and hyperarousal induced by severe trauma and manifested by hypervigilance and poor concentration may impair attention to create an ADHD-like syndrome. Four illustrative cases are presented, and implications for treatment are discussed.     

Etiologic Subtypes of Attention-Deficit/Hyperactivity Disorder: Brain Imaging, Molecular Genetic and Environmental Factors and the Dopamine Hypothesis

Multiple theories of Attention-Deficit/Hyper- activity Disorder (ADHD) have been proposed, but one that has stood the test of time is the dopamine deficit theory. We review the narrow literature from recent brain imaging and molecular genetic studies that has improved our understanding of the role of dopamine in manifestation of symptoms of ADHD, performance deficits on neuropsychological tasks, and response to stimulant medication that constitutes the most common treatment of this disorder. First, we consider evidence of the presence of dopamine deficits based on the recent literature that (1) confirms abnormalities in dopamine-modulated frontal-striatal circuits, reflected by size (smaller-than-average components) and function (hypoactivation); (2) clarifies the agonist effects of stimulant medication on dopaminergic mechanisms at the synaptic and circuit level of analysis; and (3) challenges the most-widely accepted ADHD-related neural abnormality in the dopamine system (higher-than-normal dopamine transporter [DAT] density). Second, we discuss possible genetic etiologies of dopamine deficits based on recent molecular genetic literature, including (1) multiple replications that confirm the association of ADHD with candidate genes related to the dopamine receptor D4 (DRD4) and the DAT; (2) replication of differences in performance of neuropsychological tasks as a function of the DRD4 genotype; and (3) multiple genome-wide linkage scans that demonstrate the limitations of this method when applied to complex disorders but implicate additional genes that may contribute to the genetic basis of ADHD. Third, we review possible environmental etiologies of dopamine deficits based on recent studies of (1) toxic substances that may affect the dopamine system in early development and contribute substantially to the etiology of ADHD; (2) fetal adaptations in dopamine systems in response to stress that may alter early development with lasting effects, as proposed by the developmental origins of health and disease hypothesis; and (3) gene-environment interactions that may moderate selective damage or adaptation of dopamine neurons. Based on these reviews, we identify critical issues about etiologic subtypes of ADHD that may involve dopamine, discuss methods that could be used to address these issues, and review old and new theories that may direct research in this area in the future.     

Attention-Deficit/Hyperactivity Disorder: A Neuropsychological Perspective Towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.     

Family Impact of Tourette's Syndrome

Tourette's syndrome (TS) is a neuropsychological disorder characterized by vocal and motor tics. TS is also associated with several behavior disorders such as Attention Deficit Hyperactivity Disorder, Oppositional Defiant Disorder, conduct disorder, and Obsessive-Compulsive Disorder. We examined the impact of Tourette's syndrome with and without comorbid psychiatric disorders on the family. TS complicated by comorbid disorders had a greater impact on the family than uncomplicated TS. Tourette's symptom severity was significantly correlated with the level of impact on the family and with the number of comorbid disorders. TS is a disorder with effects that extend beyond motor and vocal tics.     

Performance and Private Speech of Children with Attention-Deficit/Hyperactivity Disorder While Taking the Tower of Hanoi Test: Effects of Depth of Search,Diagnostic Subtype,and Methylphenidate

We administered the Tower of Hanoi to demographically comparable samples of control participants (n = 34) and children with the Combined (n = 22) and Inattentive subtypes (n = 19) of Attention-Deficit/Hyperactivity Disorder (ADHD). Controls excelled over children with the Inattentive subtype, who outperformed patients with the Combined subtype. These results replicated findings of greater executive deficits in the Combined than in the Inattentive type of ADHD. Double-blind administration of methylphenidate improved task performance only for patients with the Inattentive subtype. In a drug-free Baseline session, children with both subtypes of ADHD made more private verbalizations than controls, particularly when failing puzzles. In later sessions, regardless of drug condition, the inattentive sample exhibited a smaller increase in self-regulatory utterances under failure. In contrast, the combined sample decreased self-regulatory verbalizations under failure only under methylphenidate. The results support some differences between the two subtypes of ADHD in executive functioning and in their response to stimulant therapy. Portions of these results were submitted as part of H. Theresa Chang's PhD dissertation (Chang, 2000) and Helena Kopecky's unpublished master's research, both conducted at the University of Rochester and supervised by Rafael Klorman.