Evaluating vigilance deficits in ADHD: a meta-analysis of CPT performance

We meta-analytically review 47 between-groups studies of continuous performance test (CPT) performance in children with attention-deficit/hyperactivity disorder (ADHD). Using a random effects model and correcting for both sampling error and measurement unreliability, we found large effect sizes (δ) for overall performance, but only small to moderate δ for performance over time in the handful of studies that reported that data. Smaller δs for performance over time are likely attributable, in part, to the extensive use of stimuli for which targets and distractors are quite easily differentiated. Artifacts accounted for a considerable proportion of variance among observed δs. Effect sizes reported in previous reviews were significantly attenuated because of the presence of uncorrected artifacts and highlight the necessity of accounting for artifactual variance in future work to determine the amount of true neurocognitive heterogeneity within ADHD. Signal detection theory and diffusion modeling analyses indicated that the ADHD-related deficits were because of decreased perceptual sensitivity (d') and slower drift rates (v). Results are interpreted the context of several recent models of ADHD.     

Effects of two treatment techniques on delay and vigilance tasks with attention deficit hyperactive disorder (ADHD) children.

In this study, we examined the effects of two treatment techniques under on-medication and off-medication conditions on the hyperactive behavior patterns of children. Three groups of subjects were compared: a control group, a behavior modification group, and a cognitive training group. The Gordon Diagnostic System (Gordon, McClure, & Post, 1986) was used to assess the subjects at the initial screening, during treatment without medication, and during treatment with medication. The two medication conditions were counterbalanced during the second and third testing sessions. Results showed that when the cognitive intervention was combined with medication, there was a significant improvement in the subjects' ability to delay impulsive responding. However, no significant effects were seen for sustained vigilance for either the behavioral or cognitive groups. Parents rated children in the cognitive group significantly higher than those in the control group.     

No vigilance deficit found in either young schizophrenic or ADHD subjects

Vigilance deficits have been found in both schizophrenic and ADHD subjects. The two patient groups have never been directly compared on any vigilance measure, however. In the present study 20 early-onset schizophrenics were compared to 20 ADHD adolescents on a Degraded Stimulus Continuous Performance Test (DS-CPT). A comparison group of 30 normal adolescents was also included. Results showed no significant differences between the three groups on any of the DS-CPT measures. Different hypotheses are put forth to explain the findings, among them that the task may be insensitive to identifying sustained attention deficits in adolescent populations.     

Predicting Parenting Stress in Families of Children with ADHD: Parent and Contextual Factors

We examined parental ADHD symptoms and contextual (parental education, social support, marital status) predictors of parent domain parenting stress (parental distress) as a function of child ADHD symptoms in a sample of 95 parents of 8 to 12 year-old children with and without ADHD. Parents’ perceptions of parental distress and social support were inversely-related. Parental ADHD symptomatology was the strongest predictor of parental distress of the variables considered. Models using teacher reports of child ADHD symptomatology and oppositionality differed from ones using parent reports, in that child oppositionality was only predictive of parental distress in the parent-report model. A post-hoc analysis showed that child factors did not predict parental distress over and above parent ADHD symptoms and contextual factors. These results suggest that parental ADHD symptomatology and parenting stress reduction should be considered in development of interventions for families of children with ADHD.     

Evaluation of sensorimotor training in children with ADHD

Reduced ability to regulate motor behavior seems to be an essential aspect of Attention-Deficit Hyperactivity Disorder (ADHD) and may reflect deficits in behavioral response inhibition. In this respect, pragmatic clinical experience over the last two decades, in daily practice, training of motor control has played an important role within multimodal treatment approaches, although an adequate proof of its efficacy is still lacking. Therefore, to examine the efficacy of sensorimotor training, 12 children with ADHD (two groups of six) were treated with both sensorimotor training and (as control) cognitive behavioral training using a within-subject cross-over design. Each treatment had a duration of 4 months (20 sessions), yielding a total of 40 sessions for the completed cross-over design. Results showed that Sensorimotor Training improved sensorimotor coordination slightly, while Cognitive Behavioral Training ameliorated cognitive impulse control. Hyperactivity and anxious-depressive/aggressive behavior were markedly reduced by Sensorimotor Training but not by Cognitive Behavioral Training. In conclusion, a combined treatment may be recommended since compensation and regulation of inhibitory deficits in ADHD come into play within the framework of both kinds of training.     

WISC-IV and WISC-III profiles in children with ADHD

Wechsler Intelligence Scale for Children, 3rd and 4th editions (WISC-III n = 586 and WISC-IV n = 118), profiles were compared for children with ADHD and normal intelligence. Mean Verbal Comprehension Index (VCI) and Perceptual Organization/Perceptual Reasoning Index (POI/PRI) scores were significantly higher than Freedom From Distractibility/Working Memory Index (FDI/WMI) and Processing Speed Index (PSI), and Symbol Search was higher than Coding. FDI/WMI and PSI scores were similar on both tests, but VCI and POI/PRI were higher on the WISC-IV than on the WISC-III. Therefore, index discrepancies were greater for the WISC-IV, suggesting that the WISC-IV might be better than the WISC-III in delineating the strengths and weaknesses of children with ADHD. All children in the WISC-IV sample scored lowest on WMI or PSI, whereas only 88% of the WISC-III children scored lowest on FDI or PSI. Thus, the WISC-IV may be more helpful in diagnosing ADHD than the WISC-III.     

Complex prospective memory in children with ADHD.

The ability to remember intentions (prospective memory) is fundamental to the organization of goal-directed actions in everyday life. Successful prospective remembering involves forming, retaining, initiating, and executing an intention. Although previous research has demonstrated prospective memory impairments in children with attention deficit/hyperactivity disorder (ADHD), this has largely focused on the intention initiation and execution stages. In this study, we investigate the performance of 20 children with ADHD and 20 matched controls at each of the four stages of prospective memory, using a computer multitask paradigm. Results suggest that children with ADHD may demonstrate difficulties forming delayed intentions, as indicated by impulsive planning, and that this may have further implications for the retention and implementation of these delayed intentions. While children with ADHD showed comparable multitask switching, this appeared to be at the expense of intention execution as they made more performance errors than controls. Implications for day-to-day functioning are discussed.     

Differentiating between ADHD sub-types on CCPT measures of sustained attention and vigilance

The aim of the study was to test whether sustained attention and vigilance, often considered as the same phenomenon, dissociate on the Conners' Continuous Performance Test, and whether subjects with ADHD-Inattentive type and ADHD-Combined type differ with regard to these measures. Sixty-five healthy controls and 67 subjects with ADHD between 9 and 16 years of age participated in the study. The ADHD-I group performed below control children on Hit Reaction Time Block Change, considered to measure sustained attention and the ADHD-C group scored below controls on Hit Reaction Time Inter-Stimulus-Interval, considered to measure vigilance. Comparing the two clinical groups showed a test by group interaction, with ADHD-I subjects performing below ADHD-C subjects with regard to sustained attention and above ADHD-C subjects with regard to vigilance. Sustained attention on the CCPT correlated specifically with parent and teacher ratings of inattention, but not with ratings of hyperactivity-impulsivity, while vigilance correlated with all symptom ratings.     

An investigation of prospective memory in children with ADHD.

Prospective memory, defined as the ability to follow through on intended behavior, is believed to be subserved by a number of neuroanatomical substrates, but particularly dependent, at least in part, on the frontal lobes. Children with Attention-Deficit Hyperactivity Disorder (ADHD) traditionally have difficulty on tasks dependent on frontal lobe structures. The present study attempted to determine whether children with ADHD are impaired in prospective memory function. Two studies are described that use a new measure of time-based prospective memory, the CyberCruiser (Kerns, 2000), to compare children with ADHD to a control group consisting of participants who were matched in respect to age, gender, and IQ. The results document prospective memory deficits in ADHD. Prospective memory performance correlated significantly with clinical measures of ADHD as assessed by the Conners' Parent Rating Scale (Conners, 1990) Hyperactivity Index, but was unrelated to intellectual ability. Though psychometric measures of attention correlated with prospective memory performance, they did not account for the differences in prospective memory that were observed between the ADHD and control groups.     

Evidence for specificity of ERP abnormalities during response inhibition in ADHD children: A comparison with reading disorder children without ADHD

Executive function and working memory deficits are not only present in ADHD, but also in reading disorder (RD). Here, high-density ERPs were recorded during the Stop Signal Task in 53 children and adolescents: An ADHD-combined type group, a group with RD, and a healthy control group. The ADHD-C group displayed unique abnormalities of the frontal N200. Both healthy controls and RD groups showed a success-related right frontal N200 modulation, which was absent in the ADHD group. Second, for Success Inhibition trials, the ADHD-C had smaller right frontal N200 waves relative to healthy controls, while the RD group did not. In contrast, NoGo-P3 abnormalities were present both in the ADHD-C and RD groups. Impaired early response inhibition mechanisms, indexed by the frontal N200, appear to be limited to ADHD-C. In contrast, deficits in later cognitive control and error monitoring mechanisms, indexed by the NoGo-P3, appear to be present in both conditions.