Time-based prospective memory difficulties in children with ADHD and the role of time perception and working memory

Time-based prospective memory (PM) is the ability to remember to perform an intended action at a given time in the future. It is a competence that is crucial for effective performance in everyday life and may be one of the main causes of problems for individuals who have difficulty in planning and organizing their life, such as children with attention deficit/hyperactivity disorder (ADHD). This study systematically examines different aspects of time-based PM performance in a task that involves taking an action at a given future time in a group of 23 children with ADHD who were compared with a matched group of typically-developing (TD) children. The children were asked to watch a cartoon and then answer a questionnaire about its content (ongoing task). They were also asked to press a key every 2 minutes while watching the cartoon (PM task). The relationships of time perception and verbal working memory with PM performance were examined by administering appropriate tasks. The results showed that the children with ADHD were less accurate than the TD children in the PM task and exhibited less strategic time-monitoring behavior. Time perception was found to predict PM accuracy, whereas working memory was mainly involved in time-monitoring behavior, but this applied more to the TD group than to the ADHD group, suggesting that children with ADHD are less able to use their cognitive resources when meeting a PM request.     

An Investigation into the Relationship Among ADHD Symptomatology,Creativity, and Neuropsychological Functioning in Children

This paper examined the relationship between creativity and ADHD symptomatology. First, the presence of ADHD symptomatology within a creative sample was explored. Secondly, the relationship between cognitive functioning and ADHD symptomatology was examined by comparing four groups, aged 10–12 years: 1) 29 ADHD children without creativity, 2) 12 creative children with ADHD symptomatology, 3) 18 creative children without ADHD symptomatology, and 4) 30 controls. Creativity, intelligence, processing speed, reaction time, working memory, and inhibitory control were measured. Results showed that 40% of the creative children displayed clinically elevated levels of ADHD symptomatology, but none met full criteria for ADHD. With regard to cognitive functioning, both ADHD and creative children with ADHD symptoms had deficits in naming speed, processing speed, and reaction time. For all other cognitive measures the creative group with ADHD symptoms outperformed the ADHD group. These findings have implications for the development and management of creative children.     

An investigation into the relationship among ADHD symptomatology, creativity, and neuropsychological functioning in children.

This paper examined the relationship between creativity and ADHD symptomatology. First, the presence of ADHD symptomatology within a creative sample was explored. Secondly, the relationship between cognitive functioning and ADHD symptomatology was examined by comparing four groups, aged 10-12 years: 1) 29 ADHD children without creativity, 2) 12 creative children with ADHD symptomatology, 3) 18 creative children without ADHD symptomatology, and 4) 30 controls. Creativity, intelligence, processing speed, reaction time, working memory, and inhibitory control were measured. Results showed that 40% of the creative children displayed clinically elevated levels of ADHD symptomatology, but none met full criteria for ADHD. With regard to cognitive functioning, both ADHD and creative children with ADHD symptoms had deficits in naming speed, processing speed, and reaction time. For all other cognitive measures the creative group with ADHD symptoms outperformed the ADHD group. These findings have implications for the development and management of creative children.     

Attention deficit hyperactivty disorder in Korean juvenile delinquents

This study was conducted to identify attention deficit hyperactivity disorder (ADHD) in Korean juvenile delinquents. Intelligence tests (KEDI-WISC, K-WAIS), the Test of Variables of Attention (TOVA), the Teacher Report Form (TRF), the Youth Self-Report (YSR), and the Rosenberg Self-Esteem Scale were administered to 98 incarcerated Korean adolescents (the delinquent group) and 84 adolescent nondelinquents (the control group). The groups were compared, and significant differences were found for ADHD; 42.4% of the adolescents in the delinquent group were identified as having ADHD, in comparison to 11.9% of the adolescents in the control group. Delinquent adolescents and adolescents with ADHD were found to have lower IQ scores, poorer TOVA performance, more severe problem behaviors, and lower self-esteem than nondelinquent adolescents and adolescents without ADHD. Delinquent adolescents with ADHD consistently fared the worst on assessments of intelligence, TOVA performance, problem behaviors, and self-esteem.     

A Clinical Comparative Study Evaluating the Effect of Epilepsy Versus Adhd on Timed Cognitive Tasks in Children

Both children with epilepsy and children with ADHD may be characterized by slowing on reaction-time measurement. This is of particular interest, as neuropsychological assessment is often requested in the differential diagnosis between children with short non-convulsive epileptic seizures and children with ADHD. In this study we attempt to identify patterns of impairment on timed tasks that are specific for epilepsy, relative to ADHD. This study was an open, controlled parallel-group clinical investigation which included two groups of patients: 60 children with ADHD and 60 children with epilepsy. These children were compared with a control group (n =30) on two types of timed cognitive tasks: tasks with low information load (simple reaction-time measurement) and tasks with high information load (multiple decision reaction-time measurement). The simple reaction-time measurements show significant differences between ADHD and controls (all except for visual RT non-dominant hand) and between epilepsy and controls (only one test). No significant differences were found between epilepsy and ADHD. The two tests with high information load show significant slowing compared with the controls for epilepsy on the Binary Choice Reaction-Time Test and for ADHD on the Visual Searching Test. On both tests also the differences between epilepsy and ADHD are significant. The two tests in combination have a relatively satisfactory potential to classify the children with ADHD (75% correct classification) and the children with epilepsy (55% correct classification). We may conclude that complex reaction-time tests (i.e., timed tasks with high information load) have potential for assessing the differential impact of ADHD and epilepsy on attentional function. These tasks specifically reveal general slowing for children with epilepsy and slowing as an effect of failures of inhibitory self control on unstructured tasks for ADHD.     

A clinical comparative study evaluating the effect of epilepsy versus ADHD on timed cognitive tasks in children.

Both children with epilepsy and children with ADHD may be characterized by slowing on reaction-time measurement. This is of particular interest, as neuropsychological assessment is often requested in the differential diagnosis between children with short non-convulsive epileptic seizures and children with ADHD. In this study we attempt to identify patterns of impairment on timed tasks that are specific for epilepsy, relative to ADHD. This study was an open, controlled parallel-group clinical investigation which included two groups of patients: 60 children with ADHD and 60 children with epilepsy. These children were compared with a control group (n=30) on two types of timed cognitive tasks: tasks with low information load (simple reaction-time measurement) and tasks with high information load (multiple decision reaction-time measurement). The simple reaction-time measurements show significant differences between ADHD and controls (all except for visual RT non-dominant hand) and between epilepsy and controls (only one test). No significant differences were found between epilepsy and ADHD. The two tests with high information load show significant slowing compared with the controls for epilepsy on the Binary Choice Reaction-Time Test and for ADHD on the Visual Searching Test. On both tests also the differences between epilepsy and ADHD are significant. The two tests in combination have a relatively satisfactory potential to classify the children with ADHD (75% correct classification) and the children with epilepsy (55% correct classification). We may conclude that complex reaction-time tests (i.e., timed tasks with high information load) have potential for assessing the differential impact of ADHD and epilepsy on attentional function. These tasks specifically reveal general slowing for children with epilepsy and slowing as an effect of failures of inhibitory self control on unstructured tasks for ADHD.     

Validity of the Brown ADD scales: an investigation in a predominantly inattentive ADHD adolescent sample with and without reading disabilities

The Brown ADD Scale for Adolescents is widely used in clinical settings, yet, no published studies have investigated divergent and concurrent validity and specificity and sensitivity to inattentive ADHD symptomatology. Ninety-eight participants (13 to 16 years) were classified as ADHD/I and/or reading disabled (RD) using Kiddie Schedule for Affective Disorder and Schizophrenia (K-SADS), Conners' Rating Scales (CRS-R), and Ontario Child Health Study Scales (OCHSS), WRAT3, and WRMT-R. The results were: 29 ADHD/I; 12 RD, 16 ADHD/I with RD; and, 41 controls. The RD group was included to evaluate specificity. The Brown was administered but not used in classification. The ADHD groups scored higher on the Brown subscales compared with the other two groups. The recommended cutoffs resulted in high rates of false negatives but few false positives; this suggests good specificity but poor sensitivity. There were moderate correlations among the Brown, CRS-R, and OCHSS. The Brown can be useful in screening out ADHD; however, its low sensitivity precludes its usefulness in diagnosing ADHD.     

A critical appraisal of the role of neuropsychological deficits in preschool ADHD

The present study aimed at improving our understanding of the role of neuropsychological deficits in preschool Attention Deficit Hyperactivity Disorder (ADHD). The study included 52 children in the ADHD group and 72 controls (age 4–6 years). Both laboratory measures and teacher reports of executive deficits (i.e., working memory, inhibition, and shifting), delay-related behaviors (i.e., the preference for minimizing delay), and emotional functions (i.e., emotion recognition and regulation) were included. Variable-oriented analyses were complemented with person-oriented analyses (i.e., identifying the proportion of patients considered impaired). Results showed that the ADHD group differed from controls with regard to all measures of executive functioning and most measures of delay-related behaviors, but few differences were found for emotional functioning. A substantial subgroup (23%) of children with ADHD did not have a neuropsychological deficit in any domain. There were subgroups with executive or delay-related deficits only, but no pure emotional subgroup. The overlap between different neuropsychological deficits was much larger when teacher reports were used as opposed to laboratory measures. Regarding functional impairments, large mean differences were found between the ADHD group and controls. However, neuropsychological deficits were not able to explain individual variations in daily life functioning among children with ADHD. In conclusion, the present study identified some important methodological and theoretical issues regarding the role of neuropsychological functioning in preschool ADHD.     

Executive functions in kindergarteners with high levels of disruptive behaviours

Executive function (EF) deficits have yet to be demonstrated convincingly in children with disruptive behaviour disorders (DBD), as only a few studies have reported these. The presence of EF weaknesses in children with DBD has often been contested on account of the high comorbidity between DBD and attention‐deficit/hyperactivity disorder (ADHD) and of methodological shortcomings regarding EF measures. Against this background, the link between EF and disruptive behaviours in kindergarteners was investigated using a carefully selected battery of EF measures. Three groups of kindergarteners were compared: (1) a group combining high levels of disruptive behaviours and ADHD symptoms (COMB); (2) a group presenting high levels of disruptive/aggressive behaviours and low levels of ADHD symptoms (AGG); and (3) a normative group (NOR). Children in the COMB and AGG groups presented weaker inhibition capacities compared with normative peers. Also, only the COMB group showed weaker working memory capacities compared with the NOR group. Results support the idea that preschool children with DBD have weaker inhibition capacities and that this weakness could be common to both ADHD and DBD.     

Attentional WM is not necessarily specifically related with fluid intelligence: the case of smart children with ADHD symptoms

Executive functions and, in particular, Attentional (active) Working Memory (WM) have been associated with fluid intelligence. The association contrasts with the hypothesis that children with ADHD exhibit problems with WM tasks requiring controlled attention and may have a good fluid intelligence. This paper examines whether children who are intelligent but present ADHD symptoms fail in attentional WM tasks. The latter result would be problematic for theories assuming the generality of a strict relationship between intelligence and WM. To study these issues, a battery of tests was administered to a group of 58 children who all displayed symptoms of ADHD. All children were between the age of 8 and 11 years, and were described by their teachers as smart. Children were compared to a control group matched for age, schooling, and gender. The battery included a test of fluid intelligence (Raven’s Coloured Matrices), and a series of visuospatial WM tasks. Results showed that children with ADHD were high in intelligence but significantly lower than the controls in WM tasks requiring high attentional control, whereas there was no difference in WM tasks requiring low attentional control. Furthermore, only high attentional control WM tasks were significantly related to Raven’s performance in the control group, whereas all WM tasks were similarly related in the ADHD group. It is concluded that performance in high attentional control WM tasks may be related to fluid intelligence, but also to a specific control component that is independent of intelligence and is poor in children with ADHD.     

Variations in Anxiety and Depression as a Function of ADHD Subtypes Defined by DSM-IV: Do Subtype Differences Exist or Not?

Concerns have been raised about the ability of diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD) to distinguish subtypes that are clearly distinct from each other with regard to clinical correlates. One area of concern is that research regarding differences in anxiety and depression as a function of ADHD subtype has produced discrepant findings. This study was designed to systematically evaluate whether the ADHD subtypes differ with regard to level of internalizing symptoms. From a large pool of children referred to an ADHD center based in a pediatric hospital, children were differentiated into three groups: ADHD, Combined Type (ADHD/COM); ADHD, Inattentive Type (ADHD/I); and a non-ADHD, comparison group (COMP). Parent- and child-report measures using both dimensional and categorical methods were used to assess internalizing symptoms. The results indicated that children with ADHD/COM and ADHD/I had similar levels of anxiety and depression. Subtype differences related to parent-reported depression were accounted for by group differences in level of externalizing problems. The results were discussed with regard to their implications for refining the criteria used to differentiate children with ADHD into subtypes.     

Differences in feedback- and inhibition-related neural activity in adult ADHD

The objective of this study was to examine response inhibition- and feedback-related neural activity in adults with attention deficit hyperactivity disorder (ADHD) using event-related functional MRI. Sixteen male adults with ADHD and 13 healthy/normal controls participated in this study and performed a modified Go/NoGo task. Behaviourally, attention and inhibition problems in the ADHD group were observed; no feedback-related differences between the groups were detected. The neuroimaging data showed that the ADHD group displayed more activation in the inferior frontal gyrus and putamen during response inhibition. During feedback-related processes, the ADHD group displayed less activation in the inferior frontal/orbitofrontal cortex, hippocampus/nucleus accumbens, and caudate nucleus, but more activity in the inferior frontal gyrus. These results indicate that at least two distinguishable underlying brain networks related to response inhibition and feedback are altered in adults with ADHD.     

Delay discounting of monetary gains and losses in adolescents with ADHD: Contribution of delay aversion to choice

Adolescents with attention-deficit/hyperactivity disorder (ADHD) are known to have stronger preferences for smaller immediate rewards over larger delayed rewards in delay discounting tasks than their peers, which has been argued to reflect delay aversion. Here, participants performed a delay discounting task with gains and losses. In this latter condition, participants were asked whether they were willing to wait in order to lose less money. Following the core assumption of the delay aversion model that individuals with ADHD have a general aversion to delay, one would predict adolescents with ADHD to avoid waiting in both conditions. Adolescents (12–17 years) with ADHD (n = 29) and controls (n = 28) made choices between smaller immediate and larger delayed gains, and between larger immediate and smaller delayed losses. All delays (5–25 s) and gains/losses (2–10 cents) were experienced. In addition to an area under the curve approach, a mixed-model analysis was conducted to disentangle the contributions of delay duration and immediate gain/delayed loss amount to choice. The ADHD group chose the immediate option more often than controls in the gain condition, but not in the loss condition. The contribution of delay duration to immediate choices was stronger for the ADHD group than the control group in the gain condition only. In addition, the ADHD group scored higher on self-reported delay aversion, and delay aversion was associated with delay sensitivity in the gain condition, but not in the loss condition. In sum, we found no clear evidence for a general aversion to delay in adolescents with ADHD.     

Review of the Evidence for Motivation Deficits in Youth with ADHD and Their Association with Functional Outcomes

Preeminent theories of attention-deficit/hyperactivity disorder (ADHD) suggest that motivation deficits are core underlying features of the disorder. However, it is currently unclear whether empirical evidence supports the assertion that significant group (ADHD v. comparison) differences in motivation exist or that problems with motivation contribute to the functional impairments that youth with ADHD experience. Accordingly, this review focused on evaluating and summarizing the empirical literature on the presence of motivation deficits and their association with functional outcomes in samples of youth with ADHD. Twenty studies met the review inclusion criteria. Results support the assertion that youth with ADHD have lower academic-related motivation in comparison to their peers and that motivation plays an important role in academic outcomes, with the strongest evidence to date for reading achievement. However, the available evidence is limited, and few existing studies are aligned with the much larger theoretical and empirical motivation literature in typically developing youth. Given preliminary evidence that motivation plays a role in the academic impairments of youth with ADHD, the review concludes with a discussion of whether current ADHD interventions adequately target motivation and highlights important future directions.     

Cognitive Functioning in Adolescents with Self-Reported ADHD and Depression: Results from a Population-Based Study

This study aims to assess cognitive functioning differences among adolescents with retrospectively self-reported: ADHD and an onset of depression, only ADHD, only depression, and neither ADHD nor depression. Data from the Tracking Adolescents’ Individual Lives Survey (TRAILS) cohort was used in this study. Neuropsychological functioning was assessed in 1549 adolescents, at baseline and follow-up (mean ages 11 and 19 years). The Composite International Diagnostic Interview was used to classify adolescents into 4 groups: ADHD with onset of depression, only ADHD, only depression, and neither ADHD nor depression. Linear mixed effects models were used to analyse group differences in cognitive functioning at baseline and follow-up, and the change in cognitive functioning between these 2 time-points. Results showed a significant main effect of group on response time variability at baseline, working memory maintenance at follow up, and change in response time variability scores between baseline and follow-up. As compared to the healthy and depressed-only groups, adolescents with only ADHD showed longer response time variability at baseline and, which declined between baseline and follow-up. Adolescents with ADHD plus depression showed higher reaction time for working memory maintenance than the depressed only and healthy groups at follow-up. In conclusion, adolescents with self-reported ADHD show poorer cognitive functioning than healthy adolescents and those with only depression. Amongst adolescents with ADHD, specific cognitive domains show poor functioning depending on the presence or absence of comorbid depression. While adolescents with only ADHD have lower reaction time variability, those with comorbid depression have poorer working memory maintenance.     

Language and executive functioning skills of students with attention deficit/hyperactivity disorder (ADHD), and in reading comprehension difficulties (RCD)

The aim of this work was to study the specificity of deficits in linguistic and executive functioning of students with ADHD and with RCD and to determine the profile of deficits in the comorbid group (ADHD+RCD). Participants in the study were 84 students, ages 12-16 years divided into four groups with an equal number of subjects (N= 21): ADHD, RCD, ADHD+RCD and comparison group (without ADHD and without RCD). We measured vocabulary, oral comprehension, lexical access, verbal and visual working memory, inhibition and attention. The results show that the ADHD+RCD group presents the most important linguistic deficits, followed by the RCD group. On the other hand, the three clinical groups (ADHD, RCD and ADHD+RCD) display greater performance problems in working memory than the comparison group, whereas the two groups with ADHD had more problems in attention and inhibition. These results suggest the dissociation of linguistic and executive deficits that affect the RCD group and ADHD group to a greater extent, respectively. Lastly, the comorbid group showed deficits both in language and in executive skills. We discuss the implications of these findings for designing interventions.     

Distinguishing sluggish cognitive tempo from attention-deficit/hyperactivity disorder in adults

Researchers who study subtypes of attention-deficit/hyperactivity disorder (ADHD) in children have identified a subset having a sluggish cognitive tempo (SCT) typified by symptoms of daydreaming, mental confusion, sluggish-lethargic behavior, and hypoactivity, among others who differ in many respects from ADHD. No studies have examined the nature and correlates of SCT in adults. This study sought to do so using a general population sample in which those having high levels of SCT symptoms were identified (≥95th percentile) and compared to adults having high levels of ADHD symptoms and adults having both SCT and ADHD symptoms. From a representative sample of 1,249 U.S. adults 18-96 years four groups were created: (a) high levels of SCT but not ADHD (N = 33), (b) high levels of ADHD but not SCT (N = 46), (c) high levels of both SCT and ADHD (N = 39), and (d) the remaining adults as a control group (N = 1,131). As in children, SCT formed a distinct dimension from ADHD symptoms that was unrelated to age, sex, or ethnicity. Adults in both ADHD groups were younger than those with SCT only or control adults. The SCT-only group had less education than the control group, whereas both SCT groups earned less annual income than the control or ADHD-only group. More individuals in the combined group were out of work on disability. In their EF, both SCT groups reported greater difficulties with self-organization and problem solving than controls or the ADHD-only group. Otherwise, the SCT + ADHD group reported significantly greater problems with all other domains of EF than the other groups. But both the SCT-only and ADHD-only groups had significantly more EF difficulties than controls though not differing from each other. A similar pattern was evident on most ratings of psychosocial impairment, except in work and education where SCT was more impairing than ADHD alone and in driving where ADHD was more impairing. SCT contributed unique variance to EF deficits and psychosocial impairment apart from ADHD inattention and hyperactive-impulsive symptoms. Results further suggested that a symptom threshold of 5 or more out of 9 along with a requirement of impairment would result in 5.1% of the population as having SCT. It is concluded that SCT may be a separate disorder from ADHD yet with comorbidity occurring in approximately half of all cases of each. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Frontal lobe functioning in adolescents with attention deficit hyperactivity disorder

A prominent hypothesis regarding the etiology of attention deficit hyperactivity disorder (ADHD) is that its presence and magnitude reflect frontal lobe dysfunction. Past tests of this hypothesis have been inconsistent. The present study examined frontal lobe functioning in adolescents with ADHD. A sample of 10 ADHD adolescents and 10 controls between the ages of 12 and 17 served as participants for the study. The control group was matched on age (within six months) and gender. This study aided in clarifying past contradictory studies by using clearly defined criteria to determine ADHD, a representative age range of participants, carefully selected tests, and a control task. The two measures that were administered to assess frontal lobe functioning were the Wisconsin Card Sorting Test and the Stroop Color and Word Test. The Purdue Pegboard was used as a control measure that did not assess frontal lobe functioning. The findings indicate that the ADHD group performed significantly worse on the following: color score, color/word score, and interference score of the Stroop Color and Word Test; percent of perseverative responses, percent of perseverative errors, and number of completed categories of the Wisconsin Card Sorting Test. No differences were found on the Purdue Pegboard task.     

Underlying processes in the poor response inhibition of children with Attention-Deficit/Hyperactivity Disorder

This study evaluated the effects of reward, punishment, and reward + punishment on the impulsive responses of ADHD children. The impulsive responses of ADHD and normal control boys (30 per group) were compared during performance of a go/no-go task, administered under reward-only, punishment-only, and reward + punishment conditions. When differences in aggression, anxiety, and IQ between these groups were controlled for, results indicated that the impulsivity levels of the ADHD group were higher than the control group in all three reinforcement conditions. Also, the ADHD group was more impulsive in the reward + punishment condition, compared to the reward-only and punishment-only conditions, and there was no difference between the reward-only and punishment-only conditions. The control groups showed no difference across the three reinforcement conditions. These findings raise the possibility that the poor response inhibition of ADHD children may be related to both a generalized inhibitory deficit and a response modulation deficit.     

Psychopathological Profile in Children with Chronic Tic Disorder and Co-existing ADHD: Additive Effects

The nature of the co-occurrence of chronic tic disorders (CTD) and attention deficit hyperactivity disorder (ADHD) is unclear. Especially in the field of psychopathology, the relationship of CTD and ADHD remains to be clarified. Thus, the aim of the present chart review study was to specify the contribution of CTD and/or ADHD to the psychopathological profile of the comorbid group (CTD+ADHD). The psychopathological profiles of four large groups (CTD-only (n=112), CTD+ADHD (n=82), ADHD-only (n=129), controls (n=144)) were measured by the eight subscales of the Child Behavior Checklist (CBCL) and analyzed by a 2×2 factorial design followed by contrasts. There were main effects of ADHD diagnosis on all but one subscale of the CBCL (Somatic Complaints). For CTD diagnosis, main effects were found for Attention Problems, Anxious/Depressed, Thought Problems, Social Problems and Somatic Complaints. The only interaction effect was seen for Somatic Complaints. While CTD and ADHD were both related to internalizing psychopathology of children in the CTD+ADHD group, ADHD had the largest effect on externalizing psychopathology in the comorbid group. At the level of psychopathology, an additive model for the co-occurrence of CTD and ADHD is strongly supported. In the comorbid group (CTD+ADHD), the ADHD diagnosis shows the strongest relation to externalizing psychopathology.