Kjell Tore Hovik

Symptoms of ADHD in children with high-functioning autism are related to impaired verbal working memory and verbal delayed recall.

Symptoms similar to those found in Attention-Deficit/Hyperactivity Disorder (ADHD) often occur in children with Autism Spectrum Disorders (ASD). The objective of the current study was to compare verbal working memory, acquisition and delayed recall in children with High-Functioning Autism (HFA) to children with ADHD and typically developing children (TDC). Thirty-eight children with HFA, 79 with ADHD and 50 TDC (age 8–17) were assessed with a letter/number sequencing task and a verbal list-learning task. To investigate the possible influence of attention problems in children with HFA, we divided the HFA group into children with (HFA+) or without (HFA−) “attention problems” according to the Child Behaviour Checklist 6–18. The children with HFA+ displayed significant impairment compared to TDC on all three neurocognitive measures, while the children with HFA− were significantly impaired compared to TDC only on the working memory and acquisition measures. In addition, the HFA+ group scored significantly below the HFA− group and the ADHD group on the verbal working memory and delayed recall measures. The results support the proposition that children with HFA+, HFA−, and ADHD differ not only on a clinical level but also on a neurocognitive level which may have implications for treatment.

RCT of Working Memory Training in ADHD: Long-Term Near-Transfer Effects

Objective The aim of the study is to evaluate the long-term near-transfer effects of computerized working memory (WM) training on standard WM tasks in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Method Sixty-seven children aged 10–12 years in Vestfold/Telemark counties (Norway) diagnosed with F90.0 Hyperkinetic disorder (ICD-10) were randomly assigned to training or control group. The training group participated in a 25-day training program at school, while the control group received treatment-as-usual. Participants were tested one week before intervention, immediately after and eight months later. Based on a component analysis, six measures of WM were grouped into composites representing Visual, Auditory and Manipulation WM. Results The training group had significant long-term differential gains compared to the control group on all outcome measures. Performance gains for the training group were significantly higher in the visual domain than in the auditory domain. The differential gain in Manipulation WM persisted after controlling for an increase in simple storage capacity. Conclusion Systematic training resulted in a long-term positive gain in performance on similar tasks, indicating the viability of training interventions for children with ADHD. The results provide evidence for both domain-general and domain-specific models. Far-transfer effects were not investigated in this article. Trial Registration: Controlled-Trials.com ISRCTN19133620

Few differences in hot and cold executive functions in children and adolescents with combined and inattentive subtypes of ADHD

The aim of the study was to compare executive processes with pronounced (hot) and less pronounced (cold) emotional salience in medication naïve children and adolescents with ADHD-combined (ADHD-C) and ADHD-inattentive (ADHD-I) subtypes. Thirty-six subjects with ADHD-C, 44 with ADHD-I, and 50 healthy controls between 8 and 17 years were assessed with laboratory tests and inventory-based scales assessing hot and cold executive functions (EF) (controlled attention, working memory, planning, cognitive flexibility, verbal fluency, hot decision making) and the Behavior Rating Inventory of Executive Function (BRIEF). The ADHD-C group displayed significantly more impairment compared to the ADHD-I group on the cold BRIEF Inhibition and Monitor scales. There were no significant differences between ADHD subtypes on cold and hot laboratory tests. The hot decision-making task did not correlate with the other cold or hot EF measures. Overall, few EF measures were shown to differentiate between ADHD subtypes nor were there any relationships between the hot decision-making task and the other EF measures, which seems to indicate separate developmental trajectories.

Distinct Patterns of Everyday Executive Function Problems Distinguish Children With Tourette Syndrome From Children With ADHD or Autism Spectrum Disorders

Objective: The aim is to investigate the everyday executive function (EF) in children with Tourette syndrome (TS), Inattentive or Combined presentations of ADHD (ADHD-I/ADHD-C), autism spectrum disorders (ASD), and typically developing children (TDC). Method: Nineteen TS, 33 ADHD-C, 43 ADHD-I, 34 ASD, and 50 TDC participated (8-17 years). Parents completed the Behavior Rating Inventory of Executive Function (BRIEF). Results: TS, ADHD-C, ADHD-I, or ASD were rated with significantly more regulation problems on all scales compared with TDC. Considerable overlap of symptoms between clinical groups made differentiation difficult on individual scales. Scale configurations showed children with TS to have more problems with emotional control (EC) than cognitive flexibility in relation to children with ASD, more problems with EC than inhibitory control in relation to ADHD-C, and more problems with EC than planning/organizing in relation to ADHD-I. Conclusion: Paired BRIEF scales dissociated EF problems in children with TS from children with ADHD-C, ADHD-I, or ASD. Clinical relevance is discussed.

Working memory arrest in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder: Results from a 2-year longitudinal study

The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically developing children (age 9–16 years) were included at baseline and followed up approximately 25 months later. The children were given a letter/number sequencing task to assess verbal working memory. The performance of children with high-functioning autism on verbal working memory did not improve after 2 years, while improvement was observed in children with attention-deficit/hyperactivity disorder and typically developing children. The results indicate a different developmental trajectory for verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. More research is needed to construct a developmental framework more suitable for children with autism spectrum disorder.

Development of Hot and Cold Executive Function in Boys and Girls With ADHD: A 2-Year Longitudinal Study.

Objective: To investigate the development of executive function with pronounced emotional salience (hot EF) and less pronounced emotional salience (cold EF) in boys and girls with ADHD relative to typically developing (TD) children. Method: Seventy-five children with ADHD and 47 TD children were assessed with hot and cold EF tests at baseline and after 2 years. Results: Despite considerable maturation, the ADHD group remained impaired on all cold EF tests relative to TD children after 2 years. There was no effect of gender on cold EF test results. Females with ADHD outperformed TD counterparts on hot EF at baseline. Females with ADHD showed deteriorating hot EF performance, while TD counterparts showed improved hot EF performance across time. Conclusion: Enduring cold EF impairments after 2 years may reflect stable phenotypic traits in children with ADHD. Results indicate divergent developmental trajectories of hot EF in girls with ADHD relative to TD counterparts.

Differences in cognitive control in children and adolescents with combined and inattentive subtypes of ADHD.

The aim of the present study was to investigate the ability of children with attention deficit/hyperactivity disorder-combined subtype (ADHD-C) and predominantly inattentive subtype (ADHD-PI) to direct their attention and to exert cognitive control in a forced attention dichotic listening (DL) task. Twenty-nine, medication-naive participants with ADHD-C, 42 with ADHD-PI, and 40 matched healthy controls (HC) between 9 and 16 years were assessed. In the DL task, two different auditory stimuli (syllables) are presented simultaneously, one in each ear. The participants are asked to report the syllable they hear on each trial with no instruction on focus of attention or to explicitly focus attention and to report either the right- or left-ear syllable. The DL procedure is presumed to reflect different cognitive processes: perception (nonforced condition/NF), attention (forced-right condition/FR), and cognitive control (forced-left condition/FL). As expected, all three groups had normal perception and attention. The children and adolescents with ADHD-PI showed a significant right-ear advantage also during the FL condition, while the children and adolescents in the ADHD-C group showed a no-ear advantage and the HC showed a significant left-ear advantage in the FL condition. This suggests that the ADHD subtypes differ in degree of cognitive control impairment. Our results may have implications for further conceptualization, diagnostics, and treatment of ADHD subtypes.

Cognition, Emotion and Behavior in Children with Tourette’s Syndrome and Children with ADHD-Combined Subtype—A Two-Year Follow-Up Study

Objective This two-year follow-up study investigates the course of and association among measures of cognitive control, focused attention, decision-making and symptom severity (anxiety, depression and behavior) in children and adolescents with Tourette’s Syndrome (TS) or Attention-Deficit/Hyperactivity Disorder-Combined subtype (ADHD-C). Method 19 children with TS, 33 with ADHD-C, and 50 typically developing children (TDC) were examined with a battery of psychometric measures and rating forms at baseline and two-years later. Results All three groups improved likewise in measures of cognitive control over time, whereas only the TDC improved in focused attention. The group of children with TS with comorbidities performed more similar to the children with ADHD-C in cognitive control at T1 and T2, whereas the children with TS without comorbidities performed more similar to the TDC in cognitive control at T1 and T2. In the decision-making task, the children with TS (with or without comorbidities) preferred a safer strategy in selecting advantageous choices than the children with ADHD-C and the TDC at T2. Children with TS and children with ADHD-C showed higher symptoms of anxiety and depression and more problems with emotional control compared with TDC at both time points. Finally, children with ADHD-C self-reported more depression symptoms than those with TS at both assessments. For the TS group, safer decision-making was related to better emotional control, and this relationship was stronger for the TS subgroup without comorbidities. Conclusion This study emphasizes the importance of addressing symptoms of anxiety and depression in children with TS or ADHD-C, identifying the effect of comorbidities in children with TS, and that children with TS or ADHD-C likely differ in their sensitivity to reinforcement contingencies.

Dissociable Response Inhibition in Children With Tourette’s Syndrome Compared With Children With ADHD

Objective: This study investigates whether performance in a verbal response task (Color-Word Interference Test [CWIT]) and a motor response task (Conners’ Continuous Performance Test [CCPT]) discriminates children with Tourette’s Syndrome (TS), ADHD, and typically developing children (TDC). Method: Nineteen children with TS, 79 with ADHD, and 50 with TDC participated (8-17 years). Results: Children with TS committed significantly fewer errors in the verbal response task than those with ADHD. Moreover, children with TS but without ADHD performed better than TDC. Errors in motor task and speed of response did not distinguish between groups. A cautious tendency of response correlated positively with rates of tics in children with TS. Conclusion: Children with TS were superior in inhibiting a prepotent verbal response; however, comorbidity with ADHD in those children negatively influenced performance. Results support the hypothesis that levels of inhibitory control distinguish children with TS, ADHD, and TDC.

Gender Differences in the Relationship Between Changes in ADHD Symptoms, Executive Functions, and Self- and Parent-Report Depression Symptoms in Boys and Girls With ADHD A 2-Year Follow-Up Study

Objective: This study was conducted to investigate the association between changes in ADHD symptoms, executive functions (EFs), and depression symptoms in girls and boys with ADHD over a 2-year period. Method: Thirty-six girls and 39 boys with ADHD, 18 typically developing (TD) girls and 29 TD boys (ages 9-16) were included. Assessments of EFs, ADHD symptoms, and self- and parent-report of depression symptoms were carried out. Results: For girls, a reduction of inattention symptoms was associated with a decline in parent-rated depression symptoms. A reduction in hyperactivity/impulsivity was associated with a reduction in self-rated depression symptoms in boys, and an increase in girls. A reduction in inattention symptoms was associated with a modest increase in self-rated depression symptoms in both boys and girls. Conclusion: Gathering information from both the parents and the child with ADHD is important in determining how gender may be influencing symptom profiles.