Executive Function in Autism: Association with ADHD and ASD Symptoms.

There is substantial comorbidity between autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD), and there are well-documented executive functioning (EF) deficits in both populations. An important question concerns whether EF deficits in children with ASD are related to severity of ASD, ADHD, or both. We examined ADHD and ASD symptoms in relation to ratings of EF in the home and classroom. The sample comprised 64 children (55 males) diagnosed with ASD (mean age = 9.26 years; mean FSIQ = 92). Analyses indicated that parent and teacher ratings of EF (except Shift and Emotional Control) were consistently related to ADHD symptom severity, but not to ASD severity. Thus, functioning in the domains of Shift and Emotional control appear relatively spared, whereas performance in all other EF was impaired in relation to ADHD symptoms.

Methylphenidate Improves Autonomic Functioning among Youth with Attention-Deficit/Hyperactivity Disorder.

Psychostimulants are commonly prescribed medications for youth with attention-deficit/hyperactivity disorder (ADHD). Limited studies have evaluated how psychostimulants (e.g., methylphenidate [MPH]) impact autonomic nervous system (ANS) indexes among youth with ADHD. Understanding the effects of MPH on autonomic functioning is essential, given that youth with ADHD have been shown to experience atypical autonomic functioning (i.e., reduced activity across both sympathetic and parasympathetic branches) compared to typically developing youth. The current study investigated how a specific psychostimulant, Osmotic Release Oral System [OROS] MPH, impacts parasympathetic (indexed by respiratory sinus arrhythmia [RSA]) and sympathetic (indexed by electrodermal activity [EDA]) functioning among youth with ADHD via a within-subjects, double-masked, cross-over design. Two hundred fifty-six participants (157 youth with ADHD), ages 5 to 13 years, completed a two-minute resting baseline task while electrocardiograph and electrodermal data were obtained. Youth with ADHD completed the resting baseline task twice, 3 weeks apart, once during active medication and once during placebo conditions (counterbalanced). Typically developing youth were assessed without medication or placebo. Youth with ADHD during the placebo condition exhibited reduced RSA and EDA compared to typically developing youth. In contrast, youth with ADHD during the medication condition did not differ significantly from typically developing youth with respect to either RSA nor EDA. As such, OROS MPH appears to normalize RSA and EDA levels among youth with ADHD to levels comparable to typically developing youth. Future studies including indexes of the ANS among youth with ADHD are urged to consider the impact of MPH.

ADHD severity as a predictor of cognitive task performance in children with Autism Spectrum Disorder (ASD).

BACKGROUND: In recent years, a number of studies have begun to explore the nature of Attention-Deficit/Hyperactivity Disorder (ADHD) in children with Autism Spectrum Disorder (ASD). In this study, we examined the relationship between both symptoms of ADHD and symptoms of ASD on cognitive task performance in a sample of higher-functioning children and adolescents with ASD. Participants completed cognitive tasks tapping aspects of attention, impulsivity/inhibition, and immediate memory. AIMS: We hypothesized that children with ASD who had higher levels of ADHD symptom severity would be at higher risk for poorer sustained attention and selective attention, greater impulsivity/disinhibition, and weaker memory. METHODS AND PROCEDURES: The sample included 92 children (73 males) diagnosed with ASD (Mean Age = 9.41 years; Mean Full Scale IQ = 84.2). OUTCOMES AND RESULTS: Using regression analyses, more severe ADHD symptomatology was found to be significantly related to weaker performance on tasks measuring attention, immediate memory, and response inhibition. In contrast, increasing severity of ASD symptomatology was not associated with higher risk of poorer performance on any of the cognitive tasks assessed. CONCLUSIONS AND IMPLICATIONS: These results suggest that children with ASD who have more severe ADHD symptoms are at higher risk for impairments in tasks assessing attention, immediate memory, and response inhibition-similar to ADHD-related impairments seen in the general pediatric population. As such, clinicians should assess various aspects of cognition in pediatric patients with ASD in order to facilitate optimal interventional and educational planning.

Effects of Extended-Release Methylphenidate Treatment on Cognitive Task Performance in Children with Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder.

Objective: To examine the effectiveness of four doses of psychostimulant medication, combining extended-release methylphenidate (ER-MPH) in the morning with immediate-release MPH (IR-MPH) in the afternoon, on cognitive task performance. Method: The sample comprised 24 children (19 boys and 5 girls) who met the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition Text Revision (DSM-IV-TR) criteria for an autism spectrum disorder (ASD) on the Autism Diagnostic Interview-R and the Autism Diagnostic Observation Schedule, and had significant symptoms of attention-deficit/hyperactivity disorder (ADHD). This sample consisted of elementary school-age, community-based children (mean chronological age = 8.8 years, SD = 1.7; mean intelligence quotient = 85; SD = 16.8). Effects of placebo and three dose levels of ER-MPH (containing 0.21, 0.35, and 0.48 mg/kg equivalent of IR-MPH) on cognitive task performance were compared using a within-subject, crossover, placebo-controlled design. Each of the four MPH dosing regimens (placebo, low-dose MPH, medium-dose MPH, and high-dose MPH) was administered for 1 week; the dosing order was counterbalanced across children. Results: MPH treatment was associated with significant performance gains on cognitive tasks tapping sustained attention, selective attention, and impulsivity/inhibition. Dose/response was generally linear in the dose range studied, with no evidence of deterioration in performance at higher MPH doses in the dose range studied. Conclusion: The results of this study suggest that MPH formulations are associated with significant improvements on cognitive task performance in children with ASD and ADHD.

Emotion Regulation via the Autonomic Nervous System in Children with Attention-Deficit/Hyperactivity Disorder (ADHD): Replication and Extension.

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent disorder characterized by symptoms of inattention, hyperactivity, and/or impulsivity, as well as executive dysfunction. Recent work underlines the importance in understanding the role of emotion reactivity and regulatory deficits in the context of the disorder. One study (i.e., Musser et al. 2011) utilized a positive and negative emotion induction and suppression task, as well as indexes of autonomic nervous system reactivity, to examine emotional functioning in youth with ADHD. This study revealed inflexible parasympathetic-based regulation across emotion conditions among youth with ADHD compared to typically developing youth. The present study sought to replicate and extend these findings to a clinically recruited, diverse sample, while also examining sympathetic functioning. Two hundred fifty-nine participants (160 youth with ADHD), aged 5 to 13, completed the task utilized in Musser et al. 2011, while indexes of parasympathetic (i.e., respiratory sinus arrhythmia [RSA]) and sympathetic (i.e., pre-ejection period [PEP] and electrodermal activity [EDA]) reactivity were obtained. ADHD was associated with significantly elevated parasympathetic (i.e., augmented RSA) and sympathetic (as indexed by EDA) reactivity. Overall, results replicate and extend Musser et al. 2011, revealing sympathetic-linked disruptions in emotion reactivity and parasympathetic-linked disruptions in emotion regulation among youth with ADHD. Future studies of behavioral therapies for ADHD should consider the efficacy of adding an emotion regulation skills training component.

Relational impairments, sluggish cognitive tempo, and severe inattention are associated with elevated self-rated depressive symptoms in adolescents with ADHD.

This study examines how ADHD-related symptoms and impairments interact to predict depression symptoms in young adolescents with ADHD. A sample of 342 adolescents (71% male, mean age = 13 years old) with DSM-IV-TR diagnosed ADHD completed baseline clinical assessments upon entry to a psychosocial treatment study for ADHD. Ratings of ADHD and sluggish cognitive tempo (SCT) symptoms, and social and academic impairment were obtained from parents, while ratings of depressive symptoms and conflict with parents were obtained from youth. Among adolescents with ADHD, elevated depressive symptoms were associated with higher SCT symptom severity, lower hyperactive/impulsive (HI) symptom severity, higher social impairments, higher conflict with parents, and lower academic problems. Interaction effects indicated that clinically significant depressive symptoms were most likely to occur when high levels of parent-youth conflict were present along with high inattentive (IN) symptoms, high SCT, and/or low HI. Among children and adolescents with ADHD, depression prevention efforts might target IN/SCT symptom management, as well as improving interpersonal relationships with parents and peers. Future work is needed to verify these findings longitudinally.

Response Inhibition, Response Execution, and Emotion Regulation among Children with Attention-Deficit/Hyperactivity Disorder.

Attention-deficit/hyperactivity disorder (ADHD) is associated with deficits in response inhibition, response execution, and emotion regulation. However, the nature of the associations among these deficits remains unclear. Thus, this study examines these associations using a multi-method design. One hundred sixty-six children (aged 5-13 years; 66.3% male; 75 with ADHD) completed two conditions (i.e., neutral and fear) of an emotional go/no-go task. Parasympathetic-based regulation was indexed via respiratory sinus arrhythmia (RSA), and sympathetic-based reactivity was indexed via cardiac pre-ejection period (PEP). Overall, children exhibited more difficulty with response execution (i.e., more omission errors, fewer correct go responses) and less difficulty with response inhibition (i.e., fewer commission errors, more correct no-go responses) during the fear condition than the neutral condition. Children with ADHD displayed more difficulty with response execution during the fear condition compared to typically developing youth. Additionally, children with ADHD displayed parasympathetic-based dysregulation (i.e., RSA increase from baseline) and reduced sympathetic-based reactivity (i.e., PEP lengthening) compared to typically developing youth across task conditions. In sum, children with ADHD demonstrate greater difficulty with response execution during emotionally salient contexts, as well as parasympathetic-based emotion dysregulation. Future work should examine these associations longitudinally with the aim of predicting impairment and treatment response in youth with ADHD.

Correction to: Variation in Parasympathetic Dysregulation Moderates Short-Term Memory Problems in Childhood Attention-Deficit/Hyperactivity Disorder.

The authors note two errors in this article. In the reference section, Musser et al. (2014) was mistakenly used whereas the following entry should have been used.

Parent Emotion Expression and Autonomic-Linked Emotion Dysregulation in Childhood ADHD.

Despite evidence that ADHD is associated with disruptions in emotion regulation, few studies have examined the biological correlates of emotion dysregulation among children with this disorder. Prior work has pointed to roles of the parasympathetic and sympathetic nervous system, as indexed via respiratory sinus arrhythmia (RSA) and cardiac pre-ejection period (PEP), respectively. Work in typically developing populations suggests that parenting behavior and parental emotion expression may shape the development of these systems. To date, a single study has examined the independent and interactive roles of autonomic nervous system functioning and parent emotion expression in youth with ADHD. This study seeks to extend that work. 86 children (42 with ADHD), aged 8-12 years, and a parent completed a parent-child interaction task, while electrocardiography and impedance cardiography data were recorded to derive RSA and PEP. Parent and child emotion word use (positive and negative valence) were coded from recordings of the task. Parents of youth with ADHD used fewer positive emotion words throughout the task. Additionally, throughout the task, children with ADHD engaged in excessive RSA withdrawal from baseline. Further, the association between RSA reactivity and ADHD diagnosis was moderated by parent positive emotion word use. Specifically, those with RSA augmentation and parents displaying high positive affect across the task conditions were least likely to have an ADHD diagnosis. If replicated and extended, these results support the use of interventions specifically designed to increase parental modeling of positive emotions, while simultaneously focusing on building emotion regulation skills in youth with ADHD.

Variation in Parasympathetic Dysregulation Moderates Short-term Memory Problems in Childhood Attention-Deficit/Hyperactivity Disorder.

Although attention deficit/hyperactivity disorder (ADHD) is associated with impairment in working memory and short-term memory, up to half of individual children with ADHD perform within a normative range. Heterogeneity in other ADHD-related mechanisms, which may compensate for or combine with cognitive weaknesses, is a likely explanation. One candidate is the robustness of parasympathetic regulation (as indexed by respiratory sinus arrhythmia; RSA). Theory and data suggest that a common neural network is likely tied to both heart-rate regulation and certain cognitive functions (including aspects of working and short-term memory). Cardiac-derived indices of parasympathetic reactivity were collected during short-term memory (STM) storage and rehearsal tasks from 243 children (116 ADHD, 127 controls). ADHD was associated with lower STM performance, replicating previous work. In addition, RSA reactivity moderated the association between STM and ADHD - both as a category and a dimension - independent of comorbidity. Specifically, conditional effects revealed that high levels of withdrawal interacted with weakened STM but high levels of augmentation moderated a positive association predicting ADHD. Thus, variations in parasympathetic reactivity may help explain neuropsychological heterogeneity in ADHD.