Thomas E. Brown

Executive Functions and Attention Deficit Hyperactivity Disorder: Implications of two conflicting views

While increasing numbers of articles and books refer to Attention Deficit Hyperactivity Disorder (ADHD) as a disorder of “executive function” of the mind, two conflicting views have emerged about how ADHD and executive function are related. In one view it is argued that some, but not all, who meet the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders diagnostic criteria for ADHD suffer from significant impairments of executive function. The alternative view holds that all individuals with ADHD suffer from significant impairment of executive function, and that ADHD essentially is a developmental impairment of executive function. These conflicting viewpoints rest upon divergent understandings of the nature of executive functions and how these functions should be assessed. Each leads to a very different conclusion about the essential nature of ADHD and its relationship to other learning and psychiatric disorders. This article describes and evaluates those two views and their implications.

Assessment and Management of Sleep Problems in Youths With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE To provide evidence- or consensus-based recommendations concerning the assessment and management of sleep problems in youths with attention-deficit/hyperactivity disorder (ADHD). METHOD PubMed, Ovid, EMBASE, and Web of Knowledge were searched through October 31, 2012. When no evidence was available, consensus of the authors was achieved. The evidence-level of the recommendations on the management of sleep disturbances was based on the Scottish Intercollegiate Guidelines Network (SIGN) system. RESULTS A total of 139 original articles on sleep and childhood ADHD were retrieved, including 22 on treatment of sleep disturbances. This review focuses on behaviorally based insomnia, circadian rhythm disorder, sleep-disordered breathing, restless legs syndrome/periodic limb movement disorder, and sleep disturbances due to comorbid psychiatric disorders or ADHD medications. Healthy sleep practices are recommended as the foundation of management strategies. Behavioral interventions should be considered as first-line treatment of insomnia, although further evidence from randomized controlled trials (RCTs) is needed to prove their efficacy in ADHD. Among pharmacological treatments, RCTs support the use of melatonin to reduce sleep-onset delay, whereas there is more limited evidence for other medications. CONCLUSION Growing empirical evidence is informing assessment/management strategies of sleep problems in youths with ADHD. However, further RCTs are warranted to support current recommendations.

Unrecognized attention-deficit/hyperactivity disorder in adults presenting with other psychiatric disorders.

Many adults with a diagnosed psychiatric disorder also have attention-deficit/hyperactivity disorder (ADHD). In many cases, comorbid ADHD is unrecognized and/or undertreated. Differential diagnosis of adult ADHD can be challenging because ADHD symptoms may overlap with other psychiatric disorders and patients may lack insight into their ADHD-related symptoms. Current ADHD diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision may prevent appropriate diagnosis of many patients with significant ADHD symptoms. Adults may not be able to provide a history of onset of symptoms during childhood, and it may be difficult to confirm that ADHD symptoms are not better accounted for by other comorbid psychiatric conditions. Comorbid ADHD is most prevalent among patients with mood, anxiety, substance use, and impulse-control disorders. ADHD can negatively affect outcomes of other comorbid psychiatric disorders, and ADHD symptoms may compromise compliance with treatment regimens. Furthermore, unrecognized ADHD symptoms may be mistaken for poor treatment response in these comorbid disorders. In these individuals, ADHD pharmacotherapy seems to be as effective in reducing core ADHD symptoms, as it is in patients who have no comorbidity. Limited evidence further suggests that ADHD therapy may help to improve symptoms of certain psychiatric comorbidities, such as depression. Therefore, management of ADHD may help to stabilize daily functioning and facilitate a fuller recovery.

Attention Deficit Disorders and Sleep/Arousal Disturbance

Abstract: Many children, adolescents, and adults with Attention Deficit Disorders report chronic difficulties with falling asleep, awakening and/or maintaining adequate daytime alertness. These problems may be due to a variety of factors, including environment, lifestyle, and psychiatric comorbidities. Impairments in sleep/arousal may also be related more directly to the underlying pathophysiology of ADD. This chapter describes clinical manifestations of sleep/arousal problems often associated with ADD and reviews behavioral and medication options for treatment.

Validation of the Adult ADHD Investigator Symptom Rating Scale (AISRS)

Objective: Validation of the Adult ADHD Investigator Symptom Rating Scale (AISRS) that measures aspects of ADHD in adults. Method: Psychometric properties of the AISRS total and AISRS subscales are analyzed and compared to the Conners’ Adult Attention-Deficit/Hyperactivity Disorder Rating Scale-Investigator Rated: Screening Version (CAARS-Inv:SV) and the Clinical Global Impression-ADHD-Severity Scale using data from a placebo-controlled 6-month clinical trial of once-daily atomoxetine. Results: The AISRS has high internal consistency, good convergent, and discriminant validities; modest divergent validity; and small ceiling and floor effects (≤1%). It correlates highly with the CAARS-Inv:SV. Factor analysis confirms 2 AISRS subscales, hyperactivity-impulsive scale and inattention. The AISRS total and AISRS subscales perform stably. All scales demonstrate responsiveness to change with medication. Conclusion: The AISRS and its subscales are robust, valid efficacy measures of ADHD symptoms in adult patients. Its anchored items and semistructured interview are advancements over existing scales. (J. of Att. Dis. 2010; 14(1) 57-68)

Executive Function Impairments in High IQ Adults With ADHD

Objectives: To demonstrate that high IQ adults diagnosed with ADHD suffer from executive function (EF) impairments that: a) can be identified with a combination of standardized measures and self-report data; and b) occur more commonly in this group than in the general population. Method: 157 ADHD adults with IQ ≥ 120 were assessed with 8 normed measures of EF— 3 index scores from standardized tests of memory and cognitive abilities, and 5 subscales of a normed self-report measure of EF impairments in daily life. Results: 73% of subjects were significantly impaired on ≥ 5 of these 8 EF markers. On all 8 measures, incidence of these impairments was significantly greater than in the general population. Conclusion: High IQ adults with ADHD tend to suffer EF impairments that can be assessed with these measures; incidence of such impairments in this group is significantly higher than in the general population. (J. of Att. Dis. 2009; 13(2) 161-167)

Assessment of short-term verbal memory impairments in adolescents and adults with ADHD:

The purpose of this study was to determine whether a brief measure of verbal memory can assess short-term verbal memory impairments relative to verbal abilities in adolescents and adults with Attention-Deficit/Hyperactivity Disorder (ADHD) and to ascertain whether significant differences between short-term verbal memory and verbal abilities are more common among persons with ADHD than in the general population. One hundred seventy-six adolescents and adults diagnosed with ADHD (DSM-IV criteria) were assessed with a measure of short-term verbal memory. The short-term verbal memory score of each subject was compared with the verbal abilities on two measures. Percentages of ADHD subjects with “significant discrepancy” between verbal IQ and short-term verbal memory were compared with the standardization sample for the verbal memory measure. A majority of adolescents and adults diagnosed with ADHD demonstrated significant discrepancy between performance on the short-term verbal memory measure and verbal IQ. The percentage of ADHD subjects with a significant discrepancy between these two measures greatly exceeded the percentage of persons in the general population showing such a discrepancy. This brief measure of short-term verbal memory may be a useful measure to include in a comprehensive assessment for ADHD symptoms in adolescents and adults. Replication in other groups of ADHD patients is needed to test the generalizability of the findings.

Improvements in Executive Function Correlate with Enhanced Performance and Functioning and Health-Related Quality of Life: Evidence from 2 Large, Double-Blind, Randomized, Placebo-Controlled Trials in ADHD

Abstract Objective: To assess whether improvement in executive function correlates with perceived improvement in health-related quality of life (HRQOL) in adults with attention-deficit/hyperactivity disorder (ADHD) who are treated with stimulant medication. Methods: We collected data on executive function and HRQOL using the Brown Attention-Deficit Disorder Scale (BADDS) and the ADHD Impact Module–Adult (AIM-A) during 2 large, randomized, double-blind, placebo-controlled trials evaluating the use of the triple-bead mixed amphetamine salt (MAS) SPD465 as stimulant pharmacotherapy for ADHD. BADDS and AIM-A data were collected at baseline and at study endpoint, and changes from baseline were assessed. Correlation coefficients for BADDS and AIM-A were calculated at baseline and endpoint for each study. Results: The change from baseline in BADDS total score was –14.8 ± 24.49 in Study 1 (dose optimization strategy) and –26.1 ± 28.54 in Study 2 (forced-dose titration strategy), demonstrating substantial reported improvement in executive function. In both studies, improvement was reported for all 5 BADDS clusters at study endpoint versus baseline. While improvement was reported for all 6 AIM-A scales at study endpoint versus baseline, the most substantial change from baseline in AIM-A scores over the course of the studies was in Performance and Function (Study 1, +15.2 ± 25.68; Study 2, +26.3 ± 28.17). There was significant correlation of the BADDS total score with the AIM-A Performance and Function scale (Study 1, –0.6723; Study 2, –0.6982), and strong correlations were observed between each of the 5 individual clusters of BADDS and AIM-A performance and function in both studies. Conclusions: Reported improvement in executive function correlates with reported improvement in HRQOL as assessed in 2 independent clinical trials in which participants received either placebo or triple-bead MAS for the treatment of ADHD. In particular, there were strong correlations between all 5 individual clusters of BADDS and the AIM-A Performance and Function scale. [Trial registration: ClinicalTrials.gov, Identifier: NCT00150579 and NCT00152022]

Effect of Atomoxetine on Executive Function Impairments in Adults with ADHD.

Objective: To assess the effect of atomoxetine on ADHD-related executive functions over a 6-month period using the Brown Attention-Deficit Disorder Scale (BADDS) for Adults, a normed, 40-item, self-report scale in a randomized, double-blind, placebo-controlled clinical trial. Method: In a randomized, double-blind clinical trial, adults with ADHD received either atomoxetine 25 to 100 mg/day or placebo for 6 months. Patients completed the BADDS to report their current daily functioning in 5 clusters of ADHD-related impairments of executive functioning: (1) Organizing and Activating to Work; (2) Focusing for Tasks; (3) Regulating Alertness and Effort; (4) Modulating Emotions; and (5) Utilizing Working Memory. Results: Mean scores were significantly more improved in the atomoxetine group compared to the placebo group: total score, -27.0 versus -19.0 (p < .001); all 5 cluster scores, p < .01. Conclusions: Once-daily atomoxetine can improve executive function impairments in adults with ADHD as assessed by the BADDS. (J. of Att. Dis. 2011; 15(2) 130-138)

Open-Label Administration of Lisdexamfetamine Dimesylate Improves Executive Function Impairments and Symptoms of Attention-Deficit/Hyperactivity Disorder in Adults

Abstract Introduction/Objective: Executive function (EF) impairment in attention-deficit/hyperactivity disorder (ADHD) may account for behavioral symptoms such as poor concentration, impaired working memory, problems in shifting among tasks, and prioritizing and planning complex sets of tasks or completing long-term projects at work or school. Poor self-regulation and control of emotional behaviors frequently are seen in patients with ADHD. This study assessed EF behaviors in adults with ADHD at baseline and after 4 weeks of treatment with lisdexamfetamine dimesylate (LDX). Methods: Executive function behavior was assessed using the Brown Attention-Deficit Disorder Scale (BADDS) during the 4-week open-label dose-optimization phase prior to a 2-period, randomized, double-blind, placebo-controlled crossover study of LDX (30–70 mg/day). The ADHD Rating Scale IV (ADHD-RS-IV) with adult prompts assessed ADHD symptoms. Change in EF behavioral symptoms was evaluated based on week 4 BADDS total and cluster scores; analyses of shifts from baseline among subjects with BADDS scores < 50, 50 to 59, 60 to 69, and ≥ 70; and scores less than or greater than baseline 90% confidence range (eg, reliably improved or worsened, respectively). Treatment-emergent adverse events (TEAEs) were described. Results: At week 4, BADDS total and cluster scores were reduced (ie, improved; all P < 0.0001 vs baseline [n = 127]). The ADHD-RS-IV with adult prompts scores also improved (all P < 0.0001 vs baseline). At week 4, 62.7% of subjects had a BADDS total score of < 50, and 78.9% were reliably improved; 1.4% were reliably worsened. Common TEAEs (≥ 5%) during the dose-optimization phase were decreased appetite (36.6%), dry mouth (30.3%), headache (19.7%), insomnia (18.3%), upper respiratory tract infection (9.9%), irritability (8.5%), nausea (7.7%), anxiety (5.6%), and feeling jittery (5.6%). Conclusion: Clinically optimized doses of LDX (30–70 mg/day) significantly improved EF behaviors in adults with ADHD. Treatment-emergent adverse events with LDX were consistent with those observed with long-term stimulant use.