Monitoring Adults With ADHD: A Focus on Executive and Behavioral Function
Lenard A. Adler, MD
Departments of Psychiatry and Child and Adolescent Psychiatry, New York University School of Medicine and Psychiatry Service, New York VA Harbor Healthcare System, New York
Current theory proposes that the symptoms of adult ADHD may originate from deficits in neuropsychological functioning. In this model, deficits in the executive function domain of inhibition correlate with ADHD symptoms such as distractibility, impulsivity, and being unable to interrupt ongoing pleasurable activities. These symptoms contribute to deficits in the executive function domain of metacognition, which comprises nonverbal working memory, verbal working memory, emotional self-regulation, and planning and problem-solving.1 For more information on the presentation of ADHD and executive function, see “Differential Diagnosis of Adults With ADHD: The Role of Executive Function and Self-Regulation” by Russell A. Barkley, PhD.
Whether deficits in executive function are a part of the core ADHD symptomatology or are instead concurrent symptoms is yet to be decided. Biederman and colleagues2 examined the association between psychometrically defined deficits in executive function and functional outcomes in adults with ADHD. The authors compared adults with ADHD with controls and concluded that adults with ADHD were approximately twice as likely to have deficits in executive function (31% vs 16%, P = .001). Additionally, although ADHD alone caused some impairment, patients with both ADHD and deficits in executive function had more impairment, particularly in academic performance (AV 1).2 However, the results demonstrated that many adults with ADHD will not have deficits in executive function according to these neuropsychological measures.
Nevertheless, for those adults with ADHD and deficits in executive function, neuropsychological testing has shown fairly consistent impairments in attention, behavioral inhibition, and memory.3 In addition, a number of self-rating scales have been developed to assess executive function as it relates to daily life activities in adults with ADHD. These scales are hypothesized to assess a different hierarchical level of executive function4 and are useful for evaluating the course of ADHD in individuals.
Monitoring Executive Function in ADHD
Neuropsychological tests. A review5 found that the neuropsychological tests that most consistently differentiated persons with ADHD from controls were the CPT, the Stroop Color and Word Test,6 the Trail Making Test,7 the COWAT,8 and the WAIS-III.9
In the CPT, of which there are several variations, an individual is asked to acknowledge when a particular letter or symbol, such as X, is presented, or, in a variation, acknowledge the letter or symbol only when preceded by another set letter, such as A. The CPT measures variables such as reaction time, errors of omission (when the presentation is missed), and errors of commission (when the presentation is acknowledged but was not presented), which reflect an individual’s variability of attention and vigilance.
The Stroop Color and Word Test presents the following lists: (1) names of colors, (2) names of colors printed in matching ink, and (3) names of colors printed in other colors of ink. The Stroop is an interference task that measures response inhibition (ie, ignoring the ink color when answering) and working memory (ie, keeping in mind that there is a difference between what the word says and the color of ink it is printed in when making a response).
The Trail Making Test has 2 versions: Trails A and Trails B. Trails A is a combination of visual search and perceptual motor speed. Trails B adds shifting sets (a measure of executive function) and may have a slightly greater effect size in differentiating individuals with ADHD than Trails A.
The COWAT measures verbal fluency by tapping into phonological associations (eg, naming words that begin with “b”) and category fluency (eg, naming all the animals you can see). The test can measure processing speed, persistence, and the rapidity of an individual’s access to their lexicon.
The WAIS-III measures intelligence through perceptual motor speed via a digit symbol coding test. Full-scale IQ and gaps in verbal and performance subscales are useful when assessing individuals for ADHD, and the WAIS-III indices also include working memory and processing speed, which are most likely to be impaired in ADHD.
Rating scales of executive function. Rating scales can quickly gather data (ie, the presence of ADHD symptoms and their frequency) and also measure response to treatment. Three common rating scales are the Current Symptoms Scale–Self-Report Form,10 the BADDS,11 and the BRIEF-A.12
The Current Symptoms Scale–Self-Report Form has 18 items correlated with the criteria for ADHD from the DSM-IV.13 Patients rate their symptom frequency in the last 6 months. Patients then answer a question regarding age at onset and rate how often their symptoms interfere with their ability to function in daily activities (eg, work, driving, financial management). At the end of the rating scale are 8 items addressing ODD, a frequent comorbidity of ADHD.
The BADDS is a 40-item, frequency-based self-report scale of symptom descriptors. The scale specifically assesses 5 dimensions of symptoms, which include organizing work, sustaining attention and concentration, sustaining alertness and effort, managing emotions, and using working memory.
The BRIEF-A is a self-report, frequency-rated scale that contains 75 items. An overall score, or Global Executive Composite, is derived from 2 index scores: the Behavioral Regulation Index and the Metacognitive Index. The Behavioral Regulation Index is comprised of 4 subscales (Inhibit, Shift, Emotional Control, and Self-Monitor), and the Metacognitive Index has 5 subscales (Initiate, Working Memory, Plan/Organize, Task Monitor, and Organization of Materials).
Improving Executive Function
Established and effective treatments are available for adults with ADHD. Treatments that have been studied in relation to improving executive function in adults with ADHD include psychosocial interventions and nonstimulant and stimulant medications.
Nonpharmacologic interventions. Safren et al14 studied CBT (which included psychoeducation, skills-learning, and cognitive restructuring) in 31 adults with ADHD who had partially responded to medication. The researchers compared ongoing medication treatment alone versus the combination of medication and CBT and examined changes in ADHD symptoms rather than executive functions specifically. The combination group reported less depression and anxiety and lower ADHD scores, and patients receiving adjunctive CBT were significantly more likely to be responders than those receiving medication alone (56% versus 13%, P < .02).
Stevenson and colleagues15 tested a cognitive remediation program in 43 adults with ADHD. Test subjects were randomly assigned to an intensive psychosocial intervention that targeted common ADHD symptoms or to a waiting-list control group. For participants in the intervention group, the authors noted reduced symptomatology along with improvements in organizational skills and self-esteem and reduced levels of anger, traits that can be directly correlated with executive function. In a recent study, Solanto and colleagues16 compared adults with ADHD receiving metacognitive therapy to build skills in planning, organization, and time management with a control group receiving supportive therapy. Those receiving metacognitive therapy experienced significantly greater improvements in ADHD symptom severity than those receiving supportive therapy (P < .05).
Pharmacologic treatment. Biederman et al17 compared subjects with ADHD being treated with stimulants, subjects with ADHD not being treated with stimulants, and control subjects without ADHD to evaluate the effect of stimulants on executive function. Individuals with ADHD treated with stimulants showed significantly higher scores on neuropsychological measures of attention (P = .04) and verbal learning (P = .03) compared with those who did not take stimulant medications (AV 2).
Atomoxetine, a nonstimulant medication, was assessed in a 6-month, randomized, placebo-controlled trial by Brown and colleagues.18 Patients in the study completed the BADDS self-report scale; mean scores in all 5 areas of executive function measured by the scale were significantly more improved for those taking medication than for those taking placebo (P < .001). For more information on treatments for ADHD, see “Risks and Benefits of Available Treatments for Adult ADHD” by Jeffrey H. Newcorn, MD.
For Clinical Use
- Be aware that deficits in executive function are more common in adults with ADHD than in adults without ADHD, and some deficits will not show up on neuropsychological tests
- Use self-rating scales to assess the presence of ADHD symptoms and to measure response to treatment
- Use treatments such as stimulant or nonstimulant medications and psychosocial interventions to improve executive function in your patients with ADHD
ADHD = attention-deficit/hyperactivity disorder, BADDS = Brown Attention Deficit Disorder Scale, BRIEF-A = Behavior Rating Inventory of Executive Function-Adult Version, CBT = cognitive-behavioral therapy, COWAT = Controlled Oral Word Association Test, CPT = continuous performance test, EFD = executive function deficits, ODD = oppositional defiant disorder, WAIS = Wechsler Adult Intelligence Scale
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- Barkley RA. Attention-Deficit Hyperactivity Disorder: Handbook for Diagnosis and Treatment. 2nd ed. New York, NY: Guilford Press; 1998.
- Biederman J, Petty C, Fried R, et al. Impact of psychometrically defined deficits of executive functioning in adults with attention deficit hyperactivity disorder. Am J Psychiatry. 2006;163(10):1730–1738.
- Hervey AS, Epstein JN, Curry JF. Neuropsychology of adults with attention-deficit/hyperactivity disorder: a meta-analytic review. Neuropsychology. 2004;18(3):485–503.
- Barkley RA, Murphy KR. Impairment in occupational functioning and adult ADHD: the predictive utility of executive function (EF) ratings versus EF tests [published online ahead of print March 2, 2010]. Arch Clin Neuropsychol. doi:10.1093/arclin/acq014.
- Seidman LJ, Doyle A, Fried R, et al. Neuropsychological function in adults with attention-deficit/hyperactivity disorder. Psychiatr Clin North Am. 2004;27(2):261–282.
- Golden CJ. Stroop Color and Word Test: A Manual for Clinical and Experimental Use. Chicago, IL: Stoelting Co; 1978.
- Reitan RM. Manual for Administration of Neuropsychological Test Batteries for Adults and Children. Tucson, AZ: Reitan Neuropsychology Laboratories; 1979.
- Benton AL, Hamsher K, Sivan AB. Multilingual Aphasia Examination. 3rd ed. Iowa City, IA: AJA Associates; 1983.
- Wechsler D. Wechsler Adult Intelligence Scale, III. San Antonio, TX: The Psychological Corporation; 1997.
- Barkley RA, Murphy KR. Attention-Deficit Hyperactivity Disorder: A Clinical Workbook, 2nd ed. New York, NY: Guilford Press; 1998.
- Brown TE. Brown Attention-Deficit Disorder Scales. San Antonio, TX: The Psychological Corporation; 1996.
- Roth RM, Isquith PK, Gioia GA. Behavioral Rating Inventory of Executive Function-Adult Version. Lutz, FL: Psychological Assessment Resources, Inc; 2005.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Washington, DC: American Psychiatric Association; 1994.
- Safren SA, Otto MW, Sprich S, et al. Cognitive-behavioral therapy for ADHD in medication-treated adults with continued symptoms. Behav Res Ther. 2005;43(7):831–842.
- Stevenson CS, Whitmont S, Bornholt L, et al. A cognitive remediation programme for adults with attention deficit hyperactivity disorder. Aust N Z J Psychiatry. 2002;36(5):610–616.
- Solanto MV, Marks DJ, Wasserstein J, et al. Efficacy of meta-cognitive therapy for adult ADHD [published online ahead of print March 15, 2010]. Am J Psychiatry. doi:10.1176/appi.ajp.2009.09081123.
- Biederman J, Seidman LJ, Petty CR, et al. Effects of stimulant medication on neuropsychological functioning in young adults with attention-deficit/hyperactivity disorder. J Clin Psychiatry. 2008;69(7):1150–1156.
- Brown TE, Holdnack J, Saylor K, et al. Effect of atomoxetine on executive function impairments in adults with ADHD [published online ahead of print December 21, 2009]. J Atten Disord. doi:10.1177/1087054709356165.