INTELLIGENT BUT INATTENTIVE
Yet another obstacle to diagnosis is that many individuals—particularly those with high intelligence—develop coping strategies that mask ADHD impairments; they may perform adequately in school as children but meet with difficulties during college and adulthood. Thomas E. Brown, PhD, assistant clinical professor of psychiatry at Yale University School of Medicine, noted that some adults seek evaluation and treatment for ADHD despite apparent career success—even completing law or medical degrees—because they feel they are not reaching their potential in their jobs and social relationships. These intelligent individuals, noted Dr. Brown, not only provide an opportunity to assess ways in which ADHD impairments interfere with cognitive functions but may shed light on the neuropsychologic nature of ADHD.
Dr. Brown and Yale colleague Donald Quinlan, PhD, collected data on 103 adults with ADHD (ages 18 to 63) who scored 120 or above on the Wechsler Adult Intelligence Scale-Revised, placing them in the top 9% of the population in terms of intelligence. Most of the patients were male (72%) and had predominantly inattentive or combined-type ADHD. Nearly all were high school graduates, while 56% had a bachelor's degree and 22% had a doctoral degree in medicine, law, or other fields. Yet 42% had dropped out of postsecondary education at least once; some had returned and dropped out multiple times because of difficulty meeting academic requirements. A similar proportion of subjects (41%) were significantly underemployed at evaluation, often in unskilled jobs.
"Despite superior IQ, many subjects showed impairments on IQ subtests sensitive to attention and concentration problems relative to their high scores on other verbal subtests," Dr. Brown reported. For example, on a test of verbal memory (the Wechsler Memory Scale-Revised Logical Memory I), 77% of subjects scored below the 60th percentile and 23% scored below the 25th percentile.