Attention Deficit Hyperactivity Disorder (ADHD): Overview and Theories on its Causes
Lahey & Carlson (1991) reviewed the research literature and concluded that was then called formerly called ADD was found in two independent dimensions:
1. one consisting of motor hyperactivity and impulsive behavior
2. the other consisting of inattention disorganization, and difficulty completing tasks
They concluded "it no longer seems doubtful that ADD/WO "exists," and that ADD without hyperactivity differs from ADD with hyperactivity in clinically important ways."
Brown & Gammon (1992, 1993) at Yale suggest that more is involved in ADHD without hyperactivity than just inattention. Such is not just a mild case of ADHD, but can be a debilitating disorder in which even bright and talented people are unable to activate themselves and sustain their efforts for productive work. What is called apathy or lack of motivation is a chronic problem with activation, which may be central to understanding this type of ADHD.
Many of those with non-hyperactive ADHD report chronic problems with "getting cranked up" to do tasks, even tasks they recognize as urgent and important for their own welfare. Often this activation problem in ADHD extends to sustaining energy for tasks. Many patients report great difficulty keeping up their energy to read or write or do a task. They speak of feeling drowsy even after a good night's sleep. Some almost meet the diagnostic category for narcolepsy, reporting problems with dozing at long stoplights and difficulty fighting off drowsiness while studying, listening to lectures, or attending meetings. There appears to be chronic difficulty not only in activating to work, but in sustaining energy for tasks.
Chronic problems in activating and sustaining arousal make life difficult for high-IQ people, who are seen by themselves, parents, teachers, and employers as extremely bright, with great promise for successful achievement. The symptoms of chronic inattention, lethargy, failure to follow through, brings oscillating achievement, poor grades and frequent reminders that "you could do much better if only you'd be more consistent." The wide gap between their potential and actual achievement can make these patients vulnerable to demoralization and resignation to failure.