Not much more was known about ADHD.
In the 1970s, the number of ADHD diagnoses rose when ADHD doctors recognized that hyperactive children also had significant problems paying attention to tasks or listening to their teachers.
This discovery paved the way for changing the name of the disorder in 1980 from "hyperkinetic disorder" to "attention deficit disorder" and to recognizing that some children suffer from chronic inattention problems without significant hyperactivity.
That change, from an exclusive focus on hyperactivity and impulsive behavior to a focus on inattention as the principal problem of the disorder, was the first major paradigm shift in understanding this syndrome.
In recent years, there's been another major shift in our understanding of ADHD. Increasingly, researchers are recognizing that ADHD symptoms overlap with impairments in what neuropsychologists call executive functions. The term refers not to the activities of corporate executives, but to the brain's cognitive management functions. The term is used to refer to brain circuits that prioritize, integrate, and regulate other cognitive functions.
Everyone I've ever evaluated for ADD has some domains of activity where they can pay attention without difficulty. Some are artistic, and they sketch intently. Others are childhood engineers, constructing marvels with Lego blocks and, in later years, repairing engines or designing computer networks. Others are musicians who push themselves for hours at a time to learn a new song or to compose a new piece of music.
How can someone who is good at paying attention to some activities be unable to pay attention to other tasks that they know are important? When I pose this question to patients with ADD, most say something like: "It's easy! If it's something I'm really interested in, I can pay attention. If it's not interesting to me, I can't, regardless of how much I might want to."
Most non-ADDers respond to this answer with skepticism. "That's true for anyone," they say. "Anybody's going to pay better attention to something they're interested in than to something they're not." But when faced with something boring that they know they have to do, non-ADDers can make themselves focus on the task at hand. People with ADD lack this ability unless they know that the consequences of not paying attention will be immediate and severe.
Metaphors for executive functions
Imagine a symphony orchestra in which each musician plays his or her instrument very well. If there is no conductor to organize the orchestra, to signal the introduction of the woodwinds or the fading out of the strings, or to convey an overall interpretation of the music to all players, the orchestra will not produce good music.
Symptoms of ADD can be compared to impairments, not in the musicians but in the conductor. Typically, people with ADD are able to pay attention, to start and stop their actions, to keep up their alertness and effort, and to use their short-term memory effectively when engaged in certain favorite activities. This indicates that these people are not totally unable to exercise attention, alertness, or effort. They can play their instruments very well - but only sometimes. The problem lies in their chronic inability to activate and manage these functions in the right way at the right time.
One way to consider this broader view of attention as executive functions is to observe situations where tasks are not dealt with effectively. Martha Bridge Denckla, M.D., professor of neurology, pediatrics, and psychiatry at Johns Hopkins University School of Medicine, in Baltimore, has written about intelligent patients with no specific learning disabilities who have chronic difficulties in dealing effectively with tasks. In Attention Memory and Executive Function, she compares these people to a disorganized cook trying to get a meal on the table.