多动症，也许根本不是“注意力”的问题

Psychiatrist Awais Aftab finds that more and more people come in with the same bundle of troubles.

They find it hard to concentrate, often forget things, live disorganized lives, can't sit still and act on impulse.

From spreadsheets and memos to laundry and cooking, from showing up to appointments to meeting deadlines, they can't cope with the necessities of daily life.

More and more patients see their problems as problems of "attention," and more and more people think they have attention deficit hyperactivity disorder, what we usually call ADHD.

The rise in ADHD diagnoses and in the use of stimulant drugs has set off a big debate among the public and among psychiatrists.

Has medicine finally recognized a long-overlooked disorder, or has the diagnosis become too broad, turning ordinary difficulties into illness?

Aftab believes that behind this debate lies a more basic scientific question: what is ADHD, really?

Despite the words "attention deficit" in its name, a lack of attention may not be the right way to understand ADHD at all.

Last year, the journal Cell published an important study of how stimulant drugs affect the networks in children's brains.

The researchers found the drugs affect brain networks related to salience, reward and arousal.

But whether or not the children had been diagnosed with ADHD, no clear change was found in the brain's attention networks.

Aftab says this shows that the popular idea of ADHD, a lack of attention that medicine makes up for, may not be entirely accurate.

Aftab explains that "attention" means different things in the clinic and in the lab.

To neuroscientists, attention means the brain picking out the useful part of lots of information and amplifying it.

But what people mean by ADHD's "attention problems," like drifting off halfway through a task, losing the thread of a conversation or forgetting instructions, are really failures of "sustained engagement."

Attention is like a spotlight aimed at what matters right now; sustained engagement is keeping that light pointed at the same spot.

Whether the light stays there may depend more on whether the brain thinks the task is worth doing.

Once you see this, the study's results make sense.

Stimulant drugs look like they improve attention, but what they really do is make mundane things like math homework and laundry seem more important and more worthwhile to the brain.

That also explains why these drugs calm hyperactive children.

If a child can't sit still because the task at hand isn't rewarding enough, then once the drug makes the task seem "worth it," the child naturally no longer needs to look for stimulation elsewhere.

In fact, since the 1990s, scientists have questioned whether attention is really the core of ADHD.

In 1992, the developmental psychologist Edmund Sonuga-Barke and colleagues had hyperactive children choose again and again between a small reward right away and a larger reward after waiting.

They found the children chose the small reward only when doing so ended the experiment sooner.

In other words, these children's real problem may be an intense dislike of waiting.

Another clinical neuropsychologist, Russell Barkley, argues that people with ADHD live in a shrunken present, where future consequences carry little weight; Barkley calls this "time blindness."

Aftab says the wrong name causes confusion: people who are always late, easily bored, emotionally volatile, or can't get going without a deadline may never be diagnosed, because their problems don't sound like "attention."

On the other hand, modern work demands juggling many tasks and putting up with lots of tedious work, and together with phones and social media, that makes life harder for people with ADHD.

Still, the consensus in psychiatry is that ADHD is a genuine problem, with effective treatments.

Observational studies show that treating ADHD with medication is associated with reductions in deaths, self-harm, traffic accidents, crime and substance misuse.

Aftab says the most important thing in understanding ADHD is not to be confused by its name, because the name is a poor guide to how the human brain works.

Do you think the name of an illness can affect how we see it?