ADHD & How Anyone Can Improve Their Focus

KEYPOINTS

• 01

  ADHD is strongly genetic and unrelated to intelligence

  ADD appears in the medical literature as early as 1904 and was renamed ADHD in the mid-to-late 1980s. If an identical twin has ADHD, the other's chance is up to 75%, compared with about 50–60% for fraternal twins and 10–25% when a parent has it. Huberman stresses that ADHD appears across every level of IQ, emotional intelligence and other kinds of intelligence. A family history raises risk but does not determine the outcome, and symptoms can be overcome.

• 02

  The core problems are attention, impulse control, time and working memory

  People with ADHD often hyper-focus on things they enjoy, which shows the capacity for focus exists but is hard to direct. They also struggle with time perception, run late, organize in 'piles' and have weak working memory. Huberman links hyper-focus on preferred activities to dopamine.

• 03

  In ADHD, the brain's resting and task networks fire together instead of opposing each other

  The default mode network, which Huberman describes as including the dorsolateral prefrontal cortex, posterior cingulate and lateral parietal lobe, is normally synchronized internally. Task networks, centered on the medial prefrontal cortex, suppress impulses. Normally the two are anti-correlated, like a seesaw. In ADHD, after poor sleep, or in subclinical cases, they are abnormally correlated, like a band where every instrument plays melody. With successful treatment or when people outgrow ADHD, they return to anti-correlation.

• 04

  Under the low-dopamine hypothesis, neurons fire when they should stay quiet

  When dopamine is too low in attention circuits, neurons fire out of turn, like musicians ignoring the rests. Since the 1940s–60s, people with ADHD have tended to self-medicate with lots of coffee, half a pack of cigarettes a day, cocaine or amphetamine, all of which raise dopamine. Young children with ADHD often show a strong preference for sugary foods, which also raise dopamine.

• 05

  Stimulant drugs may teach the brain to focus

  Ritalin (methylphenidate) and Adderall (an amphetamine) raise dopamine and norepinephrine. Huberman's framing is that they let children experience sustained focus so the circuits for focus can be trained, rather than acting as a permanent crutch. Modafinil and armodafinil are weaker dopamine reuptake inhibitors that also act on the orexin (hypocretin) system, which is disrupted in narcolepsy, so they are a milder alternative.

• 06

  Attentional blinks: finding one target makes you miss the next

  Huberman credits Daniel Goleman and Richard Davidson's account. In a Where's Waldo-style search, or when spotting the letters R and Z in a fast stream of numbers, people who detect the first target often miss a second one shortly after, because attention briefly shuts off during a small neurochemical 'celebration.' Children and adults with ADHD have many more of these blinks.

• 07

  Physical eye blinks reset your sense of time and are controlled by dopamine

  A Current Biology paper, 'Time dilates after spontaneous blinking,' shows that blinks reset time perception, like the clapper between takes on a film set. Higher dopamine makes people overestimate how long something lasted because they sample time more finely, while low dopamine leads to underestimation, which fits the habitual lateness seen in ADHD. Chronic cannabis users blink less, and the more years of use, the lower their blink rate.

• 08

  Elimination diets and sugar: strong results with caveats

  A Lancet randomized crossover trial of 100 children (50 per group at any time) used an oligoantigenic diet that removed foods each child had mild antibody reactions to. It reported large improvements in focus, impulsivity and fidgeting with p-values below 0.00001, but later reanalyses criticized the design. A pediatric neurologist friend of Huberman's says cutting simple sugars has a dramatic positive effect in many of her patients, which is a well-informed anecdote, not a trial.