A new paper proposes that research in ADHD should shift focus from attention to energy. As a chronically-fatigued creature of the night with ADHD and a severe caffeine addiction, my interest was piqued!
The author, Mohammed Dawood Rahimi, is a cognitive neuroscience researcher based in Berlin, and I had the pleasure of speaking to him about his work last week. Dr. Rahimi was initially inspired by his clinical work with patients who had migraines, ADHD, and sensory processing disorder.
Many of these patients were also night owls, and when he asked why they preferred to be nocturnal, they told him that it was quieter and less intense than being awake in the daytime. This got him thinking about energy consumption, because it takes brain energy to filter out stimuli, and the brain is a particularly energy-hungry organ.
He found a 1990 paper by AJ Zametkin and colleagues that measured glucose metabolism in the brains of adults with a history of hyperactivity and those without.1 (The hyperactive adults also had never taken stimulants, which rules out a huge confounding factor in a lot of ADHD research.)
Glucose is brain fuel, and through PET scans, Zametkin et al found that the hyperactive subjects were metabolizing 8% less glucose on average than the controls, and regions of the brain connected to motor control and attention were particularly affected.
In an attention task, though, the groups didn’t differ, which is interesting, and actually doesn’t counter Rahimi’s hypothesis that energy in ADHD is ‘conditionally available.’ The authors note that it was a pretty easy task, and the subjects may have done worse if it was more taxing.
“Variability in executive performance is among the most robust empirical findings in ADHD research, appearing across ages, task domains, and environmental contexts,” Rahimi writes, and as a framework, EDHD could explain this.2
“Imagine a smartphone running a very demanding application for a long time. The phone may still work, [but] the resources become constrained or limited,” he explained to me. “Then the system starts changing how it allocates the apps. Some processes are maintained, but others are reduced, so performance of this smartphone can become less stable.”
In contrast to popular framings of ADHD as a deficit of executive function, the EDHD model looks at ‘when executive function is reliably available rather than whether it exists.’ Two factors are at play here: how the body consumes energy, and how it recovers during sleep.
The first factor has to do with mitochondria, the parts in our cells that turn food into adenosine triphosphate, or ATP, which the body uses for energy. There is emerging evidence for mitochondria dysfunction in ADHD,3 and an association between ADHD and oxidative stress, which can damage cells in the body.4
There’s also a significant overlap between ADHD and chronic fatigue: children with ADHD are twice as likely to experience chronic disabling fatigue by age 18, according to a 2024 study, and 62% of ADHDers in a 2017 study met criteria for fatigue.
ADHD’s overlap with chronically fatiguing conditions like hypermobility, POTS, ME/CFS, fibromyalgia, and Mast Cell Activation Syndrome is so significant that Dr. James Kustow in the UK has taken to calling it a ‘somatic supersyndrome’.
People with ADHD also have a lot of trouble sleeping — one 2025 paper estimates that 80% of ADHDers experience sleep disturbances, and goes so far as to call it a circadian rhythm disorder.
So how does chronic fatigue square with hyperactivity and impulsivity? In Rahimi’s model, these behaviors are reframed as compensatory strategies — they may be a way that the brain is attempting to wake up in the face of waning energy. There’s a catch, though — Rahimi calls them ‘energetically expensive stabilizers.’ They help in the moment, but increase fatigue in the long run.
“The brain wants the person not to sit down — to walk, to do something, in order to have more energy or flow in the brain,” Rahimi told me. “But that behavior also consumes energy. It is not a solution.”
He gives an example of this in the paper, with a fictional case study of an adult with ADHD:
“Alex experiences bursts of productivity followed by rapid cognitive collapse. He relies on pacing behaviors, movement breaks, and environmental modulation (e.g., music, task cycling) to sustain output. Rather than reflecting poor discipline or motivational failure, EDHD interprets these behaviors as energy-management responses under prolonged executive load.”
As a serial task-switcher with constant music in my headphones, I felt extremely called out by this. I write 500 words, I get up and work on a sewing project, I do the dishes, I sit down and write 500 more. This is obviously more exhausting than just sitting down and writing a full essay, but my brain starts lagging, so I have to move.
This idea is also interesting in light of a recent paper that found stimulants affect arousal, but not focus, and the fact that there are currently ADHD drugs in development that target wakefulness through the orexin system, drugs originally green-lit for narcolepsy.
“Til now, people were always looking toward ADHD from the perspective of attention,” Rahimi says. “I am not saying don’t look at it from that perspective. I am saying there is another aspect, which is energy.”
The hyperactive adults also had hyperactive kids!
Rahimi is very careful to note that this is not a theory about what causes ADHD, and it doesn’t displace current theories, but rather acts as an overarching framework for thinking about and studying ADHD.