Photobiomodulation & Brain Fog - Effects on Neurotrainsmitters
James Carroll
JAMES CARROLL (UK)
Founder CEO THOR Photomedicine
James has co-authored 32 academic papers on Photobiomodulation (PBM), six in collaboration with Harvard Medical School. He also contributed chapters to five PBM books. He is a Fellow of The Royal Society of Medicine and a past Chair of the Biomedical Optics Society Conference on Photobiomodulation Mechanisms. James briefed the US Congress and the White House on PBM as a solution to the opioid crisis and presented at the United Nations Global Health Impact Forum. He is on a mission to have PBM installed in every corner of every department of every hospital in the whole world.
James Carroll explores how photobiomodulation, a light-based therapy, influences
We shine light on people and they heal more quickly. It is a proven, effective, and safe treatment that switches on the regenerative effects of your body.
Summary
- Photobiomodulation uses specific wavelengths of light to accelerate tissue repair, reduce inflammation, and provide pain relief by optimizing cellular functions. - The therapy enhances mitochondrial function, increasing ATP production while reducing the oxidative stress and free radicals associated with aging and injury. - Research indicates PBM can reduce neuroinflammation and glial cell activation, offering benefits for dementia, traumatic brain injury, and age-related cognitive decline. - PBM influences neurotransmitters indirectly by triggering secondary cellular messages and transcription factors that improve mood, memory, and cognitive performance. - Clinical trials demonstrate that light therapy can effectively reduce brain fog and improve psychological outcomes in conditions like fibromyalgia, PTSD, and COVID-19 recovery.
Article
Light Against The Haze
At Biohacker Summit 2023 Amsterdam, James Carroll Argued That Photobiomodulation Could Cut Through Brain Fog By Changing The Cellular Conditions That Shape Cognition
In a field crowded with miracle claims and wellness theatrics, James Carroll arrived in Amsterdam with a pitch that sounded, at first hearing, almost too neat to trust. At the Biohacker Summit 2023 Amsterdam, held in the Netherlands on 14 and 15 October 2023, the founder and chief executive of THOR Photomedicine presented a session titled *Photobiomodulation & Brain Fog - Effects on Neurotrainsmitters*. His subject was light, not as metaphor, but as intervention: monochromatic light applied with precision to tissue in order to alter energy production, calm inflammation and, perhaps most provocatively, improve the faltering cognition that patients often call brain fog.
Carroll, who has co-authored 32 academic papers on photobiomodulation, including six with Harvard Medical School collaborators, spoke with the brisk certainty of a man who has spent years defending an idea once dismissed as fringe. He also wrapped that certainty in caveats, disclosures and self-deprecating humour, reminding the audience that he ran a regulated medical device company and that many of the uses discussed remained educational rather than approved indications in some jurisdictions.
Yet beneath the legal disclaimers lay an argument of striking ambition: that photobiomodulation, or PBM, might help conditions as varied as traumatic brain injury, Covid-related cognitive dysfunction, fibromyalgia, PTSD, mild cognitive impairment and age-related decline because it acted not on symptoms first, but on cellular distress.
A Therapy Built On Precision, Not Magic
Carroll reduced the principle to a deceptively simple formula. “If you apply light at the right wavelength and intensity, you can tip the balance of your cells to produce more energy and fewer reactive oxygen species, triggering the body's natural healing mechanisms.”
That sentence did much of the work of the talk. PBM, he explained, uses light of a single colour, delivered at a specific wavelength, intensity, duration and interval. Get those variables right and the therapy can accelerate tissue repair, reduce inflammation and oedema, and produce analgesic effects. Get them wrong and the benefit fades, or even reverses. It was, he suggested, less a miracle than a dosing problem.
The central biological target was the mitochondrion, the cell’s energy engine. In injured, ageing or diseased tissue, mitochondrial function often declines while oxidative stress rises. PBM, Carroll said, appears to shift that equation by increasing ATP production and reducing the excess reactive oxygen species that drive inflammatory cascades. Those cascades, in turn, are implicated in neurodegeneration, chronic pain, impaired recovery and the diffuse mental dullness that so many patients struggle to describe and clinicians struggle to classify.
The Brain Fog Question
Carroll was candid that he had not chosen the title of his presentation, but he met the challenge directly. Brain fog, after all, is a loose term, medically imprecise but experientially vivid. It can mean slowed recall, poor attention, fatigue, emotional bluntness, difficulty organising tasks, or the sensation that thought itself has become effortful.
His answer was that PBM did not appear to manipulate neurotransmitters directly in some crude neurological override. Instead, it seemed to influence them indirectly through what he described as primary and secondary cellular effects. Light is absorbed in the cell, especially in mitochondrial structures such as cytochrome c oxidase. That triggers immediate changes in ATP, reactive oxygen species, nitric signalling and calcium exchange. From there come downstream effects on transcription factors, antioxidant systems, brain-derived neurotrophic factor and broader cell-to-cell communication.
In other words, PBM was presented not as a switch thrown on serotonin or dopamine, but as an intervention that improved the environment in which the brain regulates itself.
Inflammation, Glial Cells And The Ageing Brain
One of the more compelling passages of the talk came when Carroll turned to the ageing brain. He cited research suggesting that long-term PBM reduced glial cell activation in aged mice, bringing markers of brain inflammation closer to what might be seen in younger animals. Astrocytes and microglia, usually discussed in specialist neuroscience circles, entered the stage here as major actors in the story of cognitive decline. Their overactivation is linked to neuroinflammation and neurodegenerative disease.
For Carroll, this mattered because it offered a coherent explanation for why PBM might help not only injury recovery but also mild cognitive impairment and perhaps aspects of dementia. Clinical evidence, he said, already pointed in that direction. Randomised controlled trials, many still small, had shown benefits in conditions including Parkinson’s disease, stroke, traumatic brain injury, PTSD, depression and Covid brain fog.
“Photobiomodulation has a profound effect on reducing mild cognitive impairment associated with aging or traumatic brain injury, helping to improve memory retention, mood, and emotional function,” he said.
It was a large claim, but not delivered as fantasy. Carroll repeatedly framed the evidence as promising rather than complete, pilot-scale rather than definitive. Even so, the cumulative message was unmistakable: if inflammation and energy failure sit near the root of cognitive dysfunction, then light might prove to be a more serious medical tool than many assumed.
Better Blood Flow, More Stem Cells, Sharper Performance
The presentation also ventured into territory likely to excite the summit’s biohacking audience. Carroll described data showing that PBM increased haemoglobin and oxyhaemoglobin in the brain within minutes, suggesting improved cerebral blood flow. He also pointed to studies in which targeting light to bone-rich areas such as the tibia or sternum produced a 300% to 500% rise in circulating stem cells within 24 hours.
“Using the right wavelength and intensity of light can lead to a three hundred to five hundred percent increase in the number of circulating stem cells in the body within twenty four hours of treatment,” he said.
To a sceptic, such figures might sound extravagant. To Carroll, they were evidence that local light application could have systemic effects. Cells, he noted, signal to one another. Tissue that never directly receives light may still benefit from the biochemical messages released by tissue that does.
Then came the performance angle. In one study on healthy students, PBM applied to the right prefrontal cortex improved both speed and accuracy on memory and image-matching tasks immediately after treatment. The result mattered because it extended the discussion beyond illness. PBM was not being pitched only as rescue medicine for damaged brains, but as a tool that might make a healthy brain function more efficiently under cognitive load.
From PTSD To Fibromyalgia, A Broader Psychological Effect
Carroll’s case for PBM reached beyond memory tests and inflammation markers. He cited reductions in PTSD symptoms in a retired NFL player after a six-week treatment course, and a separate study showing reduced opioid cravings after light therapy. These findings fit the broader theme of the session: that by altering cellular stress, blood flow and neuroinflammatory signalling, PBM might improve emotional regulation as well as cognition.
He also discussed fibromyalgia, a condition often marked by pain, distress, fear of movement and a profound collapse in confidence. Here, he said, PBM had been associated not only with lower pain scores but with reduced catastrophising, reduced fear and improved self-efficacy.
“Beyond physical healing, this therapy helps improve self-efficacy and confidence while reducing fear and distress, leading to a significantly higher quality of life for patients,” Carroll said.
What gave these claims extra force was his emphasis on what he called momentum. In some patients, improvements continued after the treatment period ended. Healing, once nudged in the right direction, did not always stop when the light was switched off.
A Once-Fringe Therapy Moves Toward The Mainstream
There was an undercurrent to the session that mattered almost as much as the data itself: the sense that PBM had moved from the margins towards institutional acceptance. Carroll noted that in the UK, the National Institute for Health and Care Excellence had recommended photobiomodulation for oral mucositis in cancer patients, a painful side effect of chemotherapy and radiotherapy. For a therapy long associated in some minds with futuristic promise and commercial overstatement, such endorsements marked a shift.
Carroll, a Fellow of the Royal Society of Medicine and a former chair of the Biomedical Optics Society Conference on Photobiomodulation Mechanisms, has spent years trying to engineer precisely that shift. He has briefed the US Congress and the White House on PBM in the context of the opioid crisis and spoken at the United Nations Global Health Impact Forum. In Amsterdam, that long campaign surfaced in a single clear ambition: to see PBM become standard equipment across hospitals worldwide.
The Promise, And The Discipline It Demands
Still, the most important note in the room may have been restraint. Carroll returned repeatedly to the need for exact dosing. PBM, as he described it, is governed by a Goldilocks principle. Too little light and nothing happens. Enough, and anti-inflammatory, regenerative effects emerge. Too much, and the benefit can disappear.
“By applying monochromatic light at the right intervals, we can increase the speed and quality of tissue repair while reducing inflammation and edema throughout the body,” he said.
That word right did the heavy lifting. Right wavelength. Right intensity. Right place. Right timing. For all the futuristic appeal of treating brain fog with light, Carroll’s argument rested less on spectacle than on calibration.
At Biohacker Summit 2023 Amsterdam, James Carroll did not present photobiomodulation as science fiction made real. He presented it as a therapy with a widening evidence base, a plausible mechanism, and a growing list of clinical and cognitive applications. The boldness of the claims remained matched by the incompleteness of the evidence. But that, perhaps, was the point. In a culture eager for shortcuts, Carroll offered something more demanding and more interesting: a case that light, applied with rigour, might help the brain remember how to heal itself.
Part of Biohacker Summit 2023 Amsterdam