ADHD

Stimulant medications — amphetamine salts, methylphenidate — remain first-line. They work fast and they work well for many people. But they wear off every day, the side effects compound (appetite suppression, insomnia, cardiovascular strain), and they don't address the underlying neurobiology. Non-stimulant options like atomoxetine and guanfacine exist but are less effective. Behavioral interventions help with coping but don't change the brain's baseline state.

Granpeesheh et al. (2010) published a study in BMC Pediatrics examining hyperbaric oxygen therapy in children with neurodevelopmental conditions including attention deficits. At 1.3–1.5 ATA, children showed improvements in attention, cognitive awareness, and speech as measured by standardized behavioral scales. The proposed mechanism was enhanced oxygen delivery to hypoperfused frontal regions.¹

SPECT imaging studies by Amen et al. (2012), published in the Journal of Psychoactive Drugs, demonstrated that ADHD brains show characteristic hypoperfusion in the prefrontal cortex. HBOT at mild pressures directly addresses this perfusion deficit. While not an HBOT intervention study itself, it established the vascular rationale for oxygen therapy in ADHD — the same frontal regions that underperform are the ones most responsive to increased oxygenation.²

Tal et al. (2017) showed in a prospective trial published in PLOS ONE that HBOT at 1.5 ATA improved cognitive function — including sustained attention and processing speed — in patients with mild traumatic brain injury. The cognitive domains improved are the same ones impaired in ADHD, suggesting a shared mechanism of frontal lobe oxygen metabolism.³

Hallowell et al. (2019) published findings in the Journal of Neurotherapy examining transcranial photobiomodulation in adults with ADHD symptoms. Near-infrared stimulation at 810 nm applied to the prefrontal cortex produced measurable improvements in sustained attention and executive function on standardized neuropsychological tests.⁴

Gonzalez-Lima and Barrett (2014) demonstrated in Neuroscience that transcranial infrared laser stimulation at 1064 nm improved prefrontal cortex oxygenation and cognitive performance — specifically sustained attention and working memory — in healthy adults. The effect was mediated by enhanced cytochrome c oxidase activity in frontal neurons, the same metabolic pathway that's underactive in ADHD.⁵

Blanco et al. (2017) replicated and extended these findings in Cerebral Cortex, showing that a single session of transcranial infrared stimulation improved executive function and rule-based learning. The authors confirmed increased prefrontal oxygenated hemoglobin via fNIRS during treatment.⁶