The Biology of ADHD — a Series
ADHD is not one thing.
A common assumption is that the condition has a single cause and a single story. Our research points to something more granular: four distinct biological strands can underlie ADHD-related symptoms — a prefrontal energy deficit, an immune-driven neuroinflammatory subset, a dopamine-Nrf2-NLRP3 axis, and acquired features that are not developmental. Different patients likely carry different combinations of these, and each contributes a different slice of the daily symptom burden.
This series examines each strand in plain language, then asks the question they all converge on: can several pathways be treated at once to remove or dampen symptoms and give the patient a more normal life?
1 What we know, what our research adds
Every article in this series distinguishes two things clearly:
- What we know — established scientific findings, cited to the peer-reviewed literature. This includes ADHD’s own well-established science — its core dopamine neurobiology (Volkow et al. 2011), its genetic architecture and overlap with autism Lai et al. (2019), and its standard treatments — alongside the cross-disease findings (the prefrontal hypometabolism in ADHD (Zametkin et al. 1990), the inverted-U catecholamine pharmacology (Arnsten 2011), and the debated adult-onset trajectory Asherson and Agnew-Blais (2019)).
- What our research adds — the hypotheses our documentation project developed by reading across disease boundaries, and which are not yet established: the prefrontal-energy convergence model, the multi-pathway treatment hypothesis, the acquired-reversible framing, and the dopamine-Nrf2-NLRP3 cross-disease axis.
The distinction matters because the two are not the same confidence. “What we know” is evidence; “what our research adds” is testable hypothesis. The series keeps them separate so you are never misled into treating a hypothesis as a finding.
Each article follows the same shape:
- What it is — the mechanism, in ordinary words.
- The evidence — what supports it, and how strong that evidence is.
- The honest limits — what it does not claim.
- The decisive experiment — how the idea could be confirmed or refuted.
2 Part 1: ADHD as a Prefrontal Energy Disorder — and the Multi-Pathway Treatment Hypothesis
The series opens with the most developed strand: a prefrontal cortex running on a thin fuel supply. The prefrontal cortex is the most energy-expensive region in the human brain, so it is the first to degrade under any energy scarcity. Five independent lines — blood-flow failure, glucose hypometabolism, creatine depletion, catecholamine deficit, and an epidemiological gradient — converge on this single point. Part 1 also carries the series’ synthesis: the multi-pathway treatment hypothesis, and what treating several mechanisms at once could mean.
Read the article:
- ADHD as a Prefrontal Energy Disorder: Five Lines of Evidence, One Mechanism — what ADHD is on its own, the cerebrovascular, glucose, creatine, and catecholamine evidence, the epidemiological gradient, the honest limits, the decisive experiment, the slow-but-accurate open question, and the multi-pathway treatment hypothesis.
3 Part 2: The Immune and Neuroinflammatory Strand of ADHD
Not all ADHD may have the same cause. A growing line of evidence links ADHD-like features to chronic neuroinflammation and microglial activation — an immune-driven process that can deplete dopamine and degrade the same prefrontal circuits that primary ADHD affects through development. If some ADHD-like symptoms are driven by inflammation, they may be acquired, reversible, and identifiable.
Read the article:
- The Immune and Neuroinflammatory Strand of ADHD: When Inflammation Shapes Attention — the microglial evidence, the dopaminergic depletion route, the shared pro-inflammatory signal, the orexin-dopamine bridge, the kynurenine-dopamine bridge, the same-root hypothesis, and the honest limits.
4 Part 3: The Dopamine-Nrf2-NLRP3 Axis
A third strand links dopamine biology to the cell’s antioxidant-defense system and to the immune system’s central inflammatory switch. Low dopamine tone impairs Nrf2-driven antioxidant defenses, which in turn removes a brake on NLRP3-inflammasome activation — and the resulting inflammation further depletes dopamine, closing a self-amplifying loop. This cross-disease axis may explain why people with ADHD carry a lower threshold for post-infectious fatigue.
Read the article:
- The Dopamine-Nrf2-NLRP3 Axis: An Inflammatory Loop Behind ADHD and Fatigue — the dopamine-Nrf2 link, the Nrf2-NLRP3 brake, the feedback to dopamine synthesis, the BH4 bottleneck, ADHD’s own genetic architecture and its overlap with autism, the shared mitochondrial-genetic strand (haplogroup U, cybrid evidence), and the testable predictions.
5 Part 4: Acquired vs. Developmental — When ADHD-Like Features Might Be Reversible
The clinically consequential question: are ADHD-like features necessarily present from development, or can some be acquired — and therefore reversible? Much adult ADHD is not a straightforward continuation of childhood ADHD — some is adolescent-onset, some reflects missed or misrecalled childhood symptoms, some is explained by substance use or comorbidity — and acquired inattention after an immune trigger can be reversible when its cause is treated. Telling the two apart determines whether a symptom might respond to treating its cause or is stable wiring.
Read the article:
- Acquired vs. Developmental: When ADHD-Like Features Might Be Reversible — the adult-onset trajectory, the Architecture A/B/C framings, the interoceptive and neuroinflammatory routes, and the clinical consequences of getting the distinction wrong.
6 A note on honesty
Every article in this series distinguishes carefully what is confirmed by evidence, what is a promising hypothesis, and what is an individual patient’s experience. Most of the content here is at the hypothesis end — the certainties are explicit, often low, and nothing is presented as established clinical fact or a treatment recommendation.
The underlying science is drawn from our documentation project, which develops these cross-disease energy and immune models in detail. The ADHD-specific framing is our reading of the literature, written to stand alone for anyone curious about the biology.
Discuss any medical decision with a qualified clinician.