Detective Health · Functional Medicine for Adult Neurodivergence

The diagnosis is not
the destination.

Most adults with ADHD, autism or anxiety have waited years for a diagnosis and been offered medication as the primary intervention. That addresses the symptom. It doesn't address why the brain isn't working the way it should. We do the second part.

Take the Free Biochemical Screen → How it works
5
Tests covering the full mechanism
900+
Biomarkers cross-referenced
4
Biochemical root cause clusters
37
Years clinical experience
The problem with current neurodivergent care

A diagnostic label is not a clinical answer.

The current pathway for adult ADHD, autism and anxiety is built around diagnosis and medication. For many people it provides meaningful relief. But for a significant proportion, medication either doesn't work, works partially, or creates new problems — because the underlying biochemistry driving the symptoms was never investigated.

The question that almost never gets asked is: why is your dopamine system not functioning optimally? Why is your nervous system dysregulated? What is actually producing these symptoms in your specific body?

The scale of the gap

A system that was not built for this.

Adult ADHD diagnosis and treatment in the UK is in crisis. But the structural problem runs deeper than waiting times — it's that the entire medical model for neurodivergence is built around behavioural observation and pharmaceutical intervention, with almost no investigation of the underlying biochemistry.

2–3
Year NHS Wait
Average waiting time for an adult ADHD assessment on the NHS. Many areas are significantly longer. The Right to Choose pathway has improved access but remains inconsistent.
£1.5k+
Private Diagnosis Cost
A private ADHD or autism assessment typically costs £1,500–2,500 and concludes with a diagnosis — and a prescription. The biochemical investigation that determines why still doesn't happen.
0
Tests Run
The number of functional laboratory tests typically ordered as part of a standard ADHD or autism assessment. Neurotransmitter metabolites, gut barrier integrity, methylation status — none of these are investigated.
The four root cause clusters

What's actually driving your symptoms — and how we find it.

ADHD, autism and anxiety are not single-cause conditions. They are clusters of neurological symptoms with multiple possible biochemical drivers. The TDG five-test programme identifies which of these are active in your body — and targets them specifically.

Cluster 01 · Neurotransmitter System
Dopamine & Norepinephrine Deficit
OAT · DUTCH Plus
The Organic Acids Test directly measures neurotransmitter metabolites — HVA (dopamine turnover), VMA (norepinephrine/epinephrine), 5-HIAA (serotonin), and the kynurenine pathway markers (quinolinic and kynurenic acid). These are not inferred signals; they are direct biochemical evidence of how your neurotransmitter systems are actually functioning. DUTCH Plus adds cortisol-dopamine axis data and methylation markers. This is what stimulant medication targets — but without knowing why these systems are depleted, medication is treating the deficit without addressing its cause.
Cluster 02 · Gut–Brain Axis
Barrier Integrity, Dysbiosis & Opioid Peptides
GI-MAP · Food Sensitivity
When gut barrier integrity is compromised (elevated zonulin on GI-MAP), incompletely digested casein becomes casomorphin and gluten becomes gliadorphin — both opioid peptides that cross a compromised blood-brain barrier and bind opioid receptors. This mechanism is one explanation for why gluten and dairy elimination produces meaningful symptom improvement in some autism presentations. Additionally, dysbiotic gut bacteria cannot synthesise adequate aromatic amino acids — the precursors your dopamine and serotonin are built from. Glyphosate specifically disrupts this pathway. 90% of serotonin is produced in the gut, not the brain.
Cluster 03 · Methylation & Genetic Expression
MTHFR, B12, Folate & Monoamine Synthesis
Blood Chemistry · DUTCH
MTHFR gene variants are significantly overrepresented in neurodivergent populations. Methylation is the upstream process for all monoamine neurotransmitter synthesis — dopamine, norepinephrine, serotonin. When methylation is impaired, neurotransmitter production is compromised regardless of what precursors are available. B12 and folate status (blood chemistry), homocysteine (methylation marker), and the DUTCH methylation markers (8-OHdG, DHEA-S) together give a comprehensive methylation picture. Zinc-copper dysregulation — another consistent finding in autism spectrum presentations — affects dopamine beta-hydroxylase, the enzyme that converts dopamine to norepinephrine.
Cluster 04 · Metabolic Dysregulation
Blood Glucose, Insulin & Prefrontal Cortex Function
Blood Chemistry
The prefrontal cortex — the seat of executive function, attention, working memory, and impulse control — is exquisitely sensitive to blood glucose. A fasting glucose of 5.8 mmol/L looks "normal" on standard testing. In functional medicine, it signals early insulin resistance that is already affecting prefrontal cortex function. Blood glucose instability directly triggers cortisol release, which disrupts the dopamine system further. Low ferritin (below 30) — extremely common and routinely missed — independently impairs dopamine transport. These are measurable, correctable deficits. They are almost never investigated in standard ADHD care.
The Detective Health approach

We don't start with the diagnosis.
We start with the biochemistry.

A diagnostic label tells you what your symptom pattern is called. It doesn't tell you why your brain is producing those symptoms in your specific body. The TDG programme investigates the why — and builds a protocol around the answer.

Capability Standard Neurodivergent Assessment Detective Health TDG Programme
Neurotransmitter metabolite measurementNot assessed — behavioural observation onlyOAT: HVA, VMA, 5-HIAA directly measured
Gut-brain axis investigationNot assessedGI-MAP: zonulin, dysbiosis, H. pylori, parasites
Methylation statusNot assessedBlood chemistry + DUTCH methylation markers
Blood glucose and insulin patternNot assessedFasting glucose, insulin, HbA1c, HOMA-IR, ferritin
Food reactivity (gluten/casein opioid pathway)Not assessedIgG food sensitivity panel: 200+ foods
Cortisol and HPA axis functionNot assessedDUTCH Plus: diurnal cortisol, CAR, DHEA-S
Protocol outcomeDiagnosis + medication prescriptionBiochemical protocol targeting identified root causes
"I don't start with the question 'do you have ADHD?' I start with the question 'why is your dopamine system not working, and what in your biochemistry is causing that?' The answer is almost always measurable, addressable, and nothing to do with the diagnostic label."
Stephen Duncan FDN-P MSc · Edinburgh
01
Biochemical Screen — Free
18 questions identifying your dominant biochemical cluster: neurotransmitter deficit, gut-brain axis, methylation, or metabolic dysregulation. Identifies which of the five TDG tests are most relevant to your presentation. Free, 3 minutes, results immediately.
02
Discovery Consultation — £145
One hour with Stephen. Your full health history, symptom pattern, and biochemical screen results reviewed together. The appropriate testing pathway identified. An immediate clinical framework for your presentation, and a clear next step.
03
TDG Five-Test Investigation — From £3,500
The complete programme: all five tests simultaneously, full clinical analysis, and a structured protocol built from your biology. For most neurodivergent presentations, the OAT, GI-MAP, blood chemistry and DUTCH Plus are the primary investigative tools. Food sensitivity and extended blood panel as indicated.
Your journey

What actually happens

01
Take the Biochemical Screen
18 questions identify your dominant root cause cluster and which tests are most relevant to your presentation. Free, immediate results.
Free · 3 minutes
02
Discovery Consultation
Your history, symptoms and screen results reviewed with Stephen. Testing pathway confirmed. An immediate clinical framework for your presentation.
£145 · 1 hour
03
Five-Test Investigation
Test kits posted to you. Blood draw at your nearest clinic. All relevant tests run in parallel. Results typically returned within 2–3 weeks.
From £3,500 · 4–6 weeks
04
Protocol & Follow-Up
A structured clinical protocol built from your test findings. Nutrition, supplementation, and lifestyle sequenced to address root causes in the right order.
Ongoing · Periodised
Start here

The Detective Health Neurodivergent Consultation

£145
Discovery Consultation — Everything included
  • Free Biochemical Screen (your starting point — identifies your dominant cluster)
  • Full clinical intake — 12 forms covering your complete health picture
  • Health Status Report compiled by Stephen before your session
  • One-hour consultation with Stephen Duncan FDN-P MSc
  • Root cause cluster analysis with clinical explanation
  • Personalised testing pathway — which of the five tests are most relevant to you
  • Immediate nutritional and lifestyle framework based on your presentation
  • Written summary and next steps after your session
Book Your Consultation →

Secure booking via Practice Better · Cancel or reschedule 48+ hours in advance

Stephen
Duncan
FDN-P · MSc · Edinburgh
37 years clinical experience
Functional Diagnostic Nutrition Practitioner
Metabolic Typing Advanced Practitioner
Co-founder, Omnos Health
(integrated with Regenerus Labs)

"The clients I see with ADHD, suspected autism or treatment-resistant anxiety almost all have something measurable driving their symptoms — and almost none of it has ever been looked for."

I started seeing a pattern years before I had the language for it: clients whose neurological symptoms — attention, mood dysregulation, anxiety, sensory overload — improved dramatically when we addressed what was happening in their gut, their blood chemistry, and their stress hormone systems. Not because I'd treated their ADHD, but because I'd improved their biology.

The mechanisms are now well-documented. Gut dysbiosis impairs neurotransmitter precursor synthesis. Compromised gut barrier allows opioid peptides from gluten and casein to reach the brain. Low ferritin impairs dopamine transport. Blood glucose instability disrupts prefrontal cortex function. Methylation dysfunction starves the monoamine synthesis pathway. These are not alternative medicine claims — they are measurable biochemical processes.

The TDG programme doesn't diagnose ADHD or autism. What it does is investigate the biochemistry that is — or isn't — supporting your brain's optimal function. That investigation almost always reveals something actionable.

Start here

Find out what's actually happening.

Take the free biochemical screen. Three minutes. Identifies your dominant root cause cluster and which tests are most relevant to your presentation.

Take the Free Screen → Book Consultation — £145