ADHD: The Functional Medicine Approach

ADHD as Brain Underactivation

The name is a lie. “Attention Deficit Hyperactivity Disorder” implies excess — too much energy, too much movement, too much noise. The reality is deficit. The ADHD brain is underactivated in the prefrontal cortex — the region responsible for executive function, impulse control, working memory, planning, and emotional regulation. Dopamine and norepinephrine levels in the PFC are insufficient to maintain tonic firing of these circuits.

The hyperactivity, the fidgeting, the thrill-seeking, the inability to sit still — these are the brain’s desperate attempts to stimulate itself. The child who cannot stop moving is not misbehaving. She is self-medicating. This is why stimulant medications (methylphenidate, amphetamines) work paradoxically — they increase dopamine and norepinephrine in the PFC, finally giving the brain the activation it has been seeking through external chaos.

But the functional question is not “how do we increase dopamine?” It is “why is dopamine insufficient in the first place?” And there, the answers multiply.

IFM Root Causes

Nutrient Deficiencies

Iron: This is the most underappreciated nutrient in ADHD. Ferritin below 30 ng/mL correlates directly with ADHD severity (Konofal 2004). The reason is biochemical: iron is an essential cofactor for tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis. No iron, no dopamine. Period. The standard “normal” range for ferritin (12-150) is misleading — a ferritin of 15 is “normal” by lab range but catastrophically low for dopamine production. Target: ferritin above 50, ideally 70-100.

Zinc: 30-50% of children with ADHD are zinc deficient. Bilici 2004: zinc supplementation added to methylphenidate was significantly superior to methylphenidate alone. Zinc is a cofactor for over 300 enzymes including those involved in neurotransmitter synthesis, immune function, and fatty acid metabolism. It modulates dopamine transporters and melatonin synthesis (zinc deficiency → poor sleep → worsened ADHD).

Magnesium: Calms neuronal excitability by blocking NMDA receptors and modulating calcium channels. The ADHD brain is already hyperexcitable (paradoxically — underactivated PFC but overexcitable sensory and emotional circuits). Magnesium provides the brake.

Omega-3 fatty acids: DHA constitutes 40% of neuronal membrane phospholipids. It maintains membrane fluidity, which determines how efficiently neurotransmitter receptors function. EPA provides anti-inflammatory action in the brain. Bloch and Qawasmi 2011 meta-analysis confirmed a small but significant effect of omega-3 supplementation on ADHD symptoms. The effect size is modest compared to stimulants but meaningful, especially when combined with other interventions.

B6/P5P: Cofactor for aromatic amino acid decarboxylase — the enzyme that converts L-DOPA to dopamine and 5-HTP to serotonin. Also essential for GABA synthesis.

Vitamin D: Receptors throughout the brain including the prefrontal cortex. Low vitamin D is consistently associated with ADHD in population studies.

Food Sensitivities and Additives

This is where the evidence is surprisingly strong. The Feingold diet — removing artificial colors, artificial flavors, and preservatives — was proposed in the 1970s and dismissed as quackery. Then the studies caught up.

Pelsser 2011 (published in The Lancet): A restricted elimination diet improved ADHD symptoms in 64% of children. Not a subtle improvement — a 64% response rate. Conventional medications have response rates of 70-80%, so diet alone gets remarkably close.

Specific culprits:

• Red dye 40 (Allura Red): The most commonly used food dye in the US. The EU requires warning labels on foods containing it: “may have an adverse effect on activity and attention in children.”
• Yellow 5 (Tartrazine), Yellow 6, sodium benzoate: All implicated in the Southampton studies.
• Gluten and dairy (casein): Not triggers for all, but a significant subset of ADHD children improve dramatically when these are removed. Casein breaks down into casomorphin — an opioid peptide that crosses the blood-brain barrier.

Blood Sugar Dysregulation

A child who eats a bowl of sugary cereal for breakfast experiences a blood sugar spike followed by a crash at exactly 10 AM — the time when the teacher expects focused attention. The crash triggers adrenaline (to rescue blood sugar), which produces restlessness, irritability, poor concentration, and impulsive behavior. The child gets labeled ADHD. The child has a dietary problem.

Protein at breakfast is not optional — it is foundational. 20g minimum. Eggs, meat, nuts, full-fat yogurt. This creates a slow, stable glucose curve that supports sustained attention.

Gut-Brain Axis

The gut microbiome of ADHD children differs from controls: lower Bifidobacterium, altered Firmicutes-to-Bacteroidetes ratio. Gut inflammation drives systemic inflammation drives neuroinflammation. SIBO is a possible contributor, particularly in children with both GI symptoms and attention problems (a combination far more common than most pediatricians realize).

Heavy Metals

Lead: Even at levels well below the CDC threshold of concern, lead exposure correlates with inattention, impulsivity, and hyperactivity. There is no safe level of lead for neurodevelopment. Sources: old paint, contaminated water (Flint was not an anomaly), imported spices, certain toys and cosmetics.

Mercury: Amalgam fillings, large predatory fish (tuna, swordfish), environmental exposure. Disrupts dopaminergic signaling.

Testing: Blood lead, blood or urine mercury. Hair mineral analysis for chronic exposure patterns.

Thyroid

Generalized resistance to thyroid hormone (GRTH) — a rare but real finding in ADHD subpopulations. Even without GRTH, subclinical hypothyroidism affects prefrontal function. Every ADHD evaluation should include a full thyroid panel: TSH, Free T4, Free T3, reverse T3, TPO antibodies.

Sleep: The Great Mimicker

Sleep deprivation perfectly mimics ADHD: inattention, impulsivity, hyperactivity, emotional dysregulation, poor working memory. In adults, sleep deprivation makes you drowsy. In children, it makes them wired — the adrenal response to fatigue is stimulatory, not sedating.

Undiagnosed contributors:

• Sleep apnea: Enlarged tonsils/adenoids in children — surgical removal improves attention in 50% of cases.
• Restless legs syndrome: Driven by low ferritin. Supplementing iron resolves RLS and improves sleep quality and daytime attention.
• Delayed sleep phase: The ADHD brain naturally shifts toward a later circadian rhythm. Melatonin (0.5-1mg, 30 minutes before target bedtime) can reset the clock.

Prenatal and Early Life Factors

Maternal smoking during pregnancy (nicotine disrupts dopaminergic development), alcohol exposure, maternal stress, premature birth, low birth weight, early antibiotic exposure (microbiome disruption), C-section delivery (missed vaginal microbiome colonization), formula feeding (lacks human milk oligosaccharides that feed Bifidobacteria). These are not modifiable after the fact, but they explain etiology and guide treatment intensity.

Pyrrole Disorder

Elevated urinary HPL wastes zinc and B6 through the kidneys. The result: low GABA, low serotonin, poor stress tolerance, sensory sensitivity. Common in ADHD and often the hidden driver of treatment resistance. Testing: urinary kryptopyrroles. Treatment: zinc 30-60mg + B6/P5P 50-100mg + evening primrose oil.

Phospholipid Deficiency

Cell membranes are built from phospholipids. When phospholipid status is poor, every receptor on every neuron functions suboptimally. Clinical signs: excessive thirst (polydipsia without diabetes), dry skin, bumpy skin on upper arms (keratosis pilaris — those small rough bumps that 40% of the population has and nobody explains), soft or brittle nails.

Phosphatidylserine supplementation directly addresses this.

Testing

• Ferritin: Target above 50 for ADHD, ideally 70-100 (not just “in range”)
• Zinc + copper: The ratio matters as much as the individual levels. High copper with low zinc drives anxiety, inattention, and emotional volatility (Walsh’s copper overload theory).
• RBC magnesium: Serum magnesium is meaningless — 99% of magnesium is intracellular.
• Omega-3 index: Target above 8%.
• 25-OH vitamin D: Target 50-70 ng/mL.
• B12 + methylmalonic acid: MMA elevates before B12 drops below range.
• Full thyroid panel: TSH, Free T4, Free T3, reverse T3, TPO antibodies.
• Fasting glucose + insulin: Rule out insulin resistance and reactive hypoglycemia.
• Lead + mercury (blood): Even “low” levels matter for neurodevelopment.
• OAT (Organic Acids Test): Neurotransmitter metabolites (HVA for dopamine, VMA for norepinephrine), yeast markers (arabinose), mitochondrial markers.
• Food sensitivity panel: IgG and IgE.
• Urinary pyrroles: If pyrrole disorder suspected.
• Stool testing (GI-MAP): If GI symptoms present.

Protocol

Foundation Diet

Remove artificial colors, flavors, and preservatives — completely. This is not negotiable and should be step one before any supplement or medication. Read every label. If it contains Red 40, Yellow 5, Yellow 6, sodium benzoate, BHT, or BHA — it goes.

Reduce or remove refined sugar. This does not mean “sugar causes ADHD.” It means sugar causes blood sugar volatility, which worsens attention in a brain already struggling with prefrontal activation.

Protein at every meal, especially breakfast. 20g minimum. This is the single most impactful dietary change. Protein provides tyrosine (dopamine precursor), stabilizes blood sugar, and promotes sustained attention.

Organic when possible — reducing pesticide exposure. The CHAMACOS study found organophosphate pesticide exposure correlated with ADHD diagnosis.

Core Supplements

• Omega-3: 1-2g EPA+DHA/day in children, 2-3g in adults. EPA:DHA ratio of approximately 2:1 for behavioral benefits (Richardson 2012, Durham trial). Liquid form for children who cannot swallow capsules. Nordic Naturals, Carlson, or other third-party tested brands.
• Iron bisglycinate: If ferritin below 50. Children: 1-2mg/kg/day. Adults: 25-50mg on alternate days (alternate-day dosing increases absorption — Stoffel 2017). Take with vitamin C, away from dairy and calcium. Recheck ferritin at 3 months.
• Zinc: 15-30mg/day children, 30-50mg adults. Take with food to prevent nausea. Zinc picolinate or zinc bisglycinate for better absorption.
• Magnesium: 200-400mg glycinate or L-threonate. Magnesium L-threonate (Magtein) specifically increases brain magnesium levels — it is the only form shown to cross the blood-brain barrier effectively (Slutsky 2010).
• Vitamin D: 1000-2000 IU children, 5000 IU adults. Target 50-70 ng/mL. Test and adjust.

Targeted Supplements

• Phosphatidylserine: 200-300mg/day. Hirayama 2014: improved ADHD symptoms in children, particularly short-term auditory memory and inattention. Phosphatidylserine is a structural phospholipid in neuronal membranes, and supplementation improves membrane integrity and receptor function.
• Pycnogenol (pine bark extract): 1mg/kg/day. Trebaticka 2006: reduced hyperactivity, improved attention and visual-motor coordination, and normalized urinary catecholamine levels (dopamine and norepinephrine) in ADHD children. One of the few supplements that directly modulates catecholamine metabolism.
• L-theanine: 200mg 2x/day. Amino acid from green tea that promotes alpha brainwave activity — calm focus without sedation. Works synergistically with caffeine for adults (the combination improves sustained attention better than either alone). In children, L-theanine improves sleep quality, which improves daytime attention.

Elimination Diet Trial

A 2-4 week trial removing the top reactive foods (gluten, dairy, eggs, soy, corn, artificial additives) plus any foods identified on sensitivity testing. Keep a detailed symptom journal. Then systematically reintroduce one food every 3-4 days, observing for behavioral changes within 24-72 hours.

If this trial produces a clear positive response — and it does in over 60% of cases — you have found a modifiable driver that alone can reduce or eliminate the need for medication. The Lancet published this. It is not fringe.

Sleep Optimization

Address sleep before anything else. A child sleeping six hours cannot focus regardless of how many supplements or medications you give. No screens for one hour before bed — the blue light and the dopaminergic stimulation both disrupt sleep onset. Consistent bedtime routine. Bedroom cool and dark. If sleep onset is delayed: melatonin 0.5-1mg, 30 minutes before target bedtime (lower doses are more effective than higher doses for circadian shifting — Bruni 2015). Check ferritin for restless legs. Consider sleep study if snoring or mouth breathing is present.

Exercise: The Prescription That Writes Itself

John Ratey’s research (documented in his book “Spark”) demonstrated that 30 minutes of moderate aerobic exercise produces effects on attention and impulse control equivalent to a dose of stimulant medication. The mechanism: exercise increases dopamine, norepinephrine, BDNF, and endorphins. It grows new neurons in the hippocampus. It improves executive function.

The timing matters: exercise before school or work has the greatest impact on subsequent attention. Martial arts are particularly effective for ADHD because they combine physical movement with focused attention, self-regulation, and respect for structure — training exactly the circuits that ADHD underactivates.

Neurofeedback

Neurofeedback trains brainwave patterns: increasing beta and sensorimotor rhythm (SMR) activity (associated with focused, calm attention) while decreasing excess theta activity (associated with daydreaming and inattention). Arns 2009 meta-analysis found large effect sizes for neurofeedback in ADHD — comparable to methylphenidate — with lasting benefits that persist after training ends (unlike medication, whose effects cease when you stop taking it).

Typically requires 30-40 sessions over 3-4 months. Insurance rarely covers it. But the effects are durable — this is training the brain, not drugging it.

Medication Integration

The functional approach is not anti-medication. Stimulant medications have the strongest evidence base of any ADHD treatment, and for some children and adults, they are transformative. The functional approach works alongside medications and often allows dose reduction over time as the underlying drivers are addressed.

Critical monitoring with medication:

• Appetite suppression: Stimulants decrease appetite. This creates a vicious nutritional cycle — the medication reduces eating, which reduces nutrient intake (iron, zinc, protein), which worsens the underlying dopamine deficiency, which requires higher medication doses. Break this cycle by prioritizing a high-protein breakfast before medication kicks in, and a nutrient-dense dinner after it wears off.
• Growth: Monitor height and weight in children. Medication holidays during summers can allow catch-up growth.
• Sleep: Stimulants can delay sleep onset. Ensure medication timing allows adequate clearance before bedtime.
• Nutrient repletion: Ensure iron, zinc, magnesium, omega-3, and vitamin D are optimized regardless of medication status.

The most successful ADHD management combines targeted supplementation, dietary optimization, exercise, sleep hygiene, behavioral strategies, and — when needed — the lowest effective dose of medication. Not one or the other. All of it, working together, addressing the whole system.