What Organic Acids and Amino Acid Testing Reveal About Anxiety, Depression, and Sleep

The Patient Who Has Already Tried Everything

You have probably seen this patient more times than you can count. They come to you after years of working through everything their prior providers had to offer: SSRIs that helped for a while and then stopped, benzodiazepines they are understandably terrified to stay on long-term, and rounds of cognitive behavioral therapy that helped them understand their anxiety intellectually but did nothing to make them feel better in their body. Their sleep is fragmented, their mood is either flat or volatile depending on the day, and they describe their experience as living under a constant low-grade sense of dread that no one has been able to fully explain to them.

Their conventional labs are unremarkable. The thyroid panel is “within normal limits”. CBC is clean. Every prior provider has told them that what they are dealing with is stress, which is both technically true and almost entirely unhelpful as a clinical framework. Stress is a description of an experience, not a mechanism, and without understanding the mechanism you cannot build a treatment that actually holds.

This is the gap where so many skilled and well-trained practitioners find themselves stuck, and I want to say plainly that this is not a reflection of clinical intelligence or effort. It is a reflection of not yet having access to a testing framework sophisticated enough to reveal what is actually happening in the underlying biochemistry. Once you have that framework, cases that felt like guesswork start to make sense. Not all of them, but most.

Ready to move beyond guesswork? The KICP Longevity Certification teaches practitioners to decode complex lab data and design sequenced protocols using the three-stage model. Enroll at kalishinstitute.com/classes/2026-kicp-longevity-microbiome-brain-health

Why Stress Is Rarely the Actual Problem

Here is something I have come to understand across more than thirty years of clinical practice: when a patient's primary presentation is anxiety, sleep disruption, or depression that has not responded to standard interventions, the word stress is almost always a placeholder for something we have not yet measured.

The nervous system does not exist in isolation. It is downstream of metabolic function, and the same biochemical disruptions that impair mitochondrial energy production, compromise gut barrier integrity, and drive systemic inflammation will also disrupt neurotransmitter balance. All this throwing off sleep, mood and energy levels. These are not separate problems that happen to coexist. They are the same problem expressing itself through different systems.

The challenge for most practitioners is that neither conventional psychiatry nor most functional medicine training programs provide a coherent, lab-grounded framework for pulling these threads together in a clinically actionable way. You may have learned about the gut-brain axis as a concept. You may understand that the HPA axis plays a role in anxiety. But knowing these things conceptually and being able to look at a patient's Organic Acid Test and Amino Acid panel together, in a way that generates a precise, targeted, and sequenced treatment plan, are two very different clinical competencies, and that second competency is what actually gets these patients better. It took me several decades of active study with the top people in our field to understand these treatments and I’ve taken them and put together simple to understand training programs to pass this information on to the next generation. 

The Architecture of Neuro-Inflammation

What the Organic Acid Test Tells You That Nothing Else Can

The OAT is one of the most underutilized tools in functional medicine, particularly for neuropsychiatric presentations. Most practitioners who order it are focused on the mitochondrial markers or the dysbiosis indicators, and those matter. But for the patient whose primary complaints are anxiety, mood dysregulation, insomnia, the neurotransmitter metabolite section of the OAT is where the clinical story begins. Here is what I look at first, and what each marker is actually telling you:

• VMA and HVA (vanilmandelic acid and homovanillic acid) reflect catecholamine activity, specifically dopamine and norepinephrine turnover. These tell you whether the patient is burning through their catecholamines faster than they can replenish them, which shows up clinically as anxiety with exhaustion rather than anxiety with energy. And in one strange and hard to understand result of catecholamine problems is an over activity of the brain, we end up with too many thoughts, thoughts we can’t shut down and balancing out these brain chemicals has both a calming and energizing impact.
• Quinolinic acid and kynurenic acid reveal the status of the kynurenine pathway, which competes directly with serotonin synthesis for the amino acid tryptophan. When you see elevated quinolinic acid, you are not simply seeing a number out of range. You are seeing a patient whose inflammatory burden has shifted tryptophan metabolism away from serotonin and toward a neuroexcitatory pathway that drives anxiety, disrupted sleep, and over time, significant depressive symptoms. This is also a mechanistic explanation for why SSRIs provide incomplete relief in so many of these cases. You cannot meaningfully raise serotonin activity through reuptake inhibition when the upstream substrate is being shunted away by an inflammatory kynurenine pathway in overdrive. 
• 5-HIAA (5-hydroxyindoleacetic acid), the primary serotonin metabolite, adds another layer. Elevated 5-HIAA may indicate compensatory serotonin production under chronic stress. Very low 5-HIAA alongside elevated quinolinic acid is a pattern I have seen repeatedly in treatment-resistant anxiety and sleep-onset insomnia, and it has very specific treatment implications once you know what you are looking at.

Where Amino Acid Testing Completes the Picture

The OAT tells you what is happening to neurotransmitters after they are synthesized, through metabolites that are in a sense proxies. The Amino Acid markers tell you whether the raw materials are available to build them in the first place. These two tests together give you both sides of the metabolic equation, and using one without the other leaves meaningful clinical information on the table. The key precursors I focus on:

• Tryptophan is the precursor to serotonin, and with low plasma tryptophan alongside elevated quinolinic acid on the OAT, you start to have a mechanistic explanation that guides treatment directly: inflammatory cytokines are upregulating the IDO enzyme, pulling tryptophan into the kynurenine pathway rather than allowing its conversion to 5-HTP and ultimately serotonin. This is not a serotonin deficiency in the conventional sense. It is an inflammation-driven diversion of substrate, and it requires a completely different treatment approach than simple precursor loading. You can visually see, on these tests, neuroinflammation driving amino acid markers out of range. That’s pretty amazing.
• Tyrosine and phenylalanine are dopamine, epinephrine and norepinephrine precursors. The amino acid to tyrosine level gives you insight into dopamine precursor availability, which maps directly to the patient who presents with anxiety alongside low energy, low motivation, and difficulty concentrating. Their dopamine signaling is limited, and you can see it on the test in the form of an amino acid deficiency state.

The KICP Longevity Certification covers lab interpretation, hands-on protocol design, and live case reviews with Dr. Kalish. Gain the clinical framework to decode OAT, Amino Acid, and microbiome data in complex neuro-inflammatory presentations. Enroll at kalishinstitute.com/classes/2026-kicp-longevity-microbiome-brain-health

The Systems-of-Systems Framework: Why a Single Protocol Will Not Get You There

Complex Neuro-Inflammatory Cases Require a Different Kind of Thinking

One of the things I was taught by my mentors was to synthesize and integrate lab data across different labs and to correlate that all with patient symptoms. Using this approach then to design impactful lifestyle and supplement programs based on a body systems approach. A protocol says: if the patient has anxiety, run this test and give this supplement. A systems  framework says I need to understand what is happening across several body systems simultaneously before I can build a treatment strategy that will work over the long term.

In practice, when you are evaluating a patient with treatment-resistant anxiety using OAT and Amino Acid testing, you should be looking across three interconnected systems at once:

• The hormonal system (adrenal and reproductive hormones): HPA dysregulation directly modifies the activity of tryptophan hydroxylase, the rate-limiting enzyme in serotonin synthesis. You cannot optimize neurotransmitter metabolism in a patient whose cortisol axis is dysregulated.
• The GI system (microbiome, barrier function, digestive capacity): Gut microbiome disruption drives LPS-mediated systemic inflammation, which is one of the primary activators of the kynurenine pathway. The gut is often where the neuro-inflammatory cascade begins.
• The metabolic and detoxification system (mitochondrial function, oxidative stress burden, neurotransmitter metabolism): Mitochondrial dysfunction impairs the energy-dependent processes of neurotransmitter synthesis and synaptic reuptake, which is why the mitochondrial section of the OAT is never separate from the neurotransmitter picture.

Most complex neuro-inflammatory presentations involve disruption across at least two of these systems, and effective treatment requires addressing them in the right sequence.

Clinical Sequencing: The Variable That Changes Outcomes Most

One of the most common mistakes I see practitioners make with complex presentations is treating the neurotransmitter findings first, before addressing the inflammatory and gut-based drivers that are perpetuating the biochemical disruption. I have made this mistake myself many times in practice and I continue to make this same mistake because it’s super tempting to use a quick fix that will lead to significant symptom relief and convince yourself that’s work out in the long run. Plus, neurotransmitter findings are often the most dramatic markers on the panel and the human instinct is to treat what looks most urgent.

But if quinolinic acid is elevated because of gut-sourced inflammation, providing tryptophan supplementation may produce modest and temporary symptom relief while doing little to shift the underlying mechanism. You are adding substrate to a pathway that is being actively diverted by inflammatory signaling you have not yet addressed. The general sequencing principle I teach is: address the gut-sourced inflammation and adrenal dysregulation in the begining, if you want to provide some quick relief add in amino acids for brain support then go for it, but don’t start with brain treatments all on their own if there is significant neuroinflammation present. 

What This Looks Like in Practice

A doctor in one of our training cohorts brought a case to a live mentorship call that illustrates all this. Her patient was a woman in her late thirties with a longstanding diagnosis of generalized anxiety disorder who had been on a low-dose SSRI for about two years. The medication had helped somewhat but left her with persistent sleep-onset insomnia and what she described as a buzzing physical sensation she could not turn off, even on days when she had nothing particular to worry about. The doctor had run a comprehensive GI test and completed a  standard functional medicine intake but was uncertain about where to go next.

When we ran an OAT and Amino Acid panel and found:

• Quinolinic acid elevated well above reference range
• Plasma tryptophan low
• 5-HIAA low, consistent with impaired serotonin synthesis
• HVA below optimal, suggesting impaired dopamine
• Mitochondrial markers (elevated succinate and citrate) indicating impairment there also

The treatment strategy we developed together did not start with 5-HTP or tryptophan. It started with addressing the gut-sourced inflammatory drivers, supporting mitochondrial function, and stabilizing the adrenal axis. Only after two months of that foundational work did we introduce amino acid support for serotonin and dopamine precursors. At the six-month follow-up OAT, quinolinic acid had normalized, the mitochondrial markers had improved substantially, and 5-HIAA was moving toward the optimal range. Her sleep had stabilized, her anxiety was significantly reduced, and she was in conversation with her prescribing physician about a gradual SSRI taper. This is what it looks like when the lab data guides the clinical logic rather than the other way around.

Key Takeaways for Practitioners

• Elevated quinolinic acid on the OAT signals kynurenine pathway activation from inflammatory burden and indicates impaired tryptophan availability for serotonin synthesis. This is not a simple deficiency state and should not be treated as one.
• Low plasma tryptophan alongside low 5-HIAA confirms upstream substrate limitation and requires an inflammatory workup before precursor supplementation will produce durable results.
• HVA and VMA patterns distinguish dopamine-insufficient presentations from hyperadrenergic anxiety states, and this distinction changes treatment targets meaningfully.
• Sequence matters more than most practitioners realize: address gut-sourced inflammation and adrenal dysregulation before optimizing neurotransmitter precursors, or the treatment will produce limited and temporary results.
• Using OAT and Amino Acid testing together gives you both sides of the metabolic equation: what is happening downstream to neurotransmitter metabolites, and whether precursor substrates are available upstream.

Frequently Asked Questions

What is the difference between running an OAT alone versus integrating it with Amino Acid testing for neuropsychiatric presentations?

The OAT shows you what is happening to neurotransmitters after synthesis through metabolite proxies, while Amino Acid testing shows you whether the precursor substrates are available upstream of synthesis. Using them together gives you both sides of the metabolic equation and substantially improves your ability to identify the mechanism driving the patient's presentation rather than just observing its downstream effects. And yes, you can have normal OAT markers and still have amino acid deficiencies so you’ll miss a lot of people if you don’t screen for amino acids and yes you can have low amino acid levels for tyrosine and tryptophan and the brain markers can be just fine. It’s confusing the say the least even with both tests and with only one to go on it’s even more confusing. 

Can this framework be applied to patients who are already on psychiatric medications?

Yes, but you need a lot of experience to do this and if you try to use amino acids with people on medications you can make them a lot worse so don’t try it unless you have someone with a lot of training to step you through the process. 

How does the kynurenine pathway relate to neuro-inflammation specifically?

Inflammatory cytokines including IL-6, TNF-alpha, and interferon-gamma upregulate the IDO enzyme, which diverts tryptophan into the kynurenine pathway rather than the serotonin pathway. Quinolinic acid, a downstream kynurenine metabolite, is itself neuroexcitatory and neurotoxic at elevated concentrations, which is why chronic inflammation produces both serotonin depletion and direct excitotoxic pressure on neuronal tissue simultaneously.

Is this approach appropriate for practitioners across different licensing backgrounds?

The framework is applicable across a wide range of clinical backgrounds including MDs, DOs, NPs, PAs, chiropractors, acupuncturists, and allied health providers working within their clinical scope. The training to interpret these labs with confidence and translate findings into treatment plans is what the Kalish Institute's mentorship programs are specifically designed to provide, regardless of your prior training background.

What is the most common sequencing mistake practitioners make with these cases?

Treating the neurotransmitter markers on their own, without addressing the gut and inflammatory drivers that are perpetuating the biochemical disruption. 

The Method Is What Makes the Difference

After more than thirty years of clinical practice and training more than 10,000 practitioners globally, the thing I keep returning to is this: most of the practitioners who feel stuck with complex cases are not lacking in intelligence, care, or clinical experience. They are working without a framework systematic enough to match the complexity of what they are seeing. And that is a solvable problem.

The integration of Organic Acid and Amino Acid testing for neuro-inflammatory presentations is not a niche specialty interest. It is, in my view, one of the most clinically impactful skills a practitioner can develop right now, given how many patients are presenting with exactly this constellation of symptoms and finding no lasting resolution in conventional care. When you can show a patient the metabolic mechanism behind what they have been experiencing, and then build a treatment plan that addresses that mechanism directly, something shifts for them beyond the symptom relief. They understand what was happening, and they trust the process.

That is the goal, and it is teachable. Understanding the framework is the starting point. Learning to apply it with precision across real cases, with the pattern recognition that comes from supervised clinical experience and mentorship, is what the Kalish Institute's programs are built to provide.

Enrollment Is Open: KICP Longevity Certification

The KICP Longevity Certification is designed for licensed practitioners who are ready to move from understanding functional concepts to confidently designing protocols that drive real patient results. This certification program covers the microbiome-brain health connection through a systems-based, lab-grounded clinical framework. 

The curriculum includes:

• Advanced lab interpretation integrating OAT, Amino Acids, microbiome, and brain health markers.
• Hands-on protocol design moving from lab report to customized, sequenced treatment plans.
• Live case reviews with Dr. Kalish to work through real patient presentations in real time.
• Access to recorded curriculum plus live cohort calls and all course materials.

Enroll Now: KICP Longevity Certification