A naturopathic perspective on the hidden physiological roots of common mental health conditions
You’ve tried therapy. Maybe medication. You’ve worked on your mindset, your habits, your relationships. And yet the anxiety or depression keeps returning, or never fully lifts. If that resonates, there’s something important your healthcare team may not have told you: mental health conditions are not always, or only psychological.
As a naturopathic physician, one of the most consistent things I see in practice is people who have been chasing their mental health symptoms for years, never realizing that the body itself is the missing piece of the conversation. Nutritional deficiencies, gut dysfunction, hormonal imbalances, genetic variations, chronic infections, metabolic dysregulation; all of these can directly generate or amplify anxiety, depression, brain fog, and mood instability.
Below is an overview of the most common physiological contributors I look for when someone comes to me with mental health symptoms that haven’t fully responded to conventional treatment. This list is not exhaustive, it’s an invitation to start asking different questions.
1. Nutritional Deficiencies
The brain is the most nutrient-hungry organ in the body, and when key nutrients are depleted, even subtly, the psychological effects can be profound. Iron is required to produce dopamine and serotonin; even without full anemia, low ferritin (iron stores) is strongly associated with fatigue, depression, anxiety, and brain fog. B12 and folate deficiency impair the methylation cycle, the biochemical process that underlies neurotransmitter synthesis, and deficiency in either can produce depression, anxiety, cognitive decline, and even psychosis-like features. Vitamin B12 deficiency is particularly common in vegans, people over 60, and those who take certain common medications like metformin or proton pump inhibitors.
Copper and zinc are equally important and exist in a delicate balance. Elevated copper, which is common in women due to estrogen’s influence on copper retention, and spikes dramatically during pregnancy, directly stimulates the fight-or-flight neurotransmitter norepinephrine while suppressing dopamine, producing a nervous system that is chronically over-stimulated. Zinc deficiency, on the other hand, impairs GABA, the brain’s primary calming neurotransmitter.
Standard bloodwork often misses these issues. Ferritin, for example, may be reported as “normal” at levels far too low for optimal brain function. Requesting a comprehensive functional nutrient panel, including ferritin, B12, folate, homocysteine, and plasma zinc/copper, tells a very different story.
2. Vitamin D Deficiency (and the Genetic Twist)
Vitamin D is technically a hormone, not a vitamin, and it plays a direct role in serotonin synthesis, dopamine regulation, neuroplasticity, and immune modulation. Deficiency is extremely common, particularly in northern climates, and is strongly associated with depression, anxiety, and seasonal mood changes.
But here’s the layer most people don’t know: some people carry genetic variations in the vitamin D receptor (VDR) gene or in the enzymes that convert sunlight into the active hormonal form of vitamin D. These individuals may spend plenty of time outdoors and still experience functional vitamin D insufficiency because their bodies cannot properly convert or utilize what they’re getting. Standard supplementation may not be enough without addressing the conversion pathway.
3. Gut Dysfunction and the Gut–Brain Axis
Approximately 90–95% of the body’s serotonin is produced in the gut, not the brain. When the gut microbiome is imbalanced, a state called dysbiosis, driven by antibiotics, high-sugar diets, chronic stress, or past infections, serotonin production is disrupted and systemic inflammation rises. Inflammatory molecules called cytokines cross the blood-brain barrier and directly impair the neurotransmitter systems that regulate mood. This “cytokine model of depression” is now one of the better-supported theories of why some people are completely unresponsive to antidepressants.
An often-overlooked companion issue is hypochlorhydria, chronically low stomach acid. Despite the cultural assumption that heartburn means too much acid, the opposite is frequently true. Low stomach acid impairs the absorption of iron, zinc, magnesium, B12, and fat-soluble vitamins, every nutrient discussed above. Someone can be taking all the right supplements and eating a healthy diet while absorbing very little of it, because the stomach environment needed to break down and extract those nutrients is compromised.
4. Genetic Variations Affecting Brain Chemistry
A landmark, genome-wide meta-analysis recently identified over 100 genetic variants associated with depression, emphasizing that variations in genes related to brain chemistry and function (particularly in prefrontal brain regions) significantly contribute to the risk of depression. Two genetic variants deserve particular attention in the mental health space.
The first is MTHFR, carried in some form by up to 60% of the population. MTHFR is an enzyme that converts folate into its active, usable form, which is essential for producing serotonin, dopamine, and norepinephrine. People with significant MTHFR variants often experience a baseline hum of anxiety, treatment-resistant depression, or OCD-like patterns, and may respond poorly to standard folic acid supplements (which require the impaired enzyme to be activated). Methylated B vitamin formulas are typically needed instead.
The second is COMT, which governs how quickly the brain clears stimulating neurotransmitters like dopamine and adrenaline. People with slow COMT, sometimes called the “worrier” variant, tend to have higher baseline levels of these chemicals, making them emotionally intense, highly sensitive, and prone to anxiety and overwhelm under stress.
Two other variants worth knowing about are pyrrole disorder (kryptopyrrole disorder), in which a metabolic byproduct causes chronic loss of both zinc and B6 in the urine, producing severe anxiety and stress intolerance; and porphyria, a less common but frequently missed condition in which impaired heme synthesis causes neurotoxic buildup that can look exactly like acute psychiatric illness.
5. Immune Dysfunction and Chronic Infection
Chronic infections, particularly tick-borne illnesses like Lyme disease and its co-infections (Bartonella is especially psychiatric in its presentation), reactivated viruses like Epstein-Barr, and mold illness from water-damaged buildings, generate persistent neuroinflammation that directly produces depression, anxiety, cognitive impairment, and personality changes. These are not “psychosomatic” responses to being ill; they are direct neurological effects of an immune system that cannot fully resolve the infection. Standard testing for these conditions is notoriously insensitive, and many people are told their labs are normal while continuing to suffer from an unresolved infectious or environmental trigger.
Also worth noting: in children, a sudden and dramatic behavioral change, OCD, tics, rage, separation anxiety, that appears to emerge overnight may be PANS or PANDAS, a condition in which an infection (often strep) triggers an autoimmune attack on the brain’s basal ganglia. These children are frequently misdiagnosed with primary psychiatric conditions for years. Hormonal and inflammatory factors also drive mood cycles: excessive prostaglandin production, often tied to omega-3 deficiency and magnesium insufficiency, can produce severe premenstrual anxiety and depression that are biochemically, not psychologically, driven.
6. Hormone Imbalances
The thyroid is one of the most commonly overlooked contributors to mood disorders, in both directions. Research has found that hypothyroidism (underactive) is one of the most common masqueraders of clinical depression, while hyperthyroidism (overactive) closely mimics panic disorder and generalized anxiety. Autoimmune thyroid disease (Hashimoto’s) can cause both, as antibody-driven inflammation produces unpredictable fluctuations. Crucially, a TSH test alone, the standard of care in conventional medicine, can completely miss clinically significant thyroid dysfunction. A full panel including free T3, free T4, reverse T3, and thyroid antibodies tells the complete picture.
Beyond the thyroid, low progesterone is a profoundly underappreciated driver of anxiety, insomnia, and emotional instability. Progesterone converts to allopregnanolone, a natural compound that acts on the same receptors as benzodiazepines, producing calming and sleep-promoting effects. When progesterone drops, whether from anovulatory cycles, perimenopause, or chronic stress diverting it toward cortisol production — this natural calming system collapses. Estrogen dominance (excess estrogen relative to progesterone), PCOS, and low testosterone in all genders round out a hormonal picture that has direct and significant consequences for mood, motivation, and cognitive function.
7. Metabolic and Blood Sugar Dysregulation
The brain has no glucose storage of its own and consumes 20% of the body’s energy supply. When blood sugar fluctuates, from high-glycemic eating, skipped meals, insulin resistance, or reactive hypoglycemia, the neurological consequences are immediate. A sharp drop in blood sugar triggers a surge of adrenaline and cortisol to rescue glucose levels, producing symptoms that are indistinguishable from anxiety: rapid heartbeat, trembling, irritability, and a sense of dread. Many people experience this cycle daily without ever connecting it to what they ate, or didn’t eat, two hours prior.
Insulin resistance, the metabolic state underlying pre-diabetes and metabolic syndrome, impairs dopamine signaling, generates systemic inflammation, and dysregulates the cortisol stress response. Chronically elevated cortisol from an overworked stress axis shrinks the hippocampus, drives blood sugar instability, and creates the characteristic pattern of exhaustion in the morning, crashes in the afternoon, and a wired inability to sleep at night. Addressing blood sugar regulation and the HPA (stress) axis is foundational to sustainable mood stability — and it is rarely part of a conventional mental health treatment plan.
8. Chronic Conditions with Psychiatric Overlap
Several chronic physical conditions carry a direct neurobiological burden on mood that goes far beyond a psychological reaction to being ill. Chronic Fatigue Syndrome (ME/CFS) is frequently misdiagnosed as depression, but the two are mechanistically different, and treating ME/CFS as a mood disorder while missing the underlying mitochondrial, immune, and autonomic dysfunction means patients never improve. Chronic pain conditions similarly alter the same brain circuits that regulate mood: the neurochemistry of persistent pain and the neurochemistry of depression overlap significantly, which is why pain that isn’t addressed becomes a powerful driver of apathy and hopelessness that no amount of therapy can fully resolve.
Sleep deserves special mention. Chronic insomnia is not just a symptom of mood disorders, it is one of their most potent causes. Sleep deprivation increases amygdala reactivity by up to 60%, impairs emotional processing, and prevents the brain from clearing the metabolic waste that accumulates during waking hours. Treating insomnia aggressively, and investigating its functional causes, from blood sugar instability to low progesterone to cortisol dysregulation, often produces more meaningful mood improvement than many other interventions.
So What Do You Do With This?
None of this is meant to suggest that therapy, medication, or psychological work isn’t valuable, it absolutely is. But for people who feel like they’ve done the work and still aren’t getting better, the body deserves a thorough investigation. The good news is that most of these factors are measurable, addressable, and respond well to targeted support.
If you’re a therapist, psilocybin facilitator, or someone who works closely with people in their mental health journey, consider adding a few key questions to your intake process:
- When did you last have comprehensive bloodwork, not just a standard panel?
- Do your symptoms follow a pattern related to your cycle, your diet, or the seasons?
- Have you ever had a prolonged illness, tick exposure, or lived or worked in a building with water damage?
- Do you feel significantly better or worse in particular environments?
These questions open doors that conventional intake forms don’t. And behind some of those doors is the physiological root that, once addressed, finally allows the psychological work to land.
The body and the mind are not separate systems. When the body is struggling, the mind will reflect it, no matter how good the therapy.
Have questions about whether a functional workup might be right for you? Reach out to us at Empathy Grove to schedule a consultation. By Kara Crisp, ND, Licensed Naturopathic Physician
