Understanding Elevated Serotonin & Dopamine
Neurotransmitters like serotonin and dopamine are critical for mood, behavior, and physiological balance. While deficiencies get a lot of attention, excess levels can also cause significant symptoms—and may point to underlying health issues that need to bead dressed.
When Serotonin Runs High
Possible Symptoms
- Anxiety, agitation
- Diarrhea
- Altered mental status
- Hyperreflexia (overactive reflexes)
- Autonomic instability (e.g., abnormal heart rate, blood pressure swings)
In severe cases—especially with sudden onset—consider serotonin syndrome, a potentially life-threatening condition.
Associated Conditions
- Schizophrenia
- Autism spectrum disorders
Potential Causes
- Supplements: melatonin, tryptophan, 5-HTP
- Medications (especially in combination): antidepressants, trazodone, triptans, dextromethorphan, opioids, antiemetics, lithium, linezolid, ritonavir
- Recent illicit drug use
- Diet & lifestyle: low-protein/high-carb meals, high insulin levels, exercise, and bright light exposure can all boost serotonin
- Enzyme deficiency: decreased monoamine oxidase (MAO) activity
- Gut dysbiosis: overgrowth of Clostridia, Staphylococcus, Bifidobacterium, and Enterococcus can produce excess serotonin
When Dopamine Is Elevated
Possible Symptoms
- Worry, distrust, social withdrawal
- Hyperfocus or impulsivity (seen in ADHD, OCD)
- Heightened drive or agitation (acute stress, manic states)
- Anticipation-related behaviors (gambling, addiction)
Associated Conditions
- Schizophrenia
- Pregnancy-related mood changes
- Rare in children: neuroblastoma, Costello syndrome, leukemia, pheochromocytoma, Menke’s disease, rhabdomyosarcoma of the bladder
- Rare in adults: carcinoid tumor, pheochromocytoma
Potential Causes
- Supplements: phenylalanine, tyrosine, Mucuna pruriens
- Medications: NDRIs, SNRIs, Parkinson’s drugs (dopamine agonists), MAOIs
- Recent illicit drug use
- Enzyme deficiency: low catechol-O-methyltransferase (COMT) and/or MAO activity
- Gut dysbiosis: overgrowth of Staphylococcus, Bacillus, Proteus, Serratia, Escherichia, or Clostridia (which can slow dopamine-to-norepinephrine conversion)
Enzyme Function & Hormonal Influence
A Comprehensive Neuro transmitter Profile can help determine if slow breakdown of serotonin/dopamine is due to reduced COMT or MAO activity.
- Lower testosterone and/or estrogen dominance commonly reduce both enzyme activities.
Factors That Decrease MAO Function
- Tobacco
- Caffeine
- Nutrient deficiencies: iron, vitamin B2, vitamin B3
- Herbs: bilberry, curcumin, echinacea, evening primrose, licorice, rhodiola, St. John’s wort
Factors That Reduce COMT Function
- Chronic stress, oxidative stress, environmental toxins (metals, plastics)
- Multiple medications
- Poor diet (processed foods, high sugar, artificial sweeteners)
- Leptin/insulin resistance
- Nutrient deficiencies: magnesium, methylfolate (MTHF), methyl cobalamin, methionine
- Genetic variants: COMT or MTHFR polymorphisms
Supporting COMT & MAO Enzymes
COMT Support
- SAMe: 100–500 mg
- Magnesium: 150–500 mg
- MTHF: 400–5000 mcg
- Methyl cobalamin: 1000–5000 mcg
- Foods/herbs: cruciferous vegetables, soy (genistein), resveratrol, citrus, rooibos, dandelion, rosemary, curcumin
MAO Support
- Vitamin B2 (riboflavin-5-phosphate preferred): 50 mg
- Vitamin B3: 100 mg
- Iron (if deficient via serum testing): 25–50 mg
Additional Testing to Consider
- Hormone panel: Salivary estradiol, progesterone, testosterone, diurnal cortisol
- Genetic testing: SNPs (COMT, MTHFR) and methylation status
- GI360: Especially with digestive symptoms, poor diet, or poor treatment response
- Specific tumor testing:
- Pheochromocytoma: episodic headache, sweating, tachycardia, hypertension → test via 24-hour urinary fractionated catecholamines/metanephrines (low suspicion) or plasma fractionated metanephrines (high suspicion)
- Carcinoid tumor: chronic flushing/diarrhea → test via 24-hour urine 5-HIAA
Clinical Perspective
- Mild elevations of serotonin or dopamine without alarming symptoms are usually not cause for panic.
- First steps: review medications/supplements, assess diet, digestion, stress.
- Next: order targeted testing (hormone profile, microbiome mapping, genetic analysis) to uncover the root cause.
Bottom line: Rather than treating neurotransmitter levels in isolation, identify and address the upstream factors—hormonal imbalances, enzyme activity, gut health, and lifestyle—to restore natural balance.
