Advanced Diagnostic Testing
Additional testing can add information beyond a standard panel when it is clinically relevant. Some of these tests are validated and some are investigational, and Dr. Lewis explains the difference.
Comprehensive Nutritional Analysis
Identifies subtle vitamin, mineral, antioxidant, and fatty-acid deficiencies that can affect mood, cognition, and energy.
Detailed Hormone Mapping
Measures thyroid function, adrenal health, sex hormones, and hormone metabolites to reveal patterns influencing mood, stress, and metabolism.
Microbiome Assessment
Looks at the makeup of your gut bacteria and markers of digestion. Research linking specific results to mood is still early, so findings are read alongside your overall health picture.
Food Sensitivity Testing
Food reactions are best identified with a supervised elimination and reintroduction. IgG food panels mostly reflect normal immune exposure, and allergy specialists advise against using them to diagnose food intolerance.
Toxin and Exposure Screening
Checks for heavy-metal or environmental exposure when your history suggests it. Urine mycotoxin and provoked “toxic metal” tests are not validated for psychiatric diagnosis and are optional, not a standard workup.
Genetic Insight Analysis
Highlights genetic variations that may affect nutrient needs, detox pathways, and mental-health resilience. This guides targeted support rather than predicting disease.
Some functional tests are not validated for diagnosis; Dr. Lewis explains what each can and cannot tell you, and results are always read alongside your history and symptoms.
Therapeutic Nutrition
Nutrition may play an important role in supporting brain and nervous-system function. We help you understand which dietary patterns may support or worsen symptoms, and how to use nutrition as a powerful therapeutic tool.
Personalized Dietary Planning
Structured around your labs, symptoms, and goals—not generic dietary advice.
Anti-Inflammatory Protocols
Reduce inflammation by removing triggers and adding foods that soothe the immune system.
Gut Healing Programs
Support a healthy microbiome and digestive health through strategic food choices.
Metabolic Reset Plans
Improve insulin sensitivity, stabilize blood sugar, and support energy production.
Nutrient Repletion Strategies
Use food and targeted supplements to restore missing nutrients.
Elimination & Reintroduction Protocols
Identify food triggers through a clear, guided process.
Therapeutic Meal Timing
Align eating patterns with circadian rhythms to support hormones, metabolism, and cellular repair.
Targeted Supplementation
Supplements are used with intention—not as a long list of products, but as precise tools chosen to support your biology.
Evidence-Based Formulas
Selected for quality, potency, and clinical effectiveness.
Targeted Nutrients & Botanicals
Chosen based on your lab findings and symptoms to correct specific imbalances.
Professional-Grade Quality
Free from fillers, contaminants, and low-quality ingredients that can hinder progress.
Strategic Timing
Dosed and scheduled to maximize absorption and therapeutic impact.
Ongoing Adjustments
Updated as your health improves, ensuring you take only what you need.
Cost-Conscious Planning
Prioritizes supplements with the highest impact so your protocol remains affordable.
Supplements help fill the gaps while your body works toward long-term balance.
Lifestyle Medicine
Daily habits shape long-term health. We help you build simple, sustainable routines that support healing.
Personalized Movement Plans
Gentle, structured activity matched to your energy and physical capacity.
Sleep Optimization
Improves circadian rhythms, sleep quality, and nighttime repair processes.
Stress Response Training
Practical mind-body tools to calm the nervous system and reduce inflammation.
Environmental Detoxification
Simple changes at home and work to reduce toxin exposure.
Mind-Body Practices
Evidence-based strategies like meditation, breathwork, and grounding.
Social Connection Support
Strengthen healthy relationships and reduce isolation.
Nature Engagement
Use time outdoors to improve mood, immunity, and stress resilience.
Lifestyle medicine turns everyday routines into therapeutic tools.
Cognitive-Behavioral Support
Your mindset and emotional patterns shape your physical health more than most people realize.
Reshaping Limiting Health Beliefs
Helps identify beliefs that undermine healing and replace them with supportive frameworks.
Health-Promoting Mindsets
Builds psychological resilience and confidence in your ability to influence your health.
Behavior Change Tools
Uses science-backed strategies for forming sustainable habits.
Emotional Processing
Addresses emotional stressors that may contribute to physical symptoms or slow recovery.
Health Self-Efficacy Development
Strengthens your sense of agency and ability to navigate setbacks.
Navigate Healthcare Effectively
Supports informed decision-making, self-advocacy, and coordinated care.
Healing Narrative Creation
Reframes your health story to support recovery and reduce fear-based thinking.
This work supports the mind-body connection so your emotional health aligns with your physical healing.
The functional medicine library. Everything above describes the approach; the pages below are the work itself, grouped by what is being looked at. None of it is a protocol to follow on your own — which of these questions is worth asking about you is what an assessment is for.
What functional psychiatry is
- Functional Psychiatry: A Root-Cause Mental Health Guide — This guide explains what functional psychiatry is, how it factors in biology and lifestyle, and what a first visit with Dr. Lewis involves.
- What Is Functional Psychiatry? — Learn what functional psychiatry is, how it differs from conventional psychiatry, and its foundational pillars like gut health and inflammation.
- Root-Cause Mental Health Treatment Explained — Learn what root-cause treatment means, why symptom-only care falls short, and how functional psychiatry addresses inflammation, nutrition, and genetics.
- Functional vs. Traditional Psychiatry: Which Is for You? — Explore the key differences between functional and traditional psychiatry, from their philosophy and evaluation to their treatment plans.
Further reading
- Root Cause Psychiatry: Go Beyond Symptom Management
- Functional Medicine Psychiatry in Brooklyn
- Hidden Root Causes of Anxiety, Depression, and Fatigue
- 12 Root Causes of Depression Antidepressants Can't Fix
- Root Causes of Depression: A Functional Medicine Approach
- Functional Psychiatrist in NYC
- Functional Psychiatry in Brooklyn, NY
Functional care by presentation
- Functional Psychiatry for Anxiety Treatment in NYC — Dr. Beata Lewis treats anxiety through functional psychiatry in NYC, addressing root causes like gut health, hormones, and nutrition alongside therapy.
- Functional Medicine for Depression and Anxiety — Discover how functional medicine uncovers the root causes of depression and anxiety—through lab testing, gut health, hormones, and personalized care.
- Functional ADHD Treatment in NYC — Dr. Bliss Lewis offers functional psychiatry for ADHD in NYC, addressing root causes with nutrition, lifestyle, and integrative testing.
- The Functional Medicine Approach to ADHD Evaluation — Standard ADHD evaluations stop at diagnosis. An integrative psychiatrist explains testing that uncovers root-cause metabolic and hormonal factors.
Further reading
- Natural ADHD Remedies for Adults: A Functional Guide
- CBT and Functional Psychiatry Combined in Brooklyn
- 90-Day Functional Medicine Plan to Heal Gut, Heart, and Mind
Testing, and what it can and cannot tell you
- Comprehensive Lab Testing for Mental Health — Get advanced lab testing for functional medicine and mental health diagnostics. Dr. Beata Lewis, MD gets to the root of the problem.
- Advanced Lab Testing for Mental Health — Advanced lab testing to uncover root causes of mental health issues. Identify imbalances and get psychiatric care for optimal well-being.
- Functional Medicine Lab Tests for Mental Health — Learn which functional medicine lab tests can uncover root causes behind mental health symptoms, from thyroid panels to nutrient and metabolic markers.
- Functional Testing: What's Worth Measuring, and Why — A psychiatrist's guide to which functional lab tests actually change treatment decisions, and which ones are not worth ordering.
Further reading
- 7 Lab Tests Your Psychiatrist Should Order
- How Lab Testing Personalizes Mental Health Care
- Lab Testing in Integrative Psychiatry
- Functional Medicine Testing: Gut, Mood, and Heart Health
- Unlock Mental Health Clues with Organic Acid Testing
- Unlocking Mental Health with a Gut Health Test
- Gut Microbiome Testing for Depression & Mental Health
- Heal the Gut-Brain Axis: Sarah’s Recovery Roadmap
The gut-brain axis
- Gut Health & Mental Wellness — Discover the connection between gut and mental health with integrative medicine. Dr. Beata Lewis, MD, offers holistic care in Brooklyn.
- The Gut-Brain Axis & Mental Health — Learn how the gut-brain axis affects mood, focus, and mental health. Discover how restoring gut balance can support anxiety, depression, and clarity.
- Healing Your Brain by Healing Your Gut — Beata Lewis MD — With nutrition, there's good and bad news. The bad: changes in the Standard American Diet have increased chronic diseases and mental health issues.
- Gut-Brain Connection: Your Microbiome's Mental Health — Discover how the gut-brain connection works and why your microbiome's health is crucial for your mental well-being.
Further reading
- 7 Signs Your Anxiety Is Actually a Gut Problem
- ADHD and the Gut-Brain Connection
- The Gut-Brain Connection in ADHD Explained
- Gut-Brain-Weight Connection: Microbiome and Mood
- The Gut-Heart-Mind Connection: Mood and Heart Health
- Short Chain Fatty Acid Benefits for Mental Health
- Tryptophan and Gut Health: Pathways to Mental Wellness
- GABA Bacteria: How Lactobacillus Supports Mental Health
- GABA Bacteria and Natural Ways to Boost and Calm the Mind
Leaky gut, SIBO and dysbiosis
- 10 Signs of Leaky Gut and Mental Health Symptoms — Discover how leaky gut may contribute to anxiety, depression, brain fog, fatigue, food sensitivities, and inflammation through the gut-brain connection.
- Leaky Gut and Depression: What You Need to Know — Discover how symptoms of leaky gut may contribute to depression and learn proven steps to heal your gut and support your mood.
- SIBO and Mental Health: Depression, Anxiety & Brain Fog — Learn how SIBO may contribute to depression, anxiety, brain fog, and fatigue through the gut-brain axis, plus evidence-based treatment approaches.
- Dysbiosis and Depression: The Gut-Brain Connection — Explore how gut dysbiosis, an imbalance in gut bacteria, may contribute to depression through the gut-brain connection and inflammation.
Further reading
- Leaky Gut, Depression & the Gut-Brain Link: An Inside Look
- Leaky Gut, Nutrition & Mental Health Explained (SHORT)
Probiotics and the microbiome
- 8 Probiotic Strains That Support Mental Health — Learn which probiotic strains have the strongest evidence for supporting anxiety, depression, stress resilience, sleep, and overall gut-brain health.
- Probiotics for Depression: What the Science Reveals — Discover how probiotics may ease depression symptoms, support gut health, and enhance mental wellness as part of integrative care.
- The Gut-Brain Connection: Probiotics & Mental Health — Discover the gut-brain connection and how probiotics, diet, and microbiome health can support your mental health alongside antidepressant treatment.
- Psychobiotics: Probiotics That Boost Mental Health — Discover how psychobiotics—research-backed probiotics—can naturally ease anxiety and improve mood with minimal side effects.
Further reading
- How to Choose and Use Probiotics for Gut Health
- How to Use Probiotics for Mental Health
- 4 Ways Probiotics Can Improve Your Mental Health
- Probiotics for Depression — Beata Lewis MD
- Picking Personalized Probiotics for Fostering Gut Health
- Effective Probiotic Therapy for Depression Treatment
- Advanced Microbiome Strategies for Resistant Depression
- Advanced Microbiome Care for Resistant Depression
Inflammation and mood
- Inflammation and Mental Illness — Beata Lewis MD — A cut turns red, swollen, and hot due to acute inflammation—your body’s way of healing and fighting infection. It’s helpful and fades once healing’s done.
- Inflammation and Depression: What We Know So Far — Depression has a measurable body component for many people. Learn what inflammation-depression research actually shows, and what remains uncertain.
- 9 Anti-Inflammatory Foods for Depression Relief — Discover anti-inflammatory foods that may help support depression recovery, reduce neuroinflammation, and promote better brain and gut health naturally.
- 10 Ways to Reduce Chronic Inflammation — Ten practical, evidence-based strategies to calm chronic inflammation through diet, sleep, stress, and gut health, from an integrative psychiatry practice.
Further reading
- Inflammation and Depression: The Hidden Link
- Inflammation and Depression
- Inflammation and Mood: The Gut–Brain Connection
- Inflammation and ADHD: The Hidden Connection
- Inflammation and Bipolar Disorder: New Frontier?
- The Link Between Inflammation and Schizophrenia
- How Inflammation Links Depression and Heart Disease
- How Obesity-Related Inflammation Impacts Brain and Mood
- Inflammation and Child Mental Health
Nutrients and deficiencies
- Nutrient Deficiencies That Affect Your Mental Health — Learn which nutrient deficiencies are linked to mood issues and how to support your brain and mood naturally with food and lifestyle steps.
- 9 Nutrient Deficiencies Linked to Anxiety — Learn which nutrient deficiencies may contribute to anxiety, how they affect brain function, and which lab tests can identify imbalances.
- Depression and Vitamin B12 Deficiency: The Link — Learn about the link between depression and vitamin B12 deficiency, including symptoms, causes, and treatment options to improve mental health.
Further reading
- Vitamin B12's Role in Depression and Mind-Body Health
- How to Identify and Treat B12 Deficiency — Beata Lewis MD
- B12 Deficiency Treatment for Depression
- Vitamin B12 Deficiency: Treatment and Prevention Guide
- Vitamins for Depressed Children
- Vitamins and Depression in Children — Beata Lewis MD
Vitamin D
- Vitamin D and Mental Health: What Research Shows — Separating evidence from hype: what research actually shows about vitamin D, depression, anxiety, and brain health.
- A Practical Guide to Vitamin D: Food, Sunlight, Supplements — How to increase vitamin D through food, sunlight, and supplements. Practical advice on vitamin D sources, absorption, and choosing the right supplement.
- Should You Test Your Vitamin D Levels? — When should you test vitamin D for mental health? A psychiatrist explains who benefits from testing and how to interpret results.
- Vitamin D Dosing for Mental Health: Levels & Dosage Guide — Learn the optimal vitamin D dosage for mental health, ideal blood levels, how long to supplement, and what research says about mood and depression.
Further reading
- How Vitamin D Affects Your Brain
- Can Vitamin D Help Anxiety? An Honest Look at the Evidence
- Vitamin D and Antidepressants: Does It Help?
- Vitamin D for Depression: Boost Mood Naturally
- Vitamin D Deficiency and Depression: 31 Clinical Trials
- Who Benefits Most from Vitamin D for Mental Health?
- Everything You Need to Know About Vitamin D
- Vitamin D and Child Mental Health — Beata Lewis MD
- Vitamin D, Pregnancy, and Brain Development
- Vitamin D's Role in Psychosis and Schizophrenia
Hormones, thyroid and perimenopause
- Thyroid, Cortisol & ADHD: Hormonal Mimics Explained — Learn how thyroid dysfunction and cortisol imbalances can mimic or worsen ADHD symptoms. Discover when hormone testing may help clarify the diagnosis.
- ADHD and Hormones: Menstrual Cycle to Perimenopause — How estrogen and progesterone affect ADHD symptoms and medication effectiveness across the cycle and perimenopause.
- Perimenopause Hormones and Sleep Problems Explained — Learn how estrogen, progesterone, and FSH changes during perimenopause affect sleep, insomnia, and nighttime awakenings.
Further reading
- Progesterone, GABA, and ADHD: The Neurosteroid Link
- Perimenopausal Sleep: The Bigger Picture
- The Integrative Toolkit for Perimenopausal Sleep
- Gut Health, Inflammation, and Sleep in Perimenopause
- Non-Hormonal Sleep Medications for Perimenopause
Fasting and metabolic resets
- Extended Fasting and Gut Health: Improve Your Mood — Learn how extended fasting helps reset your gut microbiome, reduce inflammation, and improve mental health through autophagy and microbial balance.
- Reset Your Microbiome with Extended Fasting — Discover how extended fasting can rebalance your microbiome, improve mood, and enhance mental clarity by resetting gut-brain communication.
- Fasting, Inflammation, and Mental Health — Learn the bridge between chronic inflammation mental health. Learn how reducing inflammation can improve mood, clarity, and emotional resilience.
Further reading
The information provided on this website is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.