The Dr. Hyman Show

For decades, depression has often been described as the result of a chemical imbalance in the brain. But how strong is the evidence behind that idea? This episode explores one perspective on an area of medicine that continues to be actively debated and is intended to encourage thoughtful discussion—not to provide individualized medical advice.

Today on The Dr. Hyman Show, I'm joined by psychiatrist and researcher Dr. Joanna Moncrieff to examine the science behind the serotonin theory and explore how it shaped modern mental health care. Together, we consider why rethinking our assumptions may open the door to a more complete understanding of depression and recovery.

We discuss:

• Whether depression is best understood through the lens of a chemical imbalance—or something far more complex

• How the serotonin theory shaped modern psychiatry and why it's increasingly being questioned

• What current research says about antidepressants, emotional numbing, and informed consent

• Why lifestyle, nutrition, trauma, and social connection deserve a larger role in supporting mental health

• How a more individualized, whole-person approach could change the way we think about depression and recovery

Mental health treatment is deeply personal, and this episode explores one perspective on an area of medicine that continues to evolve. If you're currently taking antidepressants or other prescription medications, don't stop or change your treatment based on this discussion alone. Instead, use it as a starting point for an informed conversation with your healthcare provider.

Learn More: Dr. Moncrieff recently participated in an FDA Expert Panel on SSRIs and Pregnancy. If you'd like to explore another perspective on the evidence discussed in this episode, you can watch the panel here.

View Show Notes From This Episode

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(0:00) The impact of the chemical imbalance theory and myths of mental illness

(2:02) Disclaimers and introduction of Joanna Moncrieff

(3:00) The serotonin myth, antidepressant use, and marketing of SSRIs

(16:12) Risks, side effects, and wrong-headed approaches to mental health

(21:00) Societal, biological, and lifestyle factors in mental health

(27:13) Commercial determinants of health

(30:49) The rise and implications of psychedelic treatments in psychiatry

(43:21) Drug-centered vs. disease-centered models in mental health

(45:40) The role of the brain and alternative approaches to treating depression

(50:00) Addressing severe depression and strategies for deprescribing antidepressants

(54:41) Reframing mental health narratives and future outlook

(57:09) Encouraging self-education, debate, and discussion in medicine

(59:23) Closing remarks, disclaimers, and gratitude to sponsors

Do you hit a wall every afternoon around 2 or 3 p.m.? If your energy disappears, your brain gets foggy, and you need caffeine or sugar just to finish the day, it isn't a lack of willpower—it's a sign that something deeper is driving your energy crash. In this episode, I explain the three biggest drivers of the afternoon slump and the simple changes that can help you maintain steady energy all day long.

In today's episode, I discuss:

The three hidden causes of the afternoon energy crash

Why skipping breakfast, relying on coffee, sugary smoothies, or carb-heavy meals sets you up for an inevitable drop in energy later in the day

How to build meals with protein, healthy fats, and fiber to stabilize blood sugar and create lasting energy instead of quick spikes and crashes

Simple daily habits that can dramatically improve your energy and focus

That afternoon crash isn't something you have to accept as part of modern life. When you stabilize your blood sugar, support your body's natural rhythms, and reduce chronic stress, your energy becomes more consistent, your focus improves, and you stop relying on caffeine and willpower just to make it through the day.

Resources Mentioned:

Track your metabolic health with Function Health: https://functionhealth.com/mark (Use code MARK2026 for $50 off your membership.)

Have a question you’d love answered on Office Hours? Submit it here

(0:00) Understanding the afternoon crash and blood sugar's role in energy

(4:36) Importance of circadian rhythm

(8:06) Environmental toxins and health

(9:36) Impact of stress on energy and caffeine use

(12:55) Rapid fire Q&A

(15:08) Key takeaways for steady energy

We all experience stress. The real challenge isn't stress itself—it's whether we recover from it. Over time, chronic stress can quietly affect everything from inflammation and metabolism to sleep, digestion, and healthy aging.

This week on The Dr. Hyman Show, I talk with nervous system educator and HRV expert Salim Najjar to explore what heart rate variability (HRV) can reveal about your body's ability to recover from stress and build resilience.

Together, we unpack:

• How to use HRV to better understand your body's response to stress

• Why some stress makes you stronger while chronic stress wears you down

• How to get more value from your wearable without obsessing over the numbers

• Five daily habits that can help your nervous system recover and become more resilient

• How your nervous system influences inflammation, healing, and healthy aging

Our bodies are constantly responding to the demands we place on them every day. The good news is that resilience can be built, and the strategies in this conversation can help you recover from stress more effectively and support long-term health. To help you get started, Salim has created a free HRV guide that includes a personalized quiz and AI coach exclusively for listeners.

View Show Notes From This Episode

Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health

https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link

Get Free Weekly Health Tips from Dr. Hyman

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Sign Up for Dr. Hyman’s Weekly Longevity Journal

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Join the 10-Day Detox to Reset Your Health

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Join the Hyman Hive for Expert Support and Real Results

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This episode is brought to you by Perfect Amino, Cozy Earth, Timeline, Sunlighten, Made In, and Seatopia.

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(0:00) Introduction to HRV

(3:43) Introduction to Salim and his HRV expertise

(4:18) What is HRV and how is it measured

(5:32) Chronic stress, stress regulation, and sovereignty

(9:52) Why HRV is an important health metric

(20:31) Deeper dive into HRV as a health indicator

(25:43) Salim's HRV coaching, website, and personal journey

(28:49) Salim’s framework and steps for improving HRV

(30:07) The role of sleep and hormetic stress in HRV

(33:12) Tools and tracking for HRV measurement

(37:22) The art framework and five pathways for HRV

(38:17) Salim’s injury, reframing, and HRV improvement

(46:22) Viktor Frankl, intentionality, and alignment

(51:46) Community and its role in health and HRV

(55:02) Practical steps for building community and emotional regulation

(58:18) Emotional processing, elite athletes, and HRV performance

(1:00:35) Sovereignty, compassion, and daily nervous system practices

(1:03:18) Awareness, parasympathetic activation, and reframing HRV

(1:05:01) Closing remarks, social media, and gratitude

(1:05:51) Disclaimer and sponsor acknowledgments

Histamine isn't just about seasonal allergies or a runny nose. It influences your brain, gut, hormones, immune system, and nervous system—and when your body can't regulate it properly, it can show up as everything from anxiety and migraines to insomnia, digestive issues, skin rashes, and brain fog. In this episode, I explain why histamine overload happens, how it relates to Mast Cell Activation Syndrome (MCAS), and what a root-cause approach looks like for calming an overactive immune system.

In today's episode, I discuss:

* Why MCAS and histamine intolerance are different—and how overactive mast cells can drive symptoms ranging from migraines and anxiety to digestive issues, hives, and heart palpitations
* The hidden triggers behind mast cell activation, including gut dysfunction, chronic infections, mold exposure, hormone imbalances, stress, and environmental toxins
* Why many "healthy" foods like avocados, spinach, tomatoes, kombucha, and bone broth can temporarily worsen symptoms when your histamine bucket is already full
* A root-cause approach to calming the immune system using nutrition, targeted supplements, medications when needed, nervous system regulation, and addressing the underlying drivers of inflammation

MCAS isn't simply a histamine problem—it's a sign that your immune system has become dysregulated. Instead of just suppressing symptoms, the goal is to understand why your mast cells are overreacting in the first place. When you lower the overall inflammatory load and restore balance to the gut, immune system, hormones, and nervous system, you create the conditions for lasting healing rather than temporary symptom relief.

Resources Mentioned:

* Track your biomarkers with Function Health: https://functionhealth.com/mark (Use code MARK2026 for $50 off your membership.)
* Have a question you’d love answered on Office Hours? Submit it here

For decades, we've thought about conditions like Alzheimer's disease, depression, and Parkinson's disease as disorders of the brain. But what if that's only part of the story?

Emerging science is revealing that many of the factors driving cognitive decline, mental illness, and neurodegenerative disease may begin far outside the brain itself—in our metabolism, our immune system, our gut microbiome, our hormones, and even the environment we're exposed to every day.

As part of our summer series, we're revisiting some of the most important conversations we've had on the topic of brain health.

In this special compilation episode, you'll hear from leading experts Dr. Richard Isaacson, Dr. Chris Palmer, and Drs. Ray Dorsey and Michael Okun as they explore the new science of brain health and what it means for preventing cognitive decline, supporting mental health, and protecting our brains as we age.

What I find most encouraging about this research is that it challenges the idea that brain decline is simply an inevitable part of aging. Instead, it suggests that many of the biggest drivers of brain health are things we can influence through the choices we make, the environments we create, and the ways we care for our bodies long before symptoms ever appear.

View Show Notes From This Episode

Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health

https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link

Get Free Weekly Health Tips from Dr. Hyman

https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast

Sign Up for Dr. Hyman’s Weekly Longevity Journal

https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast

Join the 10-Day Detox to Reset Your Health

https://drhyman.com/pages/10-day-detox

Join the Hyman Hive for Expert Support and Real Results

https://drhyman.com/pages/hyman-hive

This episode is brought to you by Timeline, Sunlighten, Seed, BIOptimzers, Paleovalley, and Pique.

Support healthy aging and get 20% off at timeline.com/drhyman with code HYMAN.

Discover why so many people are using sunlighten.com and save up to $2,100 today and free shipping with code HYMAN.

Make your microbiome part of your daily routine with seed.com/hyman and save 25% with code 25HYMAN.

Go to bioptimizers.com/hyman and use code HYMAN to save 15% off your order, plus get a free gift. 

Shop nutrient-rich foods and supplements at paleovalley.com/hyman and save 15% off your first order.

Elevate your daily wellness ritual at piquelife.com/hyman and enjoy 15% off for life plus free gift

(0:00) Understanding brain dysfunction, inflammation, and lifestyle interventions

(0:21) Heavy metals, toxins, and Parkinson's disease

(3:30) Introduction to the summer series on brain health

(4:02) The MIND diet, precision nutrition, and brain-healthy fats

(9:06) Vitamins, supplements, and caloric intake for cognitive health

(11:23) Vitamin D, B complex, and reversing mild cognitive impairment

(14:05) Additional supplements and intensive lifestyle interventions

(17:18) Importance of magnesium and metabolic health

(18:24) Multimodal treatments, hormone replacement therapy, and individualized care

(26:49) Biopsychosocial factors, stress, and the gut-brain connection

(32:30) Inflammation, energy dysregulation, and metabolism in brain health

(42:33) Parkinson's disease: causes, history, and environmental factors

(46:02) Leaky brain, blood-brain barrier, and Parkinson's as a whole-body disease

(49:00) Closing remarks, disclaimer, and gratitude to sponsors