Serotonin Isn’t the Hero You Think It Is – Here’s Why

 

For decades, serotonin has been celebrated as the “feel-good” molecule, praised as the key to managing anxiety, OCD, and sensory sensitivities. Treatments like SSRIs (selective serotonin reuptake inhibitors, a class of medications designed to increase serotonin levels in the brain), tryptophan supplements, and serotonin-rich diets have been built on this understanding, offering what feels like a straightforward solution to complex challenges. But what if serotonin isn’t always the calming hero we’ve been told it is? What if, for some children, serotonin acts as a stress signal, amplifying the very behaviours and emotions it is supposed to ease?

This question is not only thought-provoking but also deeply relevant to the children we see every day at Brainstorm Health Clinics. Years of clinical experience, coupled with groundbreaking research by Jim Adams and the paradigm-shifting insights of Ray Peat, have led us to re-examine serotonin and its role in complex behaviours. Through detailed testing, including organic acids, stool analysis, thyroid panels, and micronutrient assessments, we have discovered that serotonin imbalances often point to deeper systemic issues. Understanding this opens the door to more personalised and effective approaches.

Let us explore why serotonin-boosting treatments sometimes work beautifully, why they can backfire, and how this new understanding allows us to address serotonin dysfunction with greater precision.

 

Serotonin’s Dual Nature: Why Treatments Can Help or Harm

Serotonin is often described as a calming neurotransmitter. For children with genuinely low serotonin levels, boosting serotonin can stabilise mood, reduce anxiety, and ease compulsive behaviours. SSRIs prevent serotonin from being reabsorbed too quickly, keeping it active in the brain for longer. Supplements like tryptophan and 5-HTP provide the building blocks needed to produce serotonin, which can be especially helpful if the body is struggling to synthesise it due to nutrient deficiencies, chronic stress, or metabolic dysfunction.

Imagine serotonin as the conductor of a grand neurotransmitter orchestra, tasked with keeping the brain’s intricate chemical symphony in tune. When serotonin levels are artificially boosted through SSRIs like fluoxetine, sertraline, or citalopram, they can quiet the relentless noise of intrusive thoughts or sensory overload. For many, this brings a sense of relief. However, some describe feeling emotionally flat, as if the melody of their emotions has been dialled down. This phenomenon, often called emotional blunting, highlights the delicate balance serotonin maintains.

Elevating serotonin too much can deplete other key neurotransmitters. Dopamine, for instance, fuels motivation, pleasure, and the sense of reward. When dopamine levels drop, the effects can extend beyond appetite, affecting energy, focus, and the ability to feel satisfaction from achievements. Norepinephrine, essential for alertness and energy, may also be reduced, along with GABA, the neurotransmitter that promotes calm. These changes ripple through mood, stress regulation, and even hunger signals, underscoring just how interconnected this chemical orchestra is.

 

Children with low serotonin often exhibit a specific set of symptoms:

Persistent sadness or low mood

Anxiety or chronic worry

Difficulty falling or staying asleep

Fatigue despite adequate rest

Cravings for carbohydrate-heavy foods

A tendency to overthink or ruminate

For these children, serotonin-boosting treatments can be transformative, at least in the short term. However, they do not address the underlying drivers of low serotonin, such as systemic inflammation, gut dysbiosis, or thyroid dysfunction. This can create a false sense of resolution, where symptoms improve temporarily but the root causes remain unaddressed.

For other children, boosting serotonin has the opposite effect. Instead of calming, serotonin can act as a stress signal, heightening sensory sensitivities, amplifying compulsive behaviours, and increasing emotional outbursts. Elevated or dysregulated serotonin often fuels neuroinflammation and intensifies sensory and emotional challenges.

 

Children with high or dysregulated serotonin may display a very different set of symptoms:

Sensory hypersensitivities, such as extreme reactions to light, sound, or textures

Aggression, irritability, or frequent emotional outbursts

Compulsive behaviours that worsen with serotonin-boosting treatments

Restlessness or agitation, particularly after starting SSRIs or 5-HTP

Fatigue paired with heightened sensory processing issues

This dual nature of serotonin means it can either be part of the solution or part of the problem, depending on the child’s unique biochemical and systemic landscape.

 

Exploring Serotonin as a Stress Signal

Ray Peat, a biologist and physiologist, has been instrumental in reframing serotonin as more of a stress marker than a universal calming neurotransmitter. He argues that serotonin often rises as a compensatory mechanism when the body is under stress. This perspective aligns with what we see in children whose bodies are struggling with chronic energy deficits, systemic inflammation, or mitochondrial dysfunction.

When the body cannot produce energy efficiently, serotonin levels rise to help it adapt. While this may provide short-term survival benefits, it can also lead to neuroinflammation and sensory overload. Lights seem brighter, sounds sharper, and textures more overwhelming. Instead of soothing the nervous system, serotonin exacerbates sensory and emotional sensitivities.

The gut is a serotonin factory, producing around 95 percent of the body’s supply to regulate digestion. But when gut health falters due to inflammation or dysbiosis, the effects can ripple throughout the body. A damaged gut barrier can allow inflammatory molecules and toxins to enter the bloodstream, sparking systemic inflammation.

While serotonin itself cannot cross the blood-brain barrier, its precursor, tryptophan, can. Once in the brain, tryptophan is converted into serotonin, a process influenced by diet, inflammation, and gut health. Inflammatory signals from the gut can also disrupt brain function, contributing to neuroinflammation and amplifying sensory and behavioural challenges. It is a powerful reminder of how intimately connected the gut and brain are.

 

Artificially Raising Serotonin and Its Impact on Hormonal Development

Serotonin plays a powerful role in regulating the body’s hormonal systems, particularly the production of testosterone and oestrogen. During adolescence and young adulthood, when these hormones are pivotal for growth, emotional well-being, and sexual development, artificially raising serotonin levels can have unintended and at times worrying consequences. Studies reveal that up to 70% of adults on SSRIs report sexual dysfunction, such as reduced libido. For younger individuals, the stakes are even higher, with evidence suggesting that serotonin manipulation can delay sexual maturation and disrupt critical hormonal processes.

This happens because serotonin interacts with the hypothalamus and pituitary gland, which serve as the body’s hormonal command centres. Elevated serotonin can alter the release of gonadotropin-releasing hormone, which in turn impacts the production of testosterone and oestrogen. For adolescents whose bodies are already riding a hormonal rollercoaster, this interference can lead to delayed puberty, reduced energy, and potentially hindered physical development. It serves as a reminder of how interconnected our systems are and how delicate this balance can be.

For children and teenagers, these findings highlight the importance of approaching serotonin-based treatments with care and nuance. Understanding its broader influence on hormonal health ensures we can support young people through these critical developmental years without risking their long-term well-being. It is not just about addressing symptoms. It is about safeguarding their future.

Jim Adams’ Research on Gut Toxins and Serotonin Dysfunction

In a recent study involving autistic children, Jim Adams and his team investigated the impact of gut-derived toxins on neurodevelopmental challenges. Their work focused on indoxyl sulfate, a neurotoxic byproduct of tryptophan metabolism, which was found at significantly elevated levels in these children. These higher levels were linked to sensory dysregulation, obsessive-compulsive behaviours, and mitochondrial dysfunction, highlighting how gut imbalances can ripple out to affect the brain and behaviour.

Indoxyl sulfate is produced when gut bacteria act on tryptophan. This byproduct is processed in the liver, but when gut dysbiosis intensifies the process, it results in a buildup of toxins that interfere with neural pathways and exacerbate behavioural challenges. While this study did not directly examine serotonin, it sheds light on how tryptophan metabolism can be diverted, influencing brain function in significant ways.

What makes this research so valuable is the ability to measure indoxyl sulfate alongside other metabolites like p-cresol sulfate and beta-casomorphins using a simple urine test. These tests uncover hidden gut dysfunction and help tailor interventions, further underscoring the critical link between the gut and brain.

 

Pinpointing the Root Causes of Serotonin Dysregulation

Understanding serotonin dysfunction requires comprehensive testing. Organic acids testing can reveal imbalances in serotonin precursors and mitochondrial health. Stool analysis identifies gut dysbiosis, inflammation, and digestive dysfunction. Thyroid panels assess energy deficits linked to hypothyroidism, while micronutrient testing uncovers deficiencies in key nutrients like selenium, magnesium, and B vitamins. Advanced urine tests, such as those that measure metabolites like indoxyl sulfate and beta-casomorphins, provide detailed insights into gut health and its influence on serotonin pathways.

Genetics also plays a fascinating role in serotonin metabolism. Variants in key genes that govern serotonin synthesis, transport, and breakdown can significantly influence how serotonin is managed in the body. For example, differences in the TPH2 gene, which affects serotonin production in the brain, or the MAOA gene, responsible for breaking down serotonin, can alter its levels and impact behaviours. With a simple cheek swab, it is possible to identify these genetic variations. When combined with urine metabolite testing, these tools offer a clearer picture of how different factors interact, paving the way for highly personalised strategies to support optimal health and well-being.

 

A Comprehensive Plan for Serotonin Balance

Addressing serotonin dysfunction involves more than simply increasing or decreasing serotonin levels. It requires a holistic approach that supports adrenal and thyroid function, reduces neuroinflammation, and restores gut health.

Balancing adrenal and thyroid function is key to regulating serotonin naturally. Nutrients such as selenium, iodine, magnesium, and zinc support energy production and reduce inflammation. Supplements like L-theanine or phosphorylated serine help balance cortisol levels, reducing stress-driven serotonin spikes.

Neuroinflammation can be managed with targeted interventions. Magnesium threonate and glycinate, which cross the blood-brain barrier, are effective at calming the nervous system and reducing oxidative stress. Vitamin D3 combined with K2 regulates immune responses and supports brain health. Natural anti-inflammatory agents like ginger and curcumin can also modulate excessive serotonin activity.

Restoring gut health is essential for reducing serotonin dysregulation. Probiotic strains like Bifidobacterium longum help restore microbiome balance, while dietary changes that eliminate inflammatory triggers like gluten and include gut-supportive foods like bone broth and ripe fruits provide essential nutrients. In cases where gut-derived toxins are a significant issue, binders such as activated charcoal can reduce the burden on the system.

In some situations, medical options like cyproheptadine, a serotonin receptor blocker, or low-dose aspirin, which has anti-inflammatory and serotonin-modulating properties, may be appropriate. These interventions should always be undertaken with professional oversight and as part of a broader, individualised plan.

 

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The Power of Food on Serotonin Balance

Diet plays a foundational role in regulating serotonin, particularly when it comes to balancing energy production and reducing stress-driven serotonin overproduction. A pro-metabolic approach focuses on nutrient-dense, easily digestible foods that reduce inflammation, stabilise blood sugar, and support overall cellular function.

It’s important to remember: you don’t have to make all these changes at once. Even introducing one small adjustment, like adding gelatine to a soup or swapping out a cooking oil for butter, can set the stage for significant improvements over time. These changes work cumulatively, and the key is to start where you feel comfortable and build from there.

Proteins low in tryptophan, such as gelatine, bone broth, and slow-cooked meats, are particularly beneficial. Gelatine is rich in glycine, an amino acid that helps balance the excitatory effects of serotonin and promotes restful sleep. Incorporating these into meals, such as adding gelatine to soups, stews, or homemade desserts, provides a steady protein source without driving serotonin precursors too high. Organ meats, like liver, can be included in moderation for their rich micronutrient profile, including iron, copper, and retinol, which are essential for energy production and metabolic health.

Easy-to-digest carbohydrates, such as ripe fruits and well-cooked root vegetables, play a critical role in stabilising blood sugar and reducing the stress hormone cortisol. Fruits like papaya, mango, stewed apples, and cantaloupe are excellent choices as they are naturally sweet, rich in vitamins, and gentle on the gut. Root vegetables, such as sweet potato, squash, and parsnips, provide a slow-burning energy source, supporting sustained blood sugar levels throughout the day.

Anti-inflammatory fats, such as butter, ghee, and coconut oil, are vital for reducing oxidative stress and supporting mitochondrial health. Coconut oil is particularly beneficial as it is rich in medium-chain triglycerides, which are easily converted into energy. Using these fats in cooking or as toppings on meals ensures a steady energy supply while reducing the burden of polyunsaturated fatty acids, which can contribute to inflammation.

Hydration is another key element that is often overlooked. Adding a pinch of unrefined sea salt to water not only supports adrenal function but also provides electrolytes needed for proper cellular activity. Coconut water, in small amounts, can also serve as a natural electrolyte source, especially for children prone to dehydration or fatigue.

 

Build Your Child’s Diet Around These Serotonin-Supporting Foods and Drinks

– Include a small glass of fresh orange juice with a pinch of salt at breakfast to provide easily absorbed carbohydrates, vitamin C, and hydration.

– Use bone broth as a base for soups or stews, ensuring a steady intake of gut-healing nutrients like collagen and glycine.

– Incorporate gelatine gummies made with fruit juice as a snack option, which are both child-friendly and supportive of serotonin balance.

– Pair ripe fruits with a small amount of protein or fat, such as a slice of mango with coconut flakes or apple slices with a dollop of butter, to support balanced blood sugar.

– Rotate protein sources to include slow-cooked beef, chicken thighs, lamb shank, or pork shoulder, which are lower in tryptophan and easier to digest compared to leaner cuts of meat.

By carefully curating meals to focus on these principles, it is possible to provide steady energy, reduce inflammation, and support a healthier serotonin balance. Remember, this approach isn’t about doing everything all at once. It’s about precision and progress, giving the body what it needs in small, manageable ways that fit into your family’s life. Every small step counts, and over time, these changes can make a profound difference.

 

A New Way Forward

This new perspective on serotonin challenges long-held assumptions and offers a more nuanced understanding of its role in children with autism, PANDAS, and PANS. By addressing the underlying drivers of serotonin dysfunction, whether gut dysbiosis, systemic inflammation, or energy deficits, it becomes possible to create a more targeted and effective plan for your child.

This is not about discarding serotonin-boosting treatments altogether but understanding when they are appropriate and when they might cause harm. By recognising serotonin’s dual nature and its complex role in the body, we can move away from a one-size-fits-all approach. Instead, we can embrace tailored interventions that consider the whole picture—your child’s biochemistry, genetics, and unique health needs.

Armed with the right tools and insights, you can take meaningful steps to improve your child’s well-being. It is about creating balance and harmony, supporting your child’s health in a way that is as individual as they are.

 

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IMPORTANT

The information provided in this article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. It is crucial to consult with medical doctors or qualified functional medicine practitioners to address specific health concerns and obtain personalised guidance tailored to individual needs. Never add any supplements to your plan until it has been assessed and approved by your medical doctor or a suitable qualified practitioner who is familiar with your health history. 

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References

1. Hill, Z.R., Flynn, C.K., & Adams, J.B. (2024). Indoxyl Sulfate and Autism Spectrum Disorder: A Literature Review. International Journal of Molecular Sciences, 25(23), 12973. https://doi.org/10.3390/ijms252312973
2. Gevi, F., Zolla, L., Gabriele, S., & Persico, A.M. (2016). Urinary metabolomics of young Italian autistic children supports abnormal tryptophan and purine metabolism. Molecular Autism, 7, 47. https://doi.org/10.1186/s13229-016-0109-5
3. Dieme, B., Mavel, S., Blasco, H., et al. (2015). Metabolomics study of urine in autism spectrum disorders using a multiplatform analytical methodology. Journal of Proteome Research, 14(11), 5273–5282. https://doi.org/10.1021/acs.jproteome.5b00699
4. Osredkar, J., Baškovic, B., Finderle, P., et al. (2023). Relationship between excreted uremic toxins and degree of disorder of children with ASD. International Journal of Molecular Sciences, 24(7), 7078. https://doi.org/10.3390/ijms24087078
5. Mrochek, J.E., Dinsmore, S.R., & Ohrt, D.W. (1973). Monitoring phenylalanine–tyrosine metabolism by high-resolution liquid chromatography of urine. Clinical Chemistry, 19(8), 927–936. https://doi.org/10.1093/clinchem/19.8.927
6. Rangel-Huerta, O.D., Gomez-Fernández, A., et al. (2019). Metabolic profiling in children with autism spectrum disorder with and without mental regression: Preliminary results from a cross-sectional case-control study. Metabolomics, 15(9), 99. https://doi.org/10.1007/s11306-019-1562-x
7. Kennedy, D.O. (2016). B Vitamins and the brain: Mechanisms, dose, and efficacy—A review. Nutrients, 8(2), 68. https://doi.org/10.3390/nu8020068
8. Ben-Sheetrit, J., Hermon, Y., Birkenfeld, S., Gutman, Y., Csoka, A. B., & Toren, P. (2023). Estimating the risk of irreversible post-SSRI sexual dysfunction (PSSD) due to serotonergic antidepressants. Annals of General Psychiatry, 22(1), 15. https://doi.org/10.1186/s12991-023-00447-0
9. Alotoom, O. M., & Marwaha, R. (2023). Association between SSRIs and delayed puberty in children. Journal of the American Academy of Child & Adolescent Psychiatry, 62(10), S2. https://doi.org/10.1016/j.jaac.2023.09.136

Reference to Ray Peat

Ray Peat’s theories on serotonin as a stress signal are widely discussed in alternative health circles and have influenced perspectives on serotonin metabolism. While not published in peer-reviewed journals, his ideas align with emerging research linking serotonin to neuroinflammation and systemic stress. For further reading, see his independent articles at Ray Peat’s Website (https://raypeat.com).