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What is serotonin? Your mood and sleep chemical explained
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Have you ever heard of the happiness chemicals? Your feel-good chemical serotonin is one of them. Serotonin is a brain messenger that plays a vital role in regulating various processes in the human body. Its discovery can be traced back to the late 1930s when Italian scientist Vittorio Erspamer isolated a substance from the gastrointestinal tract[1 Trusted Source 1999 - Neuropsychopharmacology Evidence review The Discovery of Serotonin and its Role in Neuroscience ] . Initially called enteramine, it was later renamed serotonin by Maurice Rapport and colleagues almost 15 years later. In 1953, Betty Twarog, a Harvard PhD candidate, discovered serotonin in the mammalian brain, challenging the belief that it was only found in the gut. This discovery paved the way for understanding serotonin's crucial role in brain functioning like emotions and behaviour, marking a significant milestone in the field of neuroscience. Let’s see what the effects of brain serotonin are, how it’s involved in mood conditions and how you can increase your serotonin levels safely.
Table of Contents
- How does serotonin make you feel?
- What happens when serotonin is low?
- What depletes serotonin?
- Does lack of serotonin cause depression?
- Is serotonin high or low in anxiety?
- What food has the most serotonin?
- How can I increase my serotonin levels quickly?
- Tryptophan vs 5-htp
- What is the best supplement for serotonin?
- Natural serotonin boosters: St. John's Wort vs 5-htp
- Serotonin supplements & SSRIs: safety and side effects
- Does serotonin depletes dopamine?
- What stimulates serotonin release?
How does serotonin make you feel?
Serotonin is one of the happiness chemicals because it promotes feelings of well-being and emotional stability. The primary serotonin function is stabilising mood by influencing the brain circuits that control emotions. Additional serotonin benefits showcase improved sleep patterns and quality. You’re probably questioning: Really, serotonin? What does it do for sleep? In short, serotonin stimulates your sleep hormone melatonin and by this the parts of your brain that control the sleep-wake cycle, helping you fall asleep faster and wake up when the time’s right. Wondering which makes you happy -serotonin or dopamine? Both dopamine and serotonin contribute to feelings of happiness - while serotonin regulates mood, dopamine is associated with pleasure and reward. This said serotonin is the chemical responsible for mood regulation, tying it directly to your feelings of happiness.
Can serotonin help you sleep?
Yes, serotonin plays a role in regulating sleep patterns as it’s the building block of your sleep hormone melatonin. Melatonin is found in all plant and animal species and is produced at night when UV light levels drop. Does melatonin increase serotonin? It’s actually the other way around - high serotonin levels during the day boost evening melatonin levels, helping your sleep quality. How important is serotonin for sleep? In short, very. Your brain only makes melatonin from serotonin. Therefore, it’s very important to keep your serotonin levels up so it can help you regulate your sleep-wake cycle. Studies have also shown that both melatonin and serotonin play an important part in sleep quality. Melatonin for sleep has been around for a while. It actually holds 2 health claims from the European Food Safety Authority. A review of the evidence from 35 studies showed that melatonin supplementation significantly reduced the time to fall asleep and increased total sleep time in people with insomnia[2 Trusted Source 2014 - Nutrition Journal Systematic review and meta-analysis The effectiveness of melatonin for promoting healthy sleep: A rapid evidence assessment of the literature ] . Additionally, people with sleep disorders like jet lag or shift work disorder often experience improved sleep when taking melatonin supplements to resynchronize their body clocks[2 Trusted Source 2014 - Nutrition Journal Systematic review and meta-analysis The effectiveness of melatonin for promoting healthy sleep: A rapid evidence assessment of the literature ] ,[3 Trusted Source 2018 - British Journal of Pharmacology Evidence review New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation ] . When researching serotonin, animal studies found that its release promotes sleep, while a literature review concluded serotonin does in fact promote melatonin levels[4 Trusted Source 2019 - Caltech Blog article Settling the Debate on Serotonin’s Role in Sleep ] ,[5 Trusted Source 2021 - Proceedings of the National Academy of Sciences Evidence review Serotonin modulates melatonin synthesis as an autocrine neurotransmitter in the pineal gland ] .
What happens when serotonin is low?
While higher levels help you regulate your mood, low serotonin levels can contribute to conditions such as depression and sleep disturbances. An evidence review showed that people with depression who were unmedicated had lower levels of the primary building block of serotonin called tryptophan[2 Trusted Source 2014 - Nutrition Journal Systematic review and meta-analysis The effectiveness of melatonin for promoting healthy sleep: A rapid evidence assessment of the literature ] . Whilst the answer to why this occurs is still being researched, 3 studies have confirmed that low serotonin levels affect sleep[6 Trusted Source 2015 - American Journal of Physiology. Regulatory, Integrative and Comparative Physiology Animal study The sleep-wake cycle and motor activity, but not temperature, are disrupted over the light-dark cycle in mice genetically depleted of serotonin ] ,[7 Trusted Source 2023 - Scientific Reports Human study An exploratory study on the association between serotonin and sleep breathing disorders ] ,[8 Trusted Source 2010 - Sleep Human study Sleep and Rhythm Consequences of a Genetically Induced Loss of Serotonin ] . First of all, an animal study on mice showed that mice with serotonin deficiency exhibited disrupted sleep-wake cycles and experienced insomnia-like symptoms with frequent awakenings during the night[6 Trusted Source 2015 - American Journal of Physiology. Regulatory, Integrative and Comparative Physiology Animal study The sleep-wake cycle and motor activity, but not temperature, are disrupted over the light-dark cycle in mice genetically depleted of serotonin ] . Secondly, another human study showed that lower serotonin levels were associated with an increase in the number of breathing problems that happen during sleep like obstructive and central apnea events, contributing to sleep breathing disorders that worsen sleep quality[7 Trusted Source 2023 - Scientific Reports Human study An exploratory study on the association between serotonin and sleep breathing disorders ] . Lastly, a case study on a patient with a disorder that causes serotonin deficiency found they experienced sleep disturbances like frequent awakenings, irregular movements during sleep, and problems initiating and maintaining sleep[8 Trusted Source 2010 - Sleep Human study Sleep and Rhythm Consequences of a Genetically Induced Loss of Serotonin ] . To address this topic more in-depth, let’s take a look at what causes serotonin deficiency.
What depletes serotonin?
Chronic stress, poor diet and conditions like inflammation are usually the main reasons behind lower serotonin levels. A literature review concluded that chronic stress can lead to changes in serotonin levels in the brain[9 Trusted Source 1999 - Neuropsychopharmacology Evidence review Serotonin and Stress ] . This suggests that chronic stress may disrupt normal serotonin functioning. Diet also plays a role in serotonin depletion with an extensive review of 17 studies finding that restricting the intake of serotonins building block tryptophan contributed to low mood in those with a family history of depression[10 Trusted Source 2023 - Molecular Psychiatry Systematic review and meta-analysis The serotonin theory of depression: A systematic umbrella review of the evidence ] . Similarly, tryptophan can be converted differently during inflammation. This appears to decrease serotonin levels and serotonin transportation and messaging through the brain[11 Trusted Source 2011 - Psychoneuroendocrinology/span> Evidence review Inflammation-Associated Depression: From Serotonin to Kynurenine ] .
Does lack of serotonin cause depression?
Serotonin and depression have been closely linked for over 60 years; while serotonin deficiency is not the sole cause of depression, it’s a significant contributing factor. The idea of depression being the result of abnormalities in brain chemicals, particularly your feel-good chemical, has been influential for decades and provides an important justification for the use of antidepressants[10 Trusted Source 2023 - Molecular Psychiatry Systematic review and meta-analysis The serotonin theory of depression: A systematic umbrella review of the evidence ] . Let’s see how do SSRIs work to understand the theory better. How does an SSRI actually work? SSRIs work by blocking the usage of serotonin in the brain, making more serotonin available for release[12 Trusted Source 2020 - Personalized Medicine in Psychiatry/span> Human clinical study An updated classification of antidepressants: A proposal to simplify treatment ] . They are yet to develop an antidepressant that would address the amount of serotonin produced. Despite the chemical imbalance theory of depression prevailing for many years, it’s now suggested that multiple factors like the conversion of tryptophan and also cell dysfunction contribute to the development of depression.
Is serotonin high or low in anxiety?
Serotonin levels can be either high or low in individuals with anxiety disorders, suggesting that the relationship between serotonin and anxiety is complex. Many studies, however, have shown a link between excessive levels of the stress hormone cortisol and lowered serotonin in the brain[13 Trusted Source 2001 - Cognitive, Affective & Behavioral Neuroscience/span> Human clinical study Correlation between cortisol level and serotonin uptake in patients with chronic stress and depression ] ,[14 Trusted Source 2005 - The International Journal of Neuroscience/span> Evidence review Cortisol decreases and serotonin and dopamine increase following massage therapy ] . The theory is that by promoting more active serotonin to boost mood, the effects of excessive cortisol in the body can be counteracted, however, more research is needed before concluding anything.
What food has the most serotonin?
Dried pumpkin and squash seeds are some of the foods highest in serotonin’s building block tryptophan[15 Trusted Source My Food Data/span> Database sourced from the USDA Food Data Central Foods Highest in Tryptophan ] . Which additional foods contain serotonin? Protein-rich foods like eggs, tofu and cheese all contain a decent amount of tryptophan. So, how to naturally produce serotonin from tryptophan? Your gut and serotonin are connected. Tryptophan gets absorbed in your gut where it gets transformed into serotonin that can help with various body functions. However, the so-called gut serotonin is different to brain serotonin. Does the gut affect serotonin? While more than 90% of the body's serotonin is produced in the gut after ingesting tryptophan-rich foods, serotonin itself is unable to cross the blood-brain barrier where it would benefit your mood[16 Trusted Source 2012 - ACS Chemical Neuroscience/span> Evidence review Celebrating Serotonin ] . Here’s what can.
How can I increase my serotonin levels quickly?
While lifestyle changes like a healthy diet full of tryptophan-rich foods can gradually increase serotonin levels, opting for a 5-htp supplement allows you to increase the levels quickly.
Tryptophan vs 5-htp
After ingesting tryptophan, this compound travels to your gut. In order to cross the blood-brain barrier, tryptophan has to bind with a transporter molecule. Your body uses less than 3% of food’s tryptophan to make brain serotonin[16 Trusted Source 2012 - ACS Chemical Neuroscience/span> Evidence review Celebrating Serotonin ] . In the brain, tryptophan is converted to 5-htp. That is why 5-htp is the answer to how to increase serotonin in the brain as it’s the direct building block to serotonin that can enter the brain. 5-htp is then converted to serotonin (5-ht) which can be for mood-regulating purposes.
What is the best supplement for serotonin?
When choosing the best serotonin supplement, consider quality and dose. You should opt for a natural serotonin supplement that provides you with at least 100 mg of 5-htp which is naturally made by your body from serotonin’s building block tryptophan. brain feed developed a natural way to boost serotonin by extracting 5-htp from the top natural source, the Griffonia seeds, providing you with 100 mg of 5-htp in one single capsule. Get to know more about what is 5-htp, its benefits and safety.
Natural serotonin boosters: St. John's Wort vs 5-htp
As opposed to 5-htp which increases the production and by that the overall levels of serotonin, St. John's Wort is believed to slow down the process that normally absorbs serotonin back into brain cells, resulting in more serotonin available for mood regulation[17 Trusted Source 2022 - Naunyn-Schmiedeberg’s Archives of Pharmacology/span> Evidence review St. Johnʼs wort (Hypericum perforatum) and depression: what happens to the neurotransmitter systems? ] ,[18 Trusted Source 2022 - Cureus/span> Systematic review and meta-analysis Advantages and Disadvantages of Using St. John’s Wort as a Treatment for Depression ] . This mechanism of action is similar to that of SSRIs. Similar to antidepressants, St John’s Wort has a myriad of side effects, reportedly reacting with over 800 medications[19 Trusted Source 2017 - Be Brain Fit/span> Blog article Benefits (and Risks) of St. John's Wort for Depression ] . This combined with a lack of evidence for the plant’s positive impact, prompted the American Food and Drug Administration (FDA) to deny the St John’s Wort products to be licensed for prescription or over-the-counter treatments[20 Trusted Source 2017 - Medical News Today/span> Blog article St. John's Wort: Should I use it? ] . 5-htp remains a safer and more well-researched alternative.
Serotonin supplements & SSRIs: safety and side effects
Despite being considered safe, serotonin side effects can happen to some when taking supplements. What are the signs of too much serotonin? Excessive serotonin levels can lead to a rare condition called serotonin syndrome, making you feel agitated and confused. What is serotonin syndrome? It’s a term describing your body having too much serotonin and it could happen to people who are taking SSRIs while supplementing with other serotonin-boosting supplements like St John’s Wort or 5-htp. What are the symptoms of serotonin syndrome? Sweating, dilated pupils, high body temperature and irregular heartbeats are all additional symptoms of serotonin syndrome. That’s why it’s important to consider your antidepressant intake when figuring out if supplementation is the best option for you.
Does serotonin depletes dopamine?
There’s a common misconception out there that increasing serotonin levels equals decreasing dopamine levels. Although serotonin and dopamine form one part of the happiness chemicals and definitely work together, serotonin has yet to be proven to deplete dopamine levels. While some articles have hypothesized that, they have later been retracted because of invalid information. More work needs to be done on this topic before this “more serotonin equals less dopamine” equation is approved.
What stimulates serotonin release?
Now you know what serotonin is and how to boost it - here’s how to release it. A healthy serotonin release can be stimulated by bright light exposure and exercise. Despite the common belief that exercise will make you happier, there’s an important step in the serotonin pathway that happened before. Like charging your car or putting petrol in it for it to get you places, you first need to get your body fueled up with enough building blocks to produce your feel-good chemical. After serotonin is produced, it’s then stored in the brain and used when needed. To feel the benefits of serotonin, this chemical needs to be released first. So, how to stimulate serotonin release in your day-to-day lives? Exercise releases your feel-good chemical which can help counteract the feelings of low energy and sadness[21 Trusted Source 2009 - Biological Rhythm Research/span> Evidence review Seasonal affective disorder and exercise treatment: A review ] ,[22 Trusted Source 2011 - Scandinavian Journal of Medicine & Science in Sports/span> Human clinical study An examination of serotonin and psychological variables in the relationship between exercise and mental health: Serotonin, exercise, and mental health ] . Another one of the most effective strategies for stimulating serotonin release is spending as much time outside as possible, getting natural sunlight or opting for light therapy for depression, also known as phototherapy. For example, a meta-analysis analysed 19 studies and found that light therapy is one of the most effective seasonal affective disorder treatments[23 Trusted Source 2020 - Psychotherapy and Psychosomatics/span> Systematic review and meta-analysis The Efficacy of Light Therapy in the Treatment of Seasonal Affective Disorder: A Meta-Analysis of Randomized Controlled Trials ] . So, opt for running, walking or cycling outside or try a bit of yoga under light therapy to help your body release serotonin, helping you regulate your mood.
All in all, serotonin is an important factor when it comes to life quality. It helps you regulate your emotions hence the name the feel-good chemical. Stay on top of it by supplying your body with the right amount of its building block to reap the benefits.
[1] Whitaker-Azmitia, P. M. (1999). The Discovery of Serotonin and its Role in Neuroscience. Neuropsychopharmacology, 21(1), 2–8. https://www.nature.com/articles/1395355
[2] Costello, R. B., Lentino, C. V., Boyd, C. C., O’Connell, M. L., Crawford, C. C., Sprengel, M. L., & Deuster, P. A. (2014). The effectiveness of melatonin for promoting healthy sleep: A rapid evidence assessment of the literature. Nutrition Journal, 13(1), 106. https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-13-106
[3] Zisapel, N. (2018). New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. British Journal of Pharmacology, 175(16), 3190–3199. https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bph.14116
[4] Dajose, L. (2019). Settling the Debate on Serotonin’s Role in Sleep. Caltech. https://www.caltech.edu/about/news/settling-debate-serotonins-role-sleep
[5] Lee, B. H., Hille, B., & Koh, D.-S. (2021). Serotonin modulates melatonin synthesis as an autocrine neurotransmitter in the pineal gland. Proceedings of the National Academy of Sciences, 118(43), e2113852118. https://www.pnas.org/doi/full/10.1073/pnas.2113852118
[6] Solarewicz, J. Z., Angoa-Perez, M., Kuhn, D. M., & Mateika, J. H. (2015). The sleep-wake cycle and motor activity, but not temperature, are disrupted over the light-dark cycle in mice genetically depleted of serotonin. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 308(1), R10–R17. https://journals.physiology.org/doi/full/10.1152/ajpregu.00400.2014
[7] Wieckiewicz, M., Martynowicz, H., Lavigne, G., Lobbezoo, F., Kato, T., Winocur, E., Wezgowiec, J., Danel, D., Wojakowska, A., Mazur, G., & Smardz, J. (2023). An exploratory study on the association between serotonin and sleep breathing disorders. Scientific Reports, 13, 11800. https://www.nature.com/articles/s41598-023-38842-y
[8] Leu-Semenescu, S., Arnulf, I., Decaix, C., Moussa, F., Clot, F., Boniol, C., Touitou, Y., Levy, R., Vidailhet, M., & Roze, E. (2010). Sleep and Rhythm Consequences of a Genetically Induced Loss of Serotonin. Sleep, 33(3), 307–314. https://academic.oup.com/sleep/article-abstract/33/3/307/2454473?redirectedFrom=fulltext
[9] Chaouloff, F., Berton, O., & Mormède, P. (1999). Serotonin and Stress. Neuropsychopharmacology, 21(1), 28–32. https://www.nature.com/articles/1395332
[10] Moncrieff, J., Cooper, R. E., Stockmann, T., Amendola, S., Hengartner, M. P., & Horowitz, M. A. (2023). The serotonin theory of depression: A systematic umbrella review of the evidence. Molecular Psychiatry, 28(8), 3243–3256. https://www.nature.com/articles/s41380-022-01661-0
[11] Dantzer, R., O’Connor, J. C., Lawson, M. A., & Kelley, K. W. (2011). Inflammation-Associated Depression: From Serotonin to Kynurenine. Psychoneuroendocrinology, 36(3), 426–436. https://www.sciencedirect.com/science/article/abs/pii/S0306453010002453?via%3Dihub
[12] Alvano, S. A., & Zieher, L. M. (2020). An updated classification of antidepressants: A proposal to simplify treatment. Personalized Medicine in Psychiatry, 19–20, 100042. https://www.personalizedmedpsych.com/article/S2468-1717(18)30028-0/fulltext
[13] Tafet, G. E., Idoyaga-Vargas, V. P., Abulafia, D. P., Calandria, J. M., Roffman, S. S., Chiovetta, A., & Shinitzky, M. (2001). Correlation between cortisol level and serotonin uptake in patients with chronic stress and depression. Cognitive, Affective & Behavioral Neuroscience, 1(4), 388–393. https://link.springer.com/article/10.3758/CABN.1.4.388
[14] Field, T., Hernandez-Reif, M., Diego, M., Schanberg, S., & Kuhn, C. (2005). Cortisol decreases and serotonin and dopamine increase following massage therapy. The International Journal of Neuroscience, 115(10), 1397–1413. https://www.tandfonline.com/doi/full/10.1080/00207450590956459
[15] Foods Highest in Tryptophan (n.d.). My Food Data. https://tools.myfooddata.com/nutrient-ranking-tool/tryptophan/all/highest/grams/common/no
[16] Andrews, A. M. (2012). Celebrating Serotonin. ACS Chemical Neuroscience, 3(9), 644–645. https://pubs.acs.org/doi/10.1021/cn300137q
[17] Kholghi, G., Arjmandi-Rad, S., Zarrindast, M.-R., & Vaseghi, S. (2022). St. Johnʼs wort (Hypericum perforatum) and depression: what happens to the neurotransmitter systems? Naunyn-Schmiedeberg’s Archives of Pharmacology, 395(6), 629–642. https://link.springer.com/article/10.1007/s00210-022-02229-z
[18] Canenguez Benitez, J., Hernandez, T., Sundararajan, R., Sarwar, S., Arriaga, A., Khan, A., Matayoshi, A., Quintanilla, H., Kochhar, H., Alam, M., Mago, A., Hans, A., & Benitez, G. (2022). Advantages and Disadvantages of Using St. John’s Wort as a Treatment for Depression. Cureus, 14(9), 29468. https://www.cureus.com/articles/94821-advantages-and-disadvantages-of-using-st-johns-wort-as-a-treatment-for-depression#!/
[19] Alban, D. (2017). Benefits (and Risks) of St. John's Wort for Depression. Be Brain Fit. https://bebrainfit.com/st-johns-wort-benefits-depression
[20] Nordqvist, C. (2017). St. John's Wort: Should I use it? Medical News Today. http://www.medicalnewstoday.com/articles/174928.php
[21] Peiser, B. (2009). Seasonal affective disorder and exercise treatment: A review. Biological Rhythm Research, 40(1), 85–97. https://www.tandfonline.com/doi/abs/10.1080/09291010802067171
[22] Wipfli, B., Landers, D., Nagoshi, C., & Ringenbach, S. (2011). An examination of serotonin and psychological variables in the relationship between exercise and mental health: Serotonin, exercise, and mental health. Scandinavian Journal of Medicine & Science in Sports, 21(3), 474–481. https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0838.2009.01049.x
[23] Pjrek, E., Friedrich, M.-E., Cambioli, L., Dold, M., Jäger, F., Komorowski, A., Lanzenberger, R., Kasper, S., & Winkler, D. (2020). The Efficacy of Light Therapy in the Treatment of Seasonal Affective Disorder: A Meta-Analysis of Randomized Controlled Trials. Psychotherapy and Psychosomatics, 89(1), 17–24. https://karger.com/pps/article-abstract/89/1/17/289795/The-Efficacy-of-Light-Therapy-in-the-Treatment-of?redirectedFrom=fulltext
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