As we dive into the complex and beautiful neurochemical cocktail that fuels our brains, serotonin is a bit of an enigma. Research shows that serotonin plays an important role in regulating mood, appetite, sleep, and dreaming. It can have both a sedating or stimulating effect and this is somehow related to the flow of thoughts through your mind. Though neuroscience is in its infancy, we can still gain a lot of personal insight through exploring research being conducted across a number of fields, and comparing it to what we have felt or experienced internally.
So what is serotonin? It is a neurotransmitter, which means its a type of chemical that relays brain signals from one area of the brain to another. Nearly every one of the 40 million brain cells we have, are influenced either directly or indirectly by serotonin. Many researchers believe an imbalance in serotonin levels leads to depression. If there are any biochemical glitches like a shortage of tryptophan, the chemical from which serotonin is made, or a lack of receptor sites able to receive serotonin, or serotonin is unable to reach the receptor sites, then researchers say this can cause depression, as well as Obsessive Compulsive Disorders, anxiety, panic and excess anger.
Serotonin has been in the spotlight for its potential role in combatting conditions such as anxiety and depression, which affect many people. Prescription medications like Prozac, Paxil, and Zoloft are in a class of drugs called selective serotonin re-uptake inhibitors (SSRIs). The theory is that these drugs are able to modify the extracellular level of serotonin in the brain by limiting its reabsorption. It is believed that by increasing the level of serotonin surrounding the presynaptic cell the symptoms of depression will be erased. However, there is much research that now refutes this theory; claiming that anti-depressants are glorified and expensive placebos. We know that serotonin plays some role in moods (and mood disorders including depression) but we are not exactly sure how, to what degree, and why.
A study from the laboratory of long-time depression researcher Eva Redei, presented at the Neuroscience 2009 conference appears to topple two strongly held beliefs about depression. One is that stressful life events are a major cause of depression. The other is that an imbalance in neurotransmitters in the brain triggers depressive symptoms. – Northwestern University Feinberg School of Medicine
LSD has been in the news lately due to the release of recent brain scans of people under its influence. It doesn’t take a research laboratory to tell that LSD has a profound effect on peoples’ mood, and perceptions. Just take a look at the numerous artists, like the Beatles, Steve Jobs, Alex Grey, or Dock Ellis who have pitched a no-hitter on LSD. The enhanced focus and hallucinatory, dream-like experiences on this substance are attributed to the fact that LSD suppresses the serotonin system. The result is an induced dream-state while wide awake. MDMA (ecstasy) is another psychedelic that influences mood, by causing the brain to become flooded with serotonin.
Our bodies produces endogenous DMT (dymethyltryptamine), which is a structural analog of both serotonin and melatonin. DMT attaches to serotonin receptor sites which exist in high concentrations on nerve cells in brain areas. Occurring naturally in the plant kingdom and in mammals, DMT is the psychoactive component of Ayahuasca, the visionary Amazonian brew. Not surprisingly, many have attested to the ability of Ayahuasca to cure depression.
…the brain is where DMT exerts its most interesting effects. There, sites rich in these DMT-sensitive serotonin receptors are involved in mood, perception, and thought. Although the brain denies access to most drugs and chemicals, it takes a particular and remarkable fancy to DMT. It is not stretching the truth to suggest that the brain “hungers” for it.” – DMT: The Spirit Molecule by Rick Strassman, M.D. (2001)
Dreaming and sleep
High levels of serotonin are associated with wakefulness, and low levels are associated with sleep. Therefore it comes as no surprise that the REM sleep cycle (during which most of our dreams occur) happens when the serotonin system shuts off during sleep. Melatonin plays a supporting role to serotonin in this function because it prepares the body for darkness and sleep, regulating our circadian rhythm. As you can see, sleep disorders, moods, ability to focus, alertness, and dreams are quite entwined with the level of serotonin in our brains.
The Brain-Gut Connection
Believe it or not, much of the serotonin in our bodies (up to 95%) resides within our gut. The brain and gut communicate back and forth through the central nervous system and the gastrointestinal tract. Serotonin functions as a key neurotransmitter at both ends of this network. An amino acid, tryptophan, is converted into 5-HTP in the small intestine. 5-HTP is then converted to serotonin that is later converted into melatonin. (See tryptophan-rich foods listed below)
So, the question most people are probably asking is: can I increase my serotonin levels, and if so how?
If you have ever experienced a gut feeling then you may have been tuning in to what researchers call the second brain which is the enteric nervous system. This part of the gut consists of sheaths of neurons embedded in the walls of the long tube of our alimentary canal, which runs from our throat to our anus. Not surprisingly, much of our brain processes are affected by mood which are a direct result of our gut health.
Serotonin is a bit of a mystery because excess levels of it in the gut are also associated with diseases like irritable bowel syndrome. A recent Nature Medicine Study done with rats using a drug that inhibited serotonin in the gut appears to have cured osteoporosis. There also seems to be a link to autism yet the research is still in its early stages. People who take SSRI’s (anti depressants that inhibit serotonin) often have digestion issues as a result. So keep eating sauerkraut, and other live cultures like jun or kombucha to keep healthy flora in your digestive tract. The irony is that so many of us focus on our thoughts, meditation, etc. when the issue may be rooted in our digestion.
How to Increase your Serotonin
It is not so simple to determine the perfect amount of serotonin needed because it appears that too much and too little can each have both beneficial and detrimental effects. It does however seem that increasing ones serotonin levels will help with focus, energy, and mood if you are feeling low. Eating foods rich in tryptophan helps the body synthesise 5-HTP, which can then be turned into serotonin. These foods include but are not limited to: nuts, seeds, tofu, cheese, red meat, chicken, turkey, fish, oats, beans, lentils, and eggs. There are 5-HTP supplements available but it is preferable to source nutrients from whole and organic foods.
Research shows that serotonin production is a two-way street with mood. By doing things that elevate your mood, you will increase serotonin production which will get you in an even better mood as the cycle feeds on itself. Yoga and exercise have proven to be beneficial in mood elevation, especially when combined with being outdoors. There is evidence which suggests that exposure to bright light increases serotonin, and people often employ full-spectrum lights in the winter to keep from acquiring SAD (Seasonal Affective Disorder).
We humans have inherited quite an awesome and complex physiology. Serotonin is perhaps one of the most mysterious and important of all neurotransmitters and being more aware of its interactions will hopefully bring about improvements in your moods and dreams.