The mental health status of populations is a global problem. The World Health Organization (WHO) estimates that 300 million people worldwide suffer from depression, while 260 million patients exhibit some form of anxiety.
One in 4 people will suffer from a mental disorder throughout their lifetime and, unfortunately, most patients in low-income countries will not have access to adequate treatment.
With these numbers in hand, there is a need for research in the psychiatric and psychological field to treat emotional problems, but also in the biological field to understand the biochemical bases which encourage them (or cause). While it is difficult for us to recognize this as thinking beings, there is no doubt that humans are our chemistry and therefore we are at the mercy of our body’s metabolic pathways and the genetic load that defines us. as individuals.
Based on that premise, here we will focus on dissecting the nature of serotonin, a neurotransmitter synthesized from tryptophan in animals and plants, involved in a myriad of physiological and psychological processes.
Serotonin and the human body
Serotonin or 5-hydroxytryptamine (5-HT) is a neurotransmitter found mainly in the intestinal tract and blood platelets (90% of the total), while the remaining 10% is synthesized in the neurons of the brain. This neurotransmitter is essential in human behavior because it is involved in processes such as everyday behavior, emotions and memory.
We explore what this chemical does emotionally in patients in the following lines, but first we find it interesting to expose some organ / disease processes that are affected.
Serotonin promotes clotting when there is a wound because the platelets travel to the lesion and release it.. Because it is a neurotransmitter associated with nerve activation in general, serotonin promotes the release into the bloodstream of these types of cells to prevent problems caused by injury when experimenting with the environment.
The vasoconstriction produced by this neurotransmitter prevents the patient from bleeding.
In general, this reduction in the perimeter of the blood vessels occurs in those closest to the skin, since these are the most at risk of receiving wounds from external elements; it is an adaptation to survive in hostile environments.
2. Cardiac arrhythmias
5-HT increases the entry of calcium into myocytes, which in excess it results in accelerated contractions of the heart. Shaking, nervousness, and restlessness are other symptoms of excess serotonin, although other causes are involved, such as our reaction to the first symptoms.
Excess neuronal serotonin is associated with seizures and, consequently, to epileptic diseases. However, this does not mean that serotonin is inherently bad; this is a quantitative problem, because as we have seen, in the vast majority of cases this neurotransmitter is not only a normal and natural part of our organism, but also beneficial for us.
4. Metabolic and endocrine processes
A high and prolonged concentration of circulating serotonin reduces bone mineral density, but in general this type of biological mechanism rarely leads to problems due to bone fragility.
The psychological effects of serotonin
With all of this data, you can see that serotonin has multiple functions in the body, some good in the short term and others that can turn negative if they persist over time. Serotonin deficiency is associated with listless, sad, and discouraged people, while excess is linked to nervousness, sweating, tremors, anxiety, and other events. Is it true?
The scientific article Understanding the Role of Serotonin in Psychiatric Illness, published in the medical journal F1000 Research, helps us to reliably understand the effects of serotonin at the individual psychological level. Before claiming that “serotonin is the compound of happiness” we need to base our knowledge on data.
First of all, it should be noted that there is clear scientific evidence capable of linking serotonergic dysfunctions in various psychiatric pathologies. Some are depression, anxiety disorders, eating disorders, schizophrenia, autism, and aggressive behavior, among others. We explore some of these causalities.
1. Serotonin and depression
Low levels of circulating serotonin have always been associated with depression, but it’s unclear exactly which comes first.. Is depression due to a lack of serotonin or a lack of serotonin through continuous depression?
Beyond this debate, the World Psychiatric Association (WPA) has things to say about this correlation. In the review article What does serotonin have to do with depression ?, this professional organization questions the absolute and compelling historical (and unfounded) relationship between depression and serotonin. Healthy people who are deprived of tryptophan in their diet (the precursor to serotonin) do not have depressive tendencies, causality therefore falls on its own by its own weight.
Yes, there are cases in which the lack of serotonin or its functioning can promote depression in patients with certain specificities, but this reality is neither necessary nor obligatory. To some extent, in the psychiatric field, it must be said that the lack of serotonin causes depression is considered to be lacking in truth.
2. Serotonin and anxiety
Selective Serotonin Reuptake Inhibitors (SSRIs) are drugs used to treat chronic anxiety., it is therefore clear that this neurotransmitter plays a certain role in its appearance.
However, we find a barrier similar to the previous case: some studies with animal models give anxiolytic properties to serotonin, while other arguments place it as an anxiogenic. This isn’t necessarily bad or reflects lies, as that only underscores the complexity of the neurotransmitter we have on hand.
Studies such as The Serotonin System and Anxiety explore the clear roles of serotonin and its concentrations on the development of serotonin circuits and anxiety responses in animal models, but there is still a long way to go.
3. Serotonin and schizophrenia
Hypotheses linking serotonin to schizophrenia suggest the trophic role during development and the interactions of this neurotransmitter with the dopaminergic system. For example, as the medical journal The Neurobiological Basis of Schizophrenia indicates, an increase in central serotonergic tone has been suggested in recent years in patients with schizophrenia.
It is postulated that these patients exhibit dopaminergic hypofunction in the prefrontal cortex due, in part, to the inhibitory action of excess serotonin at this particular level. For this reason, serotonin inhibitor drugs would improve symptoms in these clinical patients.
Serotonin and its complexity are not easy to study
With all these lines, we have seen that, in the world of science, not everything is what it seems. Serotonin is therefore known as the “neurotransmitter of happiness” their excessive release after consuming certain drugs or experiencing extremely pleasurable events is associated with momentary joy and euphoria. This correlation is fairly clear, but exploring the long-term effects of this neurotransmitter in patients with the disorders psychological is a whole different matter.
Even the most established basis of all (less serotonin results in depression) is today questioned by professional bodies, because this causality is not always respected.
On the other hand, there is no need to be alarmed at the idea that serotonin is involved in the development of psychological and psychiatric disorders. Given that this substance is one of the main neurotransmitters in the brain and is present throughout our Central Nervous System, it would be strange if it remained totally outside the emergence of these phenomena. Being more or less directly involved in psychopathologies does not mean that the presence of serotonin in our body is a problem..
Therefore, it is advisable to keep a critical mind and always seek professional sources when educating yourself about the effects of different hormones and compounds on your body. Everything is not as clear as it seems, and in many cases, miraculous properties are attributed to certain chemicals to make a profit. In the human body, complexity and multifunctionality take precedence over any compelling formula.
- Berger, M., Gray, JA and Roth, BL (2009). The expanded biology of serotonin. Annual Journal of Medicine, 60, 355-366.
- Cowen, PJ and Browning, M. (2015). What Does Serotonin Have To Do With Depression? Global Psychiatry, 14 (2), 158.
- Gordon, JA and Hen, R. (2004). The serotonin system and anxiety. Neuromolecular Medicine, 5 (1), 27-40.
- Marazziti, D. (2017). Understand the role of serotonin in psychiatric illnesses. F1000 research, 6.
- Mohammad-Zadeh, LF, Moses, L. and Gwaltney-Brant, SM (2008). Serotonin: a review. Journal of Pharmacology and Veterinary Therapeutics, 31 (3), 187-199.
- Saiz Ruiz, J., Vega Sánchez, DC, & Sánchez Páez, P. (2010). Neurobiological basis of schizophrenia. Clinique et Santé, 21 (3), 235-254.