Serotonin Deficiency: What to Look Out For

Shannon V. McHugh, PsyD
September 9, 2019

Everyone wants to feel healthy and happy, and for all of us, this involves a specific neurotransmitter that our body produces naturally called serotonin. Researchers call this chemical the “happy chemical”, because it is one of the key components within our body that helps us feel calm, relaxed, and… well, happy! Serotonin does a lot of other things in addition to helping us feel good, though; it regulates our sleep, digestion and appetite, and many other things as well. Studies have shown that almost 95% of the serotonin we produce is located in the gastrointestinal tract and the following 5% is located in the brainstem. This is why so many mental health professionals are beginning to link nutritional health to mental health and why people are suggesting that there is much more of a connection between the gut and the mind than may have been originally thought.


When someone has a serotonin deficiency, there are many different symptoms that can arise, both physically and mentally. Here are some of the symptoms of serotonin deficiency:

  • Depression
  • Anxiety
  • Aggressive behavior/irritability
  • Impulsivity
  • Sleep problems- Fatigue
  • Appetite problems
    • Craving sweets/carbs
    • Weight gain
    • Nausea
  • Digestive Problems
  • Concentration problems
  • Addictive behaviors
  • Obsessive/compulsive behaviors/disorders
  • Social anxiety or panic disorders

Doctors and researchers alike have struggled to find direct links for how serotonin is related to these symptoms, as the functioning of serotonin in our body seems to be more multifaceted than early researchers believed. Still, mental health professionals often conceptualize their clients as potentially having serotonin deficiency when they present with a myriad of these symptoms. Serotonin deficiency is hard to diagnose, because there are not currently any concrete tests that confirm how much serotonin your body is producing. Instead, doctors and mental health professionals will discuss symptoms with their patients and make an educated guess that this may be part of the case and begin to treat them appropriately.

In terms of treatment, the main treatment involves a medication called a serotonin reuptake inhibitor (SSRI); SSRI’s don’t increase the amount of serotonin in the body, but instead they increase the availability for serotonin to bind to the body’s serotonin receptors, which makes it easier for the body to use the serotonin it is already developing more efficiently. SSRI’s are a common psychiatric medication prescribed for people who suffer from symptoms of anxiety and depression when therapy and other natural methods do not seem to be working as well as they should. In addition to psychiatric medication, there are numerous other ways that have been found to increase the efficiency of serotonin being transmitted through the body. Dietary changes such as increasing omega 3 fatty acids and taking L-tryptophan and vitamin D and B supplements have been seen to help with some of these symptoms as well. In addition, frequent activity and exercise, good sleep, and a good amount of sunshine/bright light have been seen to help improve a person’s symptoms related to serotonin deficiency.

If you believe you may be experiencing a serotonin deficiency, speaking to both a medical and mental health professional about your symptoms could help you figure out the best plan for getting back to feeling healthy and happy. Making small changes in diet, activity levels, and sleep patterns can help, but often what works best is doing these things in combination with seeking support from professionals who can make a plan to help. Therapy can also be a helpful way to process and explore all of the different symptoms related to mental health and has been shown in research to improve the efficacy of medication, if SSRI’s are being taken.

Shannon V. McHugh, PsyD

Dr. Shannon McHugh is a Licensed Clinical and Forensic Psychologist in Los Angeles, California. She specializes in assessment and treatment of children, adolescents, and adults who have developmental and social delays, behavioral difficulties, and those who have experienced traumatic events

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