Serotonin is important for initiating sleep and adapting to stressful situations. It also gives us an ability to cope with depression. However, sometimes serotonin does just the opposite to us. It causes insomnia and/or depression. This seems to be the case in fibromyalgia. A mishandling of serotonin plays a part in creating the insomnia, fatigue, fibro-fog, pain and depression of fibromyalgia.
Some of the earlier investigations into fibromyalgia indicated that the blood’s serum levels of serotonin might be low. More recently, a study using a different method of investigation showed that most people with fibromyalgia have very high levels of serotonin present in the blood’s plasma rich platelets, although there were also a few people who had very little serotonin. [2] So which is it? Too much or too little? Or is the most important thing how the serotonin is being used?
The real problem is the misuse of serotonin. In many ways, the body of someone with fibromyalgia acts like it has too much serotonin. There are many observations that are very consistent with an excessive serotonin-like influence.
1. Central Hypothyroidism. Chronic pain or stress elevates free serotonin in the brain and this induces central hypothyroidism. [3] (Hypothyroidism means the body doesn’t have enough thyroid hormone. This causes fatigue, mood alterations, and poor immunity. “Central” hypothyroidism means that the brain isn’t telling the thyroid gland to create and release thyroid hormone.) Central hypothyroidism occurs in about half the people who have fibromyalgia. This suggests that free serotonin might be too high in parts of the brain.
2. Hormone Dysregulation. Serotonin promotes the formation of corticotropin-releasing hormone (CRH). An activation of the CRH neurons would disturb regulation of many hormones in exactly the same manner as observed in fibromyalgia. [3] (Other types of stressors, such as infection and pain also increase CRH.)
3. Disrupted Non-REM Sleep. Serotonin promotes the formation of CRH, and CRH increases spontaneous waking and reduces Non-REM sleep. [4] Those with fibromyalgia experience poor Non-REM sleep. (REM means rapid-eye-movement.) In fact, just a lack of non-REM stage 4 sleep may cause muscle pain and mood changes similar to fibromyalgia.
4. Elevated Substance P. Substance P is elevated in the spinal fluid of those with fibromyalgia. This heightens the sensitivity to pain. Since serotonin increases substance P, this is another indication that perhaps free serotonin is elevated.
5. Defective Mitochondria. In fibromyalgia, defects in the cells’ mitochondria have been observed. When cells are exposed to free serotonin, it poisons the cells’ mitochondria. [5] This disrupts energy production and causes fatigue. (“Free” serotonin means that the serotonin is not contained within cells. It is surrounding the cells. When cells are left to soak in a bath of serotonin, it damages their mitochondria.)
6. Elevated cytokine IL-6. An immune system cytokine called IL-6 is elevated in fibromyalgia. IL-6 decreases REM sleep, causes fatigue, and interferes with concentration in humans. [6, 7] Free serotonin and substance P both may increase this IL-6 cytokine. [6, 8 ] This is yet another hint that free serotonin might be high.
7. Blood Coagulation and Fibrin. Increased blood clotting and fibrin formation has been observed in fibromyalgia. Free serotonin promotes this.
8. Poor Microcirculation. This interferes with oxygen getting to the cells. Free serotonin contributes to poor microcirculation by increasing fibrin formation and constricting blood flow. (When you are cut, some of the cells release serotonin. This constricts blood vessels and helps form a clot. This is an important function because the bleeding from a cut needs to be stopped. The released serotonin helps the body do this. However, you don’t want serotonin to be released when it isn’t needed. This would be a harmful misuse of serotonin.)
All of the above is consistent with a high presence of free serotonin in parts of the brain and possibly elsewhere in the body.
Serotonin is important for initiating sleep and adapting to stressful situations. It also gives us an ability to cope with depression. However, sometimes serotonin does just the opposite to us. It causes insomnia and/or depression. This seems to be the case in fibromyalgia. A mishandling of serotonin plays a part in creating the insomnia, fatigue, fibro-fog, pain and depression of fibromyalgia.
Some of the earlier investigations into fibromyalgia indicated that the blood’s serum levels of serotonin might be low. More recently, a study using a different method of investigation showed that most people with fibromyalgia have very high levels of serotonin present in the blood’s plasma rich platelets, although there were also a few people who had very little serotonin. [2] So which is it? Too much or too little? Or is the most important thing how the serotonin is being used?
The real problem is the misuse of serotonin. In many ways, the body of someone with fibromyalgia acts like it has too much serotonin. There are many observations that are very consistent with an excessive serotonin-like influence.
1. Central Hypothyroidism. Chronic pain or stress elevates free serotonin in the brain and this induces central hypothyroidism. [3] (Hypothyroidism means the body doesn’t have enough thyroid hormone. This causes fatigue, mood alterations, and poor immunity. “Central” hypothyroidism means that the brain isn’t telling the thyroid gland to create and release thyroid hormone.) Central hypothyroidism occurs in about half the people who have fibromyalgia. This suggests that free serotonin might be too high in parts of the brain.
2. Hormone Dysregulation. Serotonin promotes the formation of corticotropin-releasing hormone (CRH). An activation of the CRH neurons would disturb regulation of many hormones in exactly the same manner as observed in fibromyalgia. [3] (Other types of stressors, such as infection and pain also increase CRH.)
3. Disrupted Non-REM Sleep. Serotonin promotes the formation of CRH, and CRH increases spontaneous waking and reduces Non-REM sleep. [4] Those with fibromyalgia experience poor Non-REM sleep. (REM means rapid-eye-movement.) In fact, just a lack of non-REM stage 4 sleep may cause muscle pain and mood changes similar to fibromyalgia.
4. Elevated Substance P. Substance P is elevated in the spinal fluid of those with fibromyalgia. This heightens the sensitivity to pain. Since serotonin increases substance P, this is another indication that perhaps free serotonin is elevated.
5. Defective Mitochondria. In fibromyalgia, defects in the cells’ mitochondria have been observed. When cells are exposed to free serotonin, it poisons the cells’ mitochondria. [5] This disrupts energy production and causes fatigue. (“Free” serotonin means that the serotonin is not contained within cells. It is surrounding the cells. When cells are left to soak in a bath of serotonin, it damages their mitochondria.)
6. Elevated cytokine IL-6. An immune system cytokine called IL-6 is elevated in fibromyalgia. IL-6 decreases REM sleep, causes fatigue, and interferes with concentration in humans. [6, 7] Free serotonin and substance P both may increase this IL-6 cytokine. [6, 8 ] This is yet another hint that free serotonin might be high.
7. Blood Coagulation and Fibrin. Increased blood clotting and fibrin formation has been observed in fibromyalgia. Free serotonin promotes this.
8. Poor Microcirculation. This interferes with oxygen getting to the cells. Free serotonin contributes to poor microcirculation by increasing fibrin formation and constricting blood flow. (When you are cut, some of the cells release serotonin. This constricts blood vessels and helps form a clot. This is an important function because the bleeding from a cut needs to be stopped. The released serotonin helps the body do this. However, you don’t want serotonin to be released when it isn’t needed. This would be a harmful misuse of serotonin.)
All of the above is consistent with a high presence of free serotonin in parts of the brain and possibly elsewhere in the body.