What Does Serotonin Do?
Serotonin is a neurotransmitter that can be found in the central nervous system, blood platelets, and digestive tract. Serotonin plays a role in:
Regulating moodInfluencing quality of sleepConsolidating memoriesRegulating appetiteInfluencing sexual desireAssisting with digestion and other bodily processes
Because it heavily impacts mood and other important functions, serotonin is targeted by antidepressants such as selective serotonin reuptake inhibitors (SSRIs), which increase the available levels of serotonin in the brain. SSRIs are considered to be first-line agents in the treatment of panic disorder, depression, obsessive compulsive disorder, and other anxiety disorders.
Why Is Serotonin Sometimes Toxic?
Serotonin syndrome, or serotonin toxicity, is a rare and potentially life-threatening condition caused by dangerously high levels of serotonin in the brain. It’s generally caused by taking two or more medications that raise serotonin levels in the central nervous system. Substances that may contribute to excess serotonin levels include:
Some types of antidepressants Triptan migraine medications Illicit drugs such as cocaine, lysergic acid diethylamide (LSD), amphetamines, and ecstasy Herbal supplements such as St. John’s wort, nutmeg, and ginseng Certain cold medications Some anti-nausea medications
SSRIs, serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, and monoamine oxidase inhibitors (MAOIs) are all classes of antidepressant medications that have been implicated in the development of serotonin syndrome. These antidepressants are often prescribed to treat depression and anxiety disorders, including panic disorder.
Signs of Too Much Serotonin
Individuals may begin to experience symptoms of serotonin toxicity if they take too much of a serotonin-increasing drug or take more than one. Symptoms of serotonin syndrome may include:
Confusion Increased reflexes Restlessness Hallucinations Extreme agitation Fluctuations in blood pressure Increased heart rate Nausea, vomiting, and diarrhea Fever Seizures Coma
Symptoms of serotonin syndrome can begin within minutes, a few hours, or up to 24 hours after taking or increasing the dose of a medication. Most individuals experiencing symptoms of serotonin syndrome will seek emergency treatment within six hours.
Serotonin and Anxiety
While SSRIs are sometimes prescribed to help treat anxiety, some research suggests that high levels of serotonin may be associated with anxiety disorders including social anxiety disorder and panic disorder. Studies suggest that an overactive serotonin system impacts the fear centers in the brain, which may lead to anxiety symptoms.
What to Do
Since serotonin syndrome can be potentially life-threatening, emergency medical treatment is necessary. Treatment often begins with the withdrawal of the medications causing the dangerously high levels of serotonin. However, some complications such as delirium, unstable heart rate, high blood pressure, and high temperature may persist longer. Supportive measures and interventions in a hospital setting may be necessary and include:
Heart rate and blood pressure control: Medications to decrease heart rate and blood pressure may be needed. On the other hand, medications may be given to raise blood pressure if it is too low. Temperature control: Fever may be treated with methods such as cooling blankets. Sedation: Benzodiazepines may be used to help control muscle rigidity and extreme agitation. Hydration: Intravenous fluids may be needed to address dehydration caused by high body temperature and sweating. Cyproheptadine: This antihistamine is sometimes used to block serotonin production in the body. It’s been shown to reduce the severity of symptoms associated with serotonin syndrome.
Prevention
To prevent serotonin syndrome, be sure to tell your doctor about all of the medications you are currently taking, including prescription drugs, over-the-counter medications, and supplements. If you’re taking a medication that impacts serotonin levels, talk to your doctor about your risk of developing serotonin syndrome. Seek immediate medical care if you’re taking a medication that affects serotonin levels and you develop any of the symptoms of serotonin syndrome.
A Word From Verywell
Keep in mind that even natural supplements can sometimes be dangerous, especially if they are combined with other medications that affect serotonin levels. If you are on any type of medication that impacts serotonin, you should always use caution and talk to your doctor before taking any other medication or substance.
