Taken from WEBMD:
1. What is serotonin?
Serotonin is as a neurotransmitter, a type of chemical that helps relay signals from one area of the brain to another. Serotonin is manufactured in the brain, but the majority of it is found in the digestive tract and in blood platelets.
2. How is serotonin made?
Serotonin is made via a biochemical conversion process. A protein called Tryptophan is the starting material and combines with an enzyme - tryptophan hydroxylase - which forms 5-hydroxytryptamine, otherwise known as serotonin.
3. What role does serotonin play in our health?
Serotonin helps to relay messages in the brain. It is believed to influence a variety of psychological and other body functions. Most of our brain cells are influenced one way or another by serotonin.
In terms of our body function, serotonin can also affect the functioning of our cardiovascular system, muscles, and various elements in the endocrine system.
4. What is the link between serotonin and depression?
An imbalance in serotonin levels may influence mood in a way that leads to depression.
One theory about how depression develops centers on the regeneration of brain cells -- a process that some believe is mediated by serotonin, and ongoing throughout our lives. According to Princeton neuroscientist Barry Jacobs, PhD, depression may occur when there is a suppression of new brain cells and that stress is the most important precipitator of depression. At the time of writing there is no way to measure the levels of serotonin in the living brain. Blood levels of serotonin are measurable -- and have been shown to be lower in people who suffer from depression.
5. Can diet influence our supply of serotonin?
There are foods and some nutrients that can increase levels of tryptophan, the amino acid from which serotonin is made.
6. Can exercise boost serotonin levels?
Exercise can do a lot to improve your mood -- and across the board, studies have shown that regular exercise can be as effective a treatment for depression as antidepressant medication or psychotherapy.
7. Do men and women have the same amount of serotonin -- and does it act the same way in their brain and body?
Studies show that men do have slightly more serotonin than women, but the difference is thought to be negligible.
8. Since both dementia and Alzheimer's disease are brain-related conditions, does serotonin play a role in either problem?
In much the same way that we lose bone mass as we age, some researchers believe that the activity of neurotransmitters also slows down as part of the aging process. In one international study published in 2006, doctors from several research centers around the world noted a serotonin deficiency in brains of deceased Alzheimer's patients.
9. What is serotonin syndrome -- and is it common or dangerous?
SSRI antidepressants are generally considered safe. However, a rare side effect of SSRIs called serotonin syndrome can occur when levels of this neurochemical in the brain rise too high. It happens most often when two or more drugs that affect serotonin levels are used simultaneously. For example, if you are taking a category of migraine medicines called triptans, at the same time you are taking an SSRI drug for depression, the end result can be a serotonin overload.
