Serotonin syndrome occurs when a person takes drugs that cause excess levels of serotonin to accumulate in the body. Symptoms can include agitation, a dry mouth, dilated pupils, confusion, and more.

Though antidepressants are a common treatment for depression, psychiatrists still don’t have a clear understanding of how exactly they work. A new paper suggests that some explanations persist thanks ...

L-tryptophan is an essential amino acid that helps the body make proteins and certain brain-signaling chemicals. Your body changes L-tryptophan into a brain chemical called serotonin. Serotonin helps ...

Although serotonin is well known as a brain neurotransmitter, it is estimated that 90 percent of the body's serotonin is made in the digestive tract. In fact, altered levels of this peripheral ...

Serotonin is a neurotransmitter, or chemical messenger, that controls and stabilizes your mood and functions in your brain. What might surprise you is that it’s also crucial to the functions of your ...

Researchers have discovered that antidepressant drugs such as Prozac not only affect levels of the neurotransmitter serotonin in the brain, but also "hijack" dopamine signaling as well--causing it to ...

Fluctuations of serotonin levels in the brain, which often occur when someone hasn't eaten or is stressed, affects brain regions that enable people to regulate anger, new research has shown.

Serotonin is known to regulate digestion at multiple levels within the human gastrointestinal, and up to 95% of the mood-regulating hormone is released into the gut by certain intestinal cells. What's ...