Serotonin is one of dozens of neurotransmitters and is found in body tissues including the brain, blood, and the mucous membranes lining the stomach and digestive tract.
In the past decade, research studies of serotonin have found that it plays an essential role in the regulation of sleep, appetite, temperature, blood vessel tone, secretion of certain hormones and in the perception of pain, thereby affecting a wide range of conditions, such as migraine headaches, depression and sleep disturbances.
Recent studies have shown that imbalances in serotonin levels trigger depression. Doctors often treat patients with serotonin reuptake inhibitors (e.g. Prozac) because these medications can help to regulate serotonin levels. It is the role that serotonin plays in depression that perhaps is of most interest. People with depression have measurable 'imbalances' in the brain's neurotransmitters; low levels of serotonin are believed to play a critical role. If an episode of depression causes a change in your serotonin level, this can have an effect on your pain threshold too. Because serotonin helps keep 'pain gates' closed, a lack of it can make you feel more pain. Serotonin also helps with sleep, which explains the sleep disturbance encountered by those with depression.
It has been shown that certain brainwave frequencies in the theta range can help to balance natural serotonin levels. The 70 minute downloadable serotonin isochiral music suite creates the exact theta brainwave frequencies required to balance serotonin levels.