Serotonin, a neurotransmitter, was first isolated in 1933. It has been identified as a major regulator of organic processes in the body that are responsible for sleep, sexuality, body temperature and memory. Although serotonin is produced in the Central Nervous System (CNS) as well as the gastrointestinal tract, its role as a neurotransmitter in the brain has been studied the most. Serotonin has been named in psychiatric disorders, including depression, obsessive-compulsive disorder, anorexia, bulimia, phobias and anxiety. The amount of available serotonin has wide ranging effects on brain activity.
Although the human body is capable of bearing much more than we normally believe, there is still a limit to what the body can tolerate. Similarly, the brain too has a tolerance level. Stress takes its toll on available serotonin in the brain and ultimately, on the overall emotional health of a person. Prolonged stressful environment or unresolved grief leads to using more serotonin than is normally replaced.
Symptoms of low serotonin in the body progress along with the rate of depletion. Low levels of serotonin leads to problems with attention, memory and concentration. There is a general lack of sense or direction and a difficulty in organizing routine responsibilities. As serotonin levels drop further, it leads to depressive feelings, lack of sleep and moderate depression. Humans can live with moderate depression for years as they get used to the symptoms associated with it. Sleep deprivation, for example, is compensated with alcohol or sleeping pills. Over a period of time, it becomes a way of life in such a manner that people do not realize that there is a component of depression in their lives.
Extremely low levels of serotonin, however, are difficult to ignore. Severe symptoms start to manifest themselves and very low levels of serotonin in the brain have a serious effect on the manner in which one thinks and the speed of the processing. Very low levels of serotonin affect the regulation of body’s functions negatively. The speed of thoughts becomes uncontrollable and lead to emotional numbness. Definitive symptoms associated with clinical depression, bipolar disease and obsessive compulsive disorders start showing with increased intensity. Short-term memory decreases while long-term memory increases. The mind keeps on reliving torturous events that occurred decades ago.
As a regulator of metabolism, low serotonin affects body temperature and also leads to cramps, bowel problems, pains and sensations of being smothered. Added to this, the racing and torturous thoughts lead the patient to a condition where even mild symptoms tend to get associated with terminal diseases.
The brain’s chemistry is affected by a variety of conditions. Constant stress and unresolved grief along with hypertension, high levels of cholesterol and fluctuating blood sugar beyond healthy levels are among the major causes of serotonin depletion. Extremely high levels, although a rare condition known as serotonin syndrome, can have toxic and potentially fatal effects. It is caused essentially by a combination of antidepressants like SSRIs and MOAIs.