Research about the brain, nervous system, and psychological or mood disorders has provided information about neurotransmitters and their influences. These transmitters are an endogenous chemical, which means they are made inside the body. There are many neurotransmitters that are made by different cells, but there are three neurotransmitters that are known to affect mental functions: dopamine, norepinephrine, and serotonin. Each of these chemicals influences depression in different manners, whether alone or together, and have roles in how mood, pleasure, and sleep are regulated.
Neurotransmitters are message chemicals. They have the main function of carrying messages between cells. Neurotransmitters travel from one neuron, down the synapse, and to the receptor of a neighboring neuron. There are different types of cells in the body, and each type of cell produces different neurotransmitters. A link in the role of neurotransmitters in depression has been found through research studies.
Dopamine is one possible contributor to the role of neurotransmitters in depression. This neurotransmitter affects mood and pleasure. Increases in dopamine levels lead to prolonged exposure. Studies have shown that receptors in the brain caused regulatory proteins to become inactive, resulting in a depressed state when a person is exposed to stress. A reduction in dopamine levels can also cause the development of depression.
Another known contributor to the role of neurotransmitters in depression is norepinephrine. This neurotransmitter regulates the stress response. While low levels of norepinephrine can cause depression, not every person who suffers from depression will have low levels. Some people will have a decrease in norepinephrine, but not enough to lead to depression. In these cases, serotonin has an effect on norepinephrine levels.
As another influence on the role of neurotransmitters in depression, serotonin can contribute to depression in two ways. On its own, decreases in serotonin levels can cause severe depression. In some cases, suicidal tendencies have been caused by a drop in serotonin levels. Serotonin can also influence norepinephrine levels. Some patients will have a drop in serotonin that also causes a drop in norepinephrine levels.
Neurotransmitters are typically supposed to rely on each other to maintain a balance in the body. Unfortunately, a problem with one neurotransmitter can play a large role in neurotransmitters in depression cases. A chain reaction occurs. For many people who suffer from depression, multiple neurotransmitters are causing symptoms. As a result of research, doctors now know why some people do not respond to medications that target only one neurotransmitter.