Neurotransmitters
It's impossible to understand how antidepressants work without a clear understanding of the functions of neurotransmitters. Neurotransmitters are chemicals that are released in the brain. They enable impulses from one nerve cell to pass to another nerve cell. Serotonin and norepinephrine, also called monoamines, are neurotransmitters that are responsible for controlling mood. Decreased production of these neurotransmitters has been linked to depression. Different types of antidepressants work in different ways to either slow down the removal or increase the production of serotonin.
Monoamine Oxidase Inhibitors
Monoamine oxidase inhibitors (MAOIs) are enzymes that break down monoamines. MAOIs, as their name implies, can inhibit this enzymatic action, which results in increased availability of serotonin and norepinephrine. Nardol, Parnate and Eldepryl are examples of MAOIs.
Selective Serotonin Reuptake Inhibitors
Scientists are unclear about how selective serotonin reuptake inhibitors (SSRIs) relieve the symptoms of depression. It has been speculated that these depression medications block the brain's reabsorption, or the reuptake, of serotonin, thereby leaving more available. These drugs are called selective because they only work on the serotonin. Lexapro, Zoloft, Paxil, Prozac and Celexa are common examples of selective serotonin reuptake inhibitors. Their effect will differ from patient to patient, and is often dependent on the way that the patient's serotonin reuptake receptor function works.
Norepinephrine and Dopamine Reuptake Inhibitors
Dopamine, like serotonin, is another one of the brain's "feel good" neurotransmitters. Scientists call it the reward chemical, because it is released in rewarding activities such as eating and making love. Buproprion is an antidepressant that has been classified as a norepinephrine and dopamine reuptake inhibitor. It works to inhibit the reuptake of these chemicals.
