Dopamine is rarely prescribed as a medication for personal use. It is primarily used in emergency rooms, where it is given intravenously as a treatment of shock after heart attack or to speed up the heartbeat if the heartbeat is dangerously low or the heart is unable to pump enough blood into the body with each beat. It is also administered in cases of deadly infections and during open heart surgery. Many anti-anxiety and antidepressant medications increase the body's natural levels of dopamine, which can help alleviate anxiety and depression in some individuals.
Dopamine
As a naturally occurring chemical, dopamine functions as a neurotransmitter. Dopamine-producing neurons secrete the chemical into extracellular areas of the brain. The molecule is then able to bind to binding sites on other neurons and thereby enhance their activity. Dopamine is essential for memory, motivation and even for something as simple as movement. It is the low levels of dopamine in individuals with Parkinson's disease that cause the muscle disturbances characteristic of the disease. Dopamine is also a reward chemical, creating the feel-good feeling associated with fun and "rewarding" activities.
Anxiety
Anxiety is a complex condition in which the amygdala, the brain's main fear-processing center, is hyperactive. This causes the adrenal glands in the body to secrete excess stress chemicals, which can give rise to muscle tension, excessive sweating, increased heartbeat and a desire to escape. Low levels of the mood-regulator serotonin are the main cause of anxiety. In obsessive-compulsive disorder, low serotonin levels cause obsession and high dopamine levels cause compulsion. Low levels of dopamine usually leads to depression but can also lead to anxiety.
Dopamine as an Emergency Treatment of Heart Failure
When the heartbeat is slow or ineffective, the body and brain do not get enough oxygen. This can lead to organ failure and brain damage. Emergency room personnel sometimes choose to give dopamine intravenously as a temporary way of increasing oxygen supply. The treatment is most common when a patient has a failing aortic heart valve, the valve that opens to let oxygenated blood into the bloodstream and then closes to prevent it from drifting back. When the aortic heart valve is failing, some of the oxygenated blood floats back into the heart so that insufficient amounts of oxygen enter the bloodstream. Dopamine can rectify this by increasing the heartbeat.
Increasing Dopamine Levels as a Treatment of Anxiety
Third-generation antidepressant medications, such as venlafaxine, down-regulate the serotonin and norepinephrine transporters that transport serotonin and norepinephrine back into the cells. This increases the amounts of norepinephrine in the extracellular areas of the brain, which in turn leads to an increase of dopamine levels. When a serotonin, norepinephrine or dopamine imbalance is the cause of anxiety or depression, these medications can correct this chemical imbalance and alleviate the symptoms. Antidepressants, such as bupropion, which are most popular as an aid in quitting smoking, down-regulate only the norepinephrine transporter. This too increases extracellular levels of dopamine.
References
- "CNS Drugs"; Third-Generation Antidepressants: Do They Offer Advantages Over the SSRIs?; Olver J.S.; Burrows G.D.; Norman T.R.; December 2001
- The Merck Manual for Health Care Professionals: Dopamine
- Drugs.com: Dopamine Hydrochloride
- CancerNewsNetWork.org: Dopamine
- Mayo Clinic: Parkinson's Disease
- Mayo Clinic: Anxiety Disorders
