Anti-depressants are mood-stabilizing drugs used to treat a variety of conditions, including moderate to severe depressive disorder, anxiety attacks and post-traumatic stress disorder. First discovered in the early 1950s, anti-depressants have become an effective tool in combating depression and other disorders. Anti-depressants were first discovered by accident when a drug called Iproniazid, originally developed to treat tuberculosis, was found to ease symptoms of depression. Although scientists are still not sure exactly what causes depression, it is believed that some neurotransmitters — the chemicals that pass messages between brain cells — greatly affect a person's mood. Anti-depressants work by increasing the activity of these neurotransmitters.
There are four main types of anti-depressants used today. The earliest mood-stabilizing drugs belonged to a group of medications known as monoamine oxidase inhibitors (MAOIs). MAOIs work by stopping the breakdown of monoamine neurotransmitters, thus increasing the amount of these chemicals present in the body. Typically prescribed for depression and social anxiety, MAOIs can cause very serious drug and food interactions. Due to their dangerous nature, these drugs are usually prescribed today only for patients who have not responded to other treatments.
After the discovery of MAOIs, scientists developed tricyclic anti-depressants (TCAs). TCAs cause fewer side effects than MAOIs and were therefore the preferred method of treatment for many years. TCAs are also effective for treating chronic pain such as neuralgia. However, they are dangerous in overdose and have largely been replaced by newer drugs.
Today, the most widely prescribed anti-depressants belong to a class known as selective serotonin reuptake inhibitors (SSRIs). Very basically, SSRIs work by keeping a larger amount of the neurotransmitter serotonin in the brain's receptor areas, allowing the brain to better utilize the serotonin. It is generally believed that serotonin directly influences mood, so by keeping a larger amount of this chemical in a place where the body can use it, patients may experience an improved mood.
The last major group of anti-depressants used today belong to the class of serotonin-norepinephrine reuptake inhibitors (SNRIs). SNRIs work more or less the same way as SSRIs, except that they affect the way the brain uses the neurotransmitter norepinephrine as well as serotonin. SSRIs and SNRIs are generally safer than MAOIs and TCAs, causing fewer side effects and drug interactions.
Some common side effects induced by anti-depressants include dry mouth, drowsiness, changes in appetite and increased feelings of depression and anxiety. However, many of these symptoms decrease after the body adjusts to the drug. Anti-depressants may also cause sexual side effects, such as decreased libido and erectile dysfunction.
Because depression and other affective disorders can be related to situational causes as well as chemical imbalances, anti-depressants are usually combined with psychotherapy in order to combat depression. As with any medication, it is important that patients only take anti-depressants under a doctor's supervision. When combined with therapy, mood-stabilizers have been shown to produce very effective results in depression sufferers.
How do Antidepressants Work?
There are several different types of antidepressants, each of which works in different ways. All of these medications are designed to affect certain chemicals or neurotransmitters in the brain that are responsible for mood, but different types affect one or more of these neurotransmitters differently. In general, antidepressants work by increasing the amount of neurotransmitters in the brain, usually by preventing them from being broken down or "recycled" in the body. How exactly this is accomplished, and how the changes in levels of neurotransmitters affect other aspects of brain chemistry, is still being investigated.
This type of medication is often prescribed to people suffering from depressive illness. The causes of depressive illness are not completely understood, but many researchers believe that neurotransmitters, including serotonin, norepinephrine, and dopamine, play a significant role. These chemicals, which are released from nerve cells in the brain, only have a short time to relay their message to another cell before enzymes destroy them or they are taken back up by the cell. This process is referred to as reuptake. Once reuptake occurs, the neurotransmitter stops having any effect on the brain.
Medications known as selective serotonin reuptake inhibitors (SSRIs) delay the reuptake of one of these neurotransmitters, serotonin, raising its levels in the brain. Higher levels of serotonin seem to help the brain send and receive messages more easily, which, in turn, improves mood. SSRIs are very popular because they seem to have the fewest side effects among such drugs. Additionally, those side effects tend to be mild to moderate and are transitory, usually disappearing after one to three weeks.
Tricyclic antidepressants (TCAs), work in the same manner as SSRIs, but affect the uptake of all three neurotransmitters associated with mood: serotonin, norepinephrine and dopamine. They do have more side effects, however, and can be dangerous if taken in high amounts. TCAs are not recommended to patients with heart trouble.
Monoamine oxidase inhibitors (MAOIs), an older class of antidepressants, increase levels of all three neurotransmitters by inhibiting an enzyme responsible for inactivating them. MAOIs also affect tyramine, a molecule linked to blood pressure; as a result, anyone taking MAOIs must stick to a very strict diet that forbids a variety of common foods like cheeses, yogurt, certain meats, bananas, and many more foods. Failure to do so can lead to a hypertensive crisis and may result in death. MAOIs also interact with many medications and are no longer widely prescribed.
Although these drugs are not addictive and can be taken in an ongoing regimen, they are normally prescribed for a four to six month period, with most people experiencing some benefit after two to four weeks of use, and full benefits at about four months. Patients are encouraged to seek other means of relief from their depression during this period, including exercise, a healthy diet, and "talk" therapy to work through any external cause for the depression.
Specific side effects vary among the different groups of antidepressants and should be discussed with a healthcare professional. Medications should not be mixed unless under the guidance of a medical professional. In some cases, depression can increase when patients first start taking the drugs, before they have a chance to work, and this has been linked to a higher risk of suicide in rare cases. For the majority of patients, however, these medications have played an important role in relieving depressive illness. They might also be prescribed to relieve anxiety, obsessive behavior, panic attacks and post-traumatic stress syndrome.