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 However, they are dangerous in overdose and have largely been replaced by newer drugs.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.