Antidepressant medications are used to treat more than depression. Some antidepressants are used to help you sleep; others treat anxiety; and some can be used to help relieve certain types of pain. Antidepressants are theorized to act on neurotransmitters in the brain - the chemicals that transmit nerve impulses between neurons (brain cells). In most cases the drugs act to either increase the amount of neurotransmitters at the synapse (the gap between neurons) or to keep these chemicals around longer.
The first antidepressant, iproniazid, was originally developed as a treatment for tuberculosis. It was widely prescribed in the late 1950s to treat depression. Iproniazid belonged to a class of medications known as monoamine oxidase inhibitors (MAOIs). This type of drug revolutionized the treatment of depression, but patients had to follow a strict diet to avoid dangerous side effects.
The MAOIs were followed by the tricyclic antidepressants. The first of these drugs, imipramine (Tofranil), was originally developed as a possible treatment for schizophrenia. It failed as a schizophrenia treatment, but succeeded as an antidepressant. Like most tricyclics, imipramine elevates mood and increases energy in many depressed patients.
In addition to treating depression, many of these medications have different uses. Tricyclic antidepressants also tend to be sedating; so triclycics such as amitriptyline (Elavil) and trazodone (Desyrel) are sometimes used as sleep medications (and even used to help treat chronic pain). Buspirone (Buspar) is a tricyclic that is actually used to treat anxiety rather than depression, while clomipramine (Anafranil) is a closely-related heterocyclic antidepressant that is approved for the treatment of obsessive-compulsive disorder (OCD).
Almost 30 years would pass before first the first SSRI (selective serotonin reuptake inhibitor), fluoxetine (Prozac) was approved in 1987. SSRIs are thought to act by increasing the amount of serotonin at the synapse (although competing theories explaining their antidepressant effect have emerged). Like the tricyclics, the SSRIs are being used for disorders other than depression. Fluoxetine itself is being marketed as Sarafem to women with PMS. This is one of the few times that a drug company has designated two names for the same drug. Wellbutrin and Zyban are also the same chemical - bupropion. Wellbutrin is marketed as an antidepressant and Zyban is marketed as an aid to stop smoking.
In addition to treating depression, antidepressants are probably most commonly used to treat anxiety. The antidepressant paroxitine (Paxil) has been FDA approved to treat generalized anxiety disorder and social phobia. Other antidepressants are also being studies as anxiety treatments, even if they have not been FDA approved. Forrest Labs, makers of the antidepressant citrilopram (Celexa) are in the final stages of researching escitalopram oxalate (a close relative of citrilopram) that they are marketing as Lexapro. They presented early research results at the 2002 Annual Meeting of the Anxiety Disorders Association of America that suggested that this new SSRI is effective in treating social anxiety disorder, generalized anxiety disorder, and panic disorder. It will be approved later this year to treat depression, but the manufacturer is hoping that physicians will prescribe it for anxiety as well.
The Internet has served as a power equalizer in health matters. Patients routinely go Online to lookup medications that they are prescribed; and they sometimes panic when they read that a certain medication is an antidepressant. "But I'm not depressed" they say, not realizing that there are other uses for these medications. If you are not sure why someone prescribed a medication for you - ask.