Finding the best antidepressant for you can be a challenge. Don't be surprised if you have to try more than one drug before you find one that works well for you. Many doctors continue to rely on well established drugs known as tricyclic antidepressants. These drugs are often very effective in relieving depression, but they usually take some time two to six weeks to become fully effective. They may also have unpleasant side effects such as constipation, dry mouth, blurred vision, urinary retention and drowsiness, and they may be less safe for people with heart disease than some of the newer drugs. Even though these side effects diminish or disappear after a few weeks, many older people find them especially difficult to tolerate and they may stop taking the medication altogether.

Your doctor may recommend an older tricyclic antidepressant such as imipramine (Tofranil) and doxepin (Sinequan). Although these can work well, a newer group of tricyclics for example, nortriptyline (Aventyl) and desipramine (Norpramin) seem to be better tolerated, especially by older people. In recent years a new generation of antidepressant drugs known as SSRIs (selective serotonin reuptake inhibitors) has been developed. These drugs include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil) and fluoxamine (Luvox). They also take between two and six weeks to show some benefits, and while they are usually (but not always} as effective as the older drugs, they tend to have fewer or at least more tolerable side effects. This makes them ideal for many older people. If you take one of these drugs, you may experience some nausea, headaches or agitation, but such side effects may disappear. Even so, they should always be reported to your doctor.

Finding the right dosage is extremely important. If the dose is too low, the drug won't be effective; if it's too high, you may experience unpleasant side effects. Recent studies have shown that older people can )obtain relief with lower doses of antidepressant medication, so your doctor may adopt a "start low, go slow" approach. Because antidepressants start to work only when they reach what doctors call a "therapeutic level" in your body, it's vital that you give these drugs enough time to work. This can be difficult if you're experiencing side effects, but most doctors recommend that you try each medication for at least four weeks before giving up and switching to a different drug.

Most people have to remain on antidepressant medication for many months, even after they begin to feel better. How long you continue to take the drug depends on your general health, the severity of the depression and whether your depressions tend to recur. You should never stop taking antidepressants suddenly, since this can cause problems. Instead, your doctor will advise you to taper the dosage down gradually. If your symptoms recur, you may have to take antidepressant drugs indefinitely.