There are several types of antidepressant medications used to treat depressive disorders. These include newer medications�chiefly the selective serotonin reuptake inhibitors (SSRIs)�the tricyclics, and the monoamine oxidase inhibitors (MAOIs). The SSRIs�and other newer medications that affect neurotransmitters such as dopamine or norepinephrine�generally have fewer side effects than tricyclics. Sometimes the doctor will try a variety of antidepressants before finding the most effective medication or combination of medications. Sometimes the dosage must be increased to be effective. Although some improvements may be seen in the first few weeks, antidepressant medications must be taken regularly for 3 to 4 weeks (in some cases, as many as 8 weeks) before the full therapeutic effect occurs.
Patients often are tempted to stop medication too soon. They may feel better and think they no longer need the medication. Or they may think the medication isn’t helping at all. It is important to keep taking medication until it has a chance to work, though side effects (see section on Side Effects on page 13) may appear before antidepressant activity does. Once the individual is feeling better, it is important to continue the medication for at least 4 to 9 months to prevent a recurrence of the depression. Some medications must be stopped gradually to give the body time to adjust. Never stop taking an antidepressant without consulting the doctor for instructions on how to safely discontinue the medication. For individuals with bipolar disorder or chronic major depression, medication may have to be maintained indefinitely.
Antidepressant drugs are not habit-forming. However, as is the case with any type of medication prescribed for more than a few days, antidepressants have to be carefully monitored to see if the correct dosage is being given. The doctor will check the dosage and its effectiveness regularly.
For the small number of people for whom MAO inhibitors are the best treatment, it is necessary to avoid certain foods that contain high levels of tyramine, such as many cheeses, wines, and pickles, as well as medications such as decongestants. The interaction of tyramine with MAOIs can bring on a hypertensive crisis, a sharp increase in blood pressure that can lead to a stroke. The doctor should furnish a complete list of prohibited foods that the patient should carry at all times. Other forms of antidepressants require no food restrictions.
Medications of any kind�prescribed, over-the counter, or borrowed�should never be mixed without consulting the doctor. Other health professionals who may prescribe a drug�such as a dentist or other medical specialist�should be told of the medications the patient is taking. Some drugs, although safe when taken alone can, if taken with others, cause severe and dangerous side effects. Some drugs, like alcohol or street drugs, may reduce the effectiveness of antidepressants and should be avoided. This includes wine, beer, and hard liquor. Some people who have not had a problem with alcohol use may be permitted by their doctor to use a modest amount of alcohol while taking one of the newer antidepressants.
Antianxiety drugs or sedatives are not antidepressants. They are sometimes prescribed along with antidepressants; however, they are not effective when taken alone for a depressive disorder. Stimulants, such as amphetamines, are not effective antidepressants, but they are used occasionally under close supervision in medically ill depressed patients.
Questions about any antidepressant prescribed, or problems that may be related to the medication, should be discussed with the doctor.
Lithium has for many years been the treatment of choice for bipolar disorder, as it can be effective in smoothing out the mood swings common to this disorder. Its use must be carefully monitored, as the range between an effective dose and a toxic one is small. If a person has preexisting thyroid, kidney, or heart disorders or epilepsy, lithium may not be recommended. Fortunately, other medications have been found to be of benefit in controlling mood swings. Among these are two mood-stabilizing anticonvulsants, carbamazepine (Tegretol®) and valproate (Depakote®). Both of these medications have gained wide acceptance in clinical practice, and valproate has been approved by the Food and Drug Administration for first-line treatment of acute mania. Other anticonvulsants that are being used now include lamotrigine (Lamictal®) and gabapentin (Neurontin®): their role in the treatment hierarchy of bipolar disorder remains under study.
Most people who have bipolar disorder take more than one medication including, along with lithium and/or an anticonvulsant, a medication for accompanying agitation, anxiety, depression, or insomnia. Finding the best possible combination of these medications is of utmost importance to the patient and requires close monitoring by the physician.
Antidepressants may cause mild and, usually, temporary side effects (sometimes referred to as adverse effects) in some people. Typically these are annoying, but not serious. However, any unusual reactions or side effects or those that interfere with functioning should be reported to the doctor immediately. The most common side effects of tricyclic antidepressants, and ways to deal with them, are:
- Dry mouth�it is helpful to drink sips of water; chew sugarless gum; clean teeth daily.
- Constipation�bran cereals, prunes, fruit, and vegetables should be in the diet.
- Bladder problems�emptying the bladder may be troublesome, and the urine stream may not be as strong as usual; the doctor should be notified if there is marked difficulty or pain.
- Sexual problems�sexual functioning may change; if worrisome, it should be discussed with the doctor.
- Blurred vision�this will pass soon and will not usually necessitate new glasses.
- Dizziness�rising from the bed or chair slowly is helpful.
- Drowsiness as a daytime problem�this usually passes soon. A person feeling drowsy or sedated should not drive or operate heavy equipment. The more sedating antidepressants are generally taken at bedtime to help sleep and minimize daytime drowsiness.
The newer antidepressants have different types of side effects:
- Headache�this will usually go away.
- Nausea�this is also temporary, but even when it occurs, it is transient after each dose.
- Nervousness and insomnia (trouble falling asleep or waking often during the night)�these may occur during the first few weeks; dosage reductions or time will usually resolve them.
- Agitation (feeling jittery)�if this happens for the first time after the drug is taken and is more than transient, the doctor should be notified.
- Sexual problems�the doctor should be consulted if the problem is persistent or worrisome.
In the past few years, much interest has risen in the use of herbs in the treatment of both depression and anxiety. St. John’s wort (Hypericum perforatum), an herb used extensively in the treatment of mild to moderate depression in Europe, has recently aroused interest in the United States. St. John’s wort, an attractive bushy, low-growing plant covered with yellow flowers in summer, has been used for centuries in many folk and herbal remedies. Today in Germany, Hypericum is used in the treatment of depression more than any other antidepressant. However, the scientific studies that have been conducted on its use have been short-term and have used several different doses.
Because of the widespread interest in St. John’s wort, the National Institutes of Health (NIH) conducted a 3-year study, sponsored by three NIH components�the National Institute of Mental Health, the National Center for Complementary and Alternative Medicine, and the Office of Dietary Supplements. The study was designed to include 336 patients with major depression of moderate severity, randomly assigned to an 8-week trial with one-third of patients receiving a uniform dose of St. John’s wort, another third sertraline, a selective serotonin reuptake inhibitor (SSRI) commonly prescribed for depression, and the final third a placebo (a pill that looks exactly like the SSRI and the St. John’s wort, but has no active ingredients). The study participants who responded positively were followed for an additional 18 weeks. At the end of the first phase of the study, participants were measured on two scales, one for depression and one for overall functioning. There was no significant difference in rate of response for depression, but the scale for overall functioning was better for the antidepressant than for either St. John’s wort or placebo. While this study did not support the use of St. John’s wort in the treatment of major depression, ongoing NIH-supported research is examining a possible role for St. John’s wort in the treatment of milder forms of depression.
The Food and Drug Administration issued a Public Health Advisory on February 10, 2000. It stated that St. John’s wort appears to affect an important metabolic pathway that is used by many drugs prescribed to treat conditions such as AIDS, heart disease, depression, seizures, certain cancers, and rejection of transplants. Therefore, health care providers should alert their patients about these potential drug interactions.
Some other herbal supplements frequently used that have not been evaluated in large-scale clinical trials are ephedra, gingko biloba, echinacea, and ginseng. Any herbal supplement should be taken only after consultation with the doctor or other health care provider.