Depression: Environmental Factors, Diagnosing, Antidepressant Drugs

by Food and Drug Administration (FDA)

(Page 2 of 3)

Environmental factors, however, may also play a role in depression. When combined with a biochemical or genetic predisposition, life stressors (such as relationship problems, financial difficulties, death of a loved one, or medical illness) may cause the disease to manifest itself.

John (not his real name), 25, was diagnosed with depression for the first time last year when he and his girlfriend ended their three-year relationship. "I couldn't do anything because I was totally absorbed with the whole break-up issue," he says. "It was impossible for me to sleep, and I would wake up at 3 or 4 in the morning and literally shake. And when it was time to wake up, I just couldn't get out of bed."

In addition, substance abuse and side effects from prescription medication may also lead to a depressive episode. And research shows that people battling serious medical conditions are especially prone to depression. According to the U.S. Department of Health and Human Services, those who have had a heart attack, for example, have a 40 percent chance of being depressed.

Seasonal affective disorder, often called "SAD," is a striking example of an environmental factor playing a major role in depression. SAD usually starts in late fall, with the decrease in daylight hours and ends in spring when the days get longer.

The symptoms of SAD, which include energy loss, increased anxiety, oversleeping, and overeating, may result from a change in the balance of brain chemicals associated with decreased sunlight. The exact reason for the association between light and mood is unknown, but research suggests a connection with the sleep cycle. Several studies have suggested that light therapy, which involves daily exposure to bright fluorescent light, may be an effective treatment for SAD.

Diagnosing the Disease

Medical professionals generally base a diagnosis of depressive disorder on the presence of certain symptoms listed in the American Psychiatric Association's Diagnostic and Statistical Manual. The DSM (presently in the fourth edition) lists the following symptoms for depression:

• depressed mood
• loss of interest or pleasure in almost all activities
• changes in appetite or weight
• disturbed sleep
• slowed or restless movements
• fatigue, loss of energy
• feelings of worthlessness or excessive guilt
• trouble in thinking, concentrating, or making decisions
• recurrent thoughts of death or suicide.

The diagnosis depends on the number, severity and duration of these symptoms.

Even with this list of symptoms, diagnosing depression is not simple. According to the National Alliance for the Mentally Ill, it takes an average of eight years from the onset of depression to get a proper diagnosis.

In making a diagnosis, a health professional should also consider the patient's medical history, the findings of a complete physical exam, and laboratory tests to rule out the possibility of depressive symptoms resulting from another medical problem.

The symptoms of the depressive part of bipolar disorder are the same as those expressed in major (unipolar) depression. Because of the similarities in symptoms and the fact that manic episodes usually don't appear until the mid-20s, some people with bipolar disorder may mistakenly be diagnosed with unipolar depression. This may lead to improper treatment because antidepressants carry the risk of triggering a manic episode. (For information about treating bipolar disorder, see "Evening Out the Ups and Downs of Manic-Depressive Illness" in the June 1996 FDA Consumer.)

Antidepressant Drugs

One major approach for treating depression is the use of antidepressant medications. The older antidepressants include tricyclic antidepressants such as Tofranil (imipramine) and monoamine oxidase inhibitors such as Nardil (phenelzine). Antidepressants approved more recently include the selective serotonin reuptake inhibitors Prozac, Paxil and Zoloft, and the other newer antidepressants Wellbutrin, Effexor, Serzone, and Remeron.

The effects of antidepressants on the brain are not fully understood, but there is substantial evidence that they somehow restore the brain's chemical balance. These medications usually can control depressive symptoms in four to eight weeks, but many patients remain on antidepressants for six months to a year following a major depressive episode to avoid relapse.

Different drugs work for different people, and it is difficult to predict which people will respond to which drug or who will experience side effects. So it may take more than one try to find the appropriate medication.

Since the mid-1950s, tricyclic antidepressants have been the standard against which other antidepressants have been measured. Monoamine oxidase inhibitors were discovered around the same time as tricyclic antidepressants, but were prescribed less because, if mixed with certain foods or medications, the drugs sometimes resulted in a fatal rise in blood pressure.

Laughren describes Prozac as the "first of a new type of more selective antidepressants." The older antidepressants had unpleasant and sometimes dangerous side effects, such as insomnia, weight gain, blurred vision, sexual impairment, heart palpitations, dry mouth, and constipation. Prozac, other selective serotonin reuptake inhibitors, and other recently approved antidepressants have had generally safer side effect profiles.

A recent study funded by NIMH suggested that Prozac may be as effective in treating children and teens as adults, but the drug is not yet approved by FDA for use in this population.

Other types of therapy, such as natural substances extracted from plants, are currently being studied. Although not approved by FDA, some people believe St. John's wort, for example, is extremely helpful in alleviating their depressive symptoms. (See "An Herbal Alternative?")

When people are unresponsive to antidepressant medications or can't take them because of their age or health problems, electroconvulsive therapy (ECT), or "shock therapy," can offer a lifesaving alternative. Like antidepressants, ECT is believed to affect the chemical balance of the brain's neurotransmitters.

Before ECT, the patient is given anesthesia and a muscle relaxant to prevent injury or pain. Then electrodes are placed on the person's head, and a small amount of electricity is applied. This procedure is usually done three times a week until the patient improves. Some patients may experience a temporary loss of short-term memory.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.