What Is Depression?

Depression is a disorder that affects your thoughts, moods, feelings, behavior and physical health. People used to think it was "all in your head" and that if you really tried, you could "pull yourself out of it." Doctors now know that depression is not a weakness, and you can't treat it on your own. It's a medical disorder with a biological or chemical basis.

Sometimes a stressful life event triggers depression. Other times depression seems to occur spontaneously, with no identifiable specific cause. Whatever the cause, depression is much more than grieving or a bout of the blues.

Depression may occur only once in a person's life. Often, however, it occurs as repeated episodes over a lifetime, with periods free of depression in between. Or it may be a chronic condition, requiring ongoing treatment over a lifetime. The disorder affects more than 18 million Americans of all ages and races.

Medications are available that are generally safe and effective, even for the most severe depression. With proper treatment, most people with serious depression improve, often within weeks, and can return to normal daily activities.

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Signs and Symptoms

Two hallmarks of depression — symptoms key to establishing the diagnosis — are:

• Loss of interest in normal daily activities. You lose interest in or pleasure from activities you used to enjoy. This is called anhedonia.
  
  
• Depressed mood. You feel sad, helpless and hopeless and may have crying spells.

In addition, for a doctor or other health professional to diagnose depression, most of the following signs and symptoms must also be present most of the day, nearly every day for at least 2 weeks:

• Sleep disturbances. Sleeping too much or having problems sleeping can be a sign you're depressed. Waking in the middle of the night or early in the morning and not being able to get back to sleep are typical.
  
  
• Impaired thinking or concentration. You may have trouble concentrating or making decisions and have problems with memory.
  
  
• Significant weight loss or gain. An increased or reduced appetite and an unexplained weight gain or loss of more than 5 percent of your normal weight can indicate depression.
  
  
• Agitation or slowing of body movements. You may seem restless, agitated, irritable and easily annoyed. Or you may seem to do everything in slow motion and answer questions slowly in a monotonous tone of voice.
  
  
• Fatigue. You feel weariness and lack of energy nearly every day. You may feel as tired in the morning as you did when you went to bed the night before.
  
  
• Low self-esteem. You feel worthless and have excessive guilt.
  
  
• Less interest in sex. If you were sexually active before developing depression, you may notice a dramatic decrease in your level of interest in having sexual relations.
  
  
• Thoughts of death. You have a persistent negative view of yourself, your situation and the future. You may have thoughts of death, dying or suicide.

Depression can also cause a wide variety of physical complaints, such as generalized itching, blurred vision, excessive sweating, dry mouth, gastrointestinal problems (indigestion, constipation and diarrhea), headache and backache.

Children, teens and older adults may react differently to depression. In these groups symptoms may take a different form or may be masked by other conditions.

Dry mouth Constipation Diarrhea

The main types of depression include:

• Major depression. This type of mood disturbance lasts more than 2 weeks. Symptoms may include overwhelming feelings of sadness and grief, loss of interest or pleasure in activities you usually enjoy, and feelings of worthlessness or guilt. This type of depression may result in poor sleep, severe fatigue, difficulty concentrating, change in appetite and suicide.
  
  
• Dysthymia. Dysthymia (dis-THI-me-uh) is a less severe but a more continuous form of depression. It lasts for at least 2 years and often more than 5 years. Signs and symptoms usually aren't disabling, and periods of dysthymia can alternate with short periods of feeling normal. Having dysthymia places you at an increased risk of major depression.
  
  
• Adjustment disorders. If a loved one dies, you lose your job or you receive a diagnosis of cancer, it's perfectly normal to feel tense, sad, overwhelmed or angry. Eventually, most people come to terms with the lasting consequences of life stresses, but some don't. This is what's known as an adjustment disorder — when your response to a stressful event or situation causes signs and symptoms of depression. Some people develop an adjustment disorder in response to a single event. In others, it stems from a combination of stressors. Adjustment disorders can be acute — lasting less than 6 months — or chronic — lasting longer. Doctors classify adjustment disorders based on the primary signs and symptoms of depression or anxiety.
  
  
• Bipolar disorder. Having recurrent episodes of depression and elation (mania) is characteristic of bipolar disorder. Because this condition involves emotions at both extremes (poles), it's called bipolar disorder or manic-depressive disorder. Mania affects your judgment, causing you to make unwise decisions. Some people have bursts of increased creativity and productivity during the manic phase. The number of episodes at either extreme may not be equal. Some people may have several episodes of depression before having another manic phase, or vice versa.
  
  
• Seasonal affective disorder. Seasonal affective disorder (SAD) is a pattern of depression related to changes in seasons and a lack of exposure to sunlight. It may cause headaches, irritability and a low energy level.

Many people with depression have symptoms of anxiety as well. Anxiety that develops after age 40 is often related to depression rather than being an independent problem.

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Causes

There's no single cause for depression. The illness often runs in families. Experts believe a genetic vulnerability combined with environmental factors, such as stress or physical illness, may trigger an imbalance in brain chemicals called neurotransmitters, resulting in depression. Imbalances in three neurotransmitters — serotonin, norepinephrine and dopamine — seem to be linked to depression.

Scientists don't fully understand how imbalances in neurotransmitters cause signs and symptoms of depression. It's not certain whether changes in neurotransmitters are a cause or a result of depression.


Here are factors that contribute to depression:

• Heredity. Researchers have identified several genes that may be involved in bipolar disorder, and they're looking for genes linked to other types of depression. But not everyone with a family history of depression develops the disorder.
  
  
• Stress. Stressful life events, particularly a loss or threatened loss of a loved one or a job, can trigger depression.
  
  
• Medications. Long-term use of certain medications, such as some drugs used to control high blood pressure, sleeping pills or, occasionally, birth control pills, may cause symptoms of depression in some people.
  
  
• Illnesses. Having a chronic illness, such as heart disease, stroke, diabetes, cancer or Alzheimer's disease, puts you at higher risk of developing depression. Studies reveal an as-yet-unexplained link between depression and heart disease. Depression occurs in up to half the people who've had heart attacks. Left untreated, depression may put you at a higher risk of death in the early years after a heart attack. Having an underactive thyroid (hypothyroidism) — even mild hypothyroidism — also can cause depression.
  
  
• Personality. Certain personality traits, such as having low self-esteem and being overly dependent, self-critical, pessimistic and easily overwhelmed by stress, can make you more vulnerable to depression.
  
  
• Postpartum depression. It's common for mothers to feel a mild form of distress that usually occurs a few days to weeks after giving birth. During this time you may have feelings of sadness, anger, anxiety, irritability and incompetence. A more severe form of the baby blues, called postpartum depression, affects up to 25 percent of new mothers.
  
  
• Alcohol, nicotine and drug abuse. Experts once thought that people with depression used alcohol, nicotine and mood-altering drugs as a way to ease depression. But studies show that using these substances may actually contribute to depression and anxiety disorders.
  
  
• Diet. Deficiencies in folic acid and vitamin B-12 may cause symptoms of depression. Low levels of both nutrients are linked to a poorer response to antidepressant medications.

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Risk Factors

Depression affects all ages and all races. Typically, the first episode occurs between ages 25 and 44. It's not any more common in older adults, but it's more likely to go unrecognized in this age group.

Depression rates are lower among married people, especially married men, and those in long-term, intimate relationships. It's higher among divorced people and those who live alone.

Major depression, dysthymia and seasonal affective disorder are more common in women. Over the course of a lifetime, about one in five American women will experience major depression or dysthymia, compared with about 1 in 10 American men. Men and women have about the same risk of bipolar depression.

These gender differences may be in part due to biological causes, such as hormones and different levels of neurotransmitters.

When to Seek Medical Advice

If you feel sad, helpless, tired or worthless, if your eating and sleeping habits have changed greatly, and if you show little interest in once enjoyable activities, see your doctor to determine if depression is the cause. If you know someone who exhibits the characteristics of depression, encourage him or her to seek professional help.

Screening And Diagnosis

To diagnose depression, your doctor may perform a physical examination, including tests to rule out conditions that can cause symptoms that mimic depression.

If your doctor sees signs of severe depression or suspects the possibility of suicide, he or she may refer you to a medical doctor who specializes in mental illness (psychiatrist) or even recommend immediate hospitalization.

Your doctor or psychiatrist diagnoses depression based on the hallmark signs and symptoms of the disease, plus the presence of other signs and symptoms that typically accompany depression.

Complications

Depression is a serious illness that can take a terrible toll on individuals and families. Untreated, depression can lead to a downward spiral of disability, dependency and suicide. About 9 out of 10 people who commit suicide have one or more mental illnesses, most commonly depression.

As many as one in eight teens may have depression. The suicide rate for young adults ages 15 to 24 has risen in recent years. Among older adults, depression often is overlooked and therefore untreated. This may explain why the suicide rate for older adults is more than 50 percent higher than for the general population.

Certain warning signs may indicate serious depression and the possibility of suicide. Take any threat of suicide seriously, even if the person is already being treated for depression. If you see any of the following danger signs, call a doctor, mental health clinic or suicide hot line immediately:

• Pacing, agitated behavior, frequent mood changes and sleeplessness for several nights
  
  
• Actions or threats of assault, physical harm or violence
  
  
• Threats or talk of death or suicide, such as "I don't care anymore," or "You won't need to worry about me much longer"
  
  
• Withdrawal from activities and relationships
  
  
• Putting affairs in order, such as saying goodbye to friends, giving away prized possessions or writing a will
  
  
• A sudden brightening of mood after a period of being depressed
  
  
• Unusually risky behavior, such as buying or handling a gun or driving recklessly

Treatment

The development of newer antidepressant medications and mood-stabilizing drugs in the last 20 years has revolutionized the treatment of depression. Medication can relieve symptoms of depression, and it has become the first line of treatment for most types of the disorder.

Treatment may also include psychotherapy, which may help you cope with ongoing problems that may trigger or contribute to depression. A combination of medications and a brief course of psychotherapy usually is effective if you have mild to moderate depression. If you're severely depressed, initial treatment usually is with medications or electroconvulsive therapy. Once you improve, psychotherapy can be more effective.

Doctors usually treat depression in two stages. Acute treatment with medications helps relieve symptoms until you feel well. Once your symptoms ease, maintenance treatment typically continues for 6 to 12 months to prevent a relapse. It's important to keep taking your medication even though you feel fine and are back to your usual activities. Episodes of depression recur in the majority of people who have one episode, but continuing treatment for at least 6 months greatly reduces your risk of a rapid relapse. If you've had three or more previous episodes of depression, your doctor may suggest long-term treatment with antidepressants.

Medications

• Selective serotonin reuptake inhibitors (SSRIs). Doctors often consider selective serotonin reuptake inhibitors, such as fluoxetine (Prozac, Sarafem), paroxetine (Paxil), sertraline (Zoloft) and citalopram (Celexa), as the first-line treatment for depression because they have fewer serious side effects. They seem to work by increasing the availability of the neurotransmitter serotonin in your brain. Drugs similar to SSRIs include serotonin and norepinephrine reuptake inhibitors (SNRIs), such as nefazodone (Serzone), trazodone (Desyrel, Trialodine) and venlafaxine (Effexor), and dopamine reuptake inhibitors, such as bupropion (Wellbutrin, Zyban).
  
  
• Tricyclic and tetracyclic antidepressants. These medications also affect neurotransmitters but by a different mechanism than SSRIs. Doctors often prescribe them to treat moderate to severe depression. Among tricyclic antidepressants are amitriptyline (Elavil, Endep), desipramine (Norpramin, Pertofrane), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), trimipramine (Surmontil) and a combination of perphenazine and amitriptyline (Triavil, Etrafon). Tetracyclics include maprotiline (Ludiomil) and mirtazapine (Remeron).
  
  
• Monoamine oxidase inhibitors (MAOIs). These drugs, which include phenelzine (Nardil) and tranylcypromine (Parnate), prevent the breakdown of neurotransmitters. The drugs have potentially serious side effects if combined with certain other medications or food products. Doctors rarely use them unless other options have failed. Your doctor may prescribe them if you have chronic depression and eat or sleep excessively.
  
  
• Stimulants. If you're severely depressed, your doctor may initially prescribe a stimulant such as methylphenidate (Ritalin, Concerta), dextroamphetamine (Dexedrine, DextroStat) or modafinil (Provigil) in addition to an antidepressant because most antidepressants are slow to work. After 1 to 4 weeks, your doctor may then switch you to just an antidepressant.
  
  
• Lithium and mood-stabilizing medications. Doctors prescribe lithium (Eskalith, Lithobid), valproic acid (Depakene), divalproex (Depakote) and carbamazepine (Epitol, Tegretol, Carbatrol) to treat bipolar depression. These medications provide relief 50 percent to 80 percent of the time. Medications called atypical antipsychotics such as olanzapine (Zyprexa), risperidone (Risperdal) and quetiapine (Seroquel) were initially developed for treatment of psychotic disorders. Doctors sometimes also use them to treat bipolar disorder.

Most antidepressants have a similar level of effectiveness. However, a medication that works for someone else might not work for you. Doctors choose antidepressants based on your family history and the match between your symptoms and the medication's side effects. For example, if you have insomnia, a sedating antidepressant may help you. But if you're lethargic, then a more energizing antidepressant may be more helpful.

Most antidepressants are slow to work. You may see a response in 2 weeks, but many people don’t see a full benefit for 6 to 8 weeks. If your response to medication isn't resulting in satisfactory progress after 6 to 8 weeks, your doctor may suggest either adding another antidepressant or replacing the first medication with another drug from a different chemical family.

In addition to medications, depression treatment may include:

Psychotherapy

There are several types of psychotherapy. Each type involves a short-term, goal-oriented approach aimed at helping you deal with a specific issue. Prolonged psychotherapy is seldom necessary to treat depression. If an underlying factor contributing to your depression is an inability to get along with others or difficulty finding your place in life, then prolonged psychotherapy could help you.

The success of therapy depends on finding a doctor, psychiatrist or psychologist you're comfortable with. Both medications and psychotherapy can take 4 to 8 weeks to have an effect. Specialized and supervised group therapy, such as bereavement groups, stress management classes, marital counseling and family therapy, may also help.

Electroconvulsive therapy

Despite the images that many people conjure up, electroconvulsive therapy is generally safe and effective. In fact, it's the "gold standard" for treatment of severe depression.

In this therapy you receive a light general anesthesia and a muscle relaxant. An electrical current is passed through your brain for 1 to 3 seconds. The stimulus causes a controlled seizure, which typically lasts for 20 to 90 seconds. You wake up in 5 to 10 minutes and rest for about half an hour. Most people require 6 to 10 treatments.

Experts aren't sure how this therapy relieves symptoms of depression. The seizure may affect levels of neurotransmitters in your brain. The most common side effect is confusion that lasts a few minutes to several hours. A few people have some memory loss for several weeks. This therapy is usually used for people who don't respond to medications and for those at high risk of suicide. It may be the only treatment available for severely depressed older adults who can't take medications because of heart disease.

Light therapy

This therapy may help if you have seasonal affective disorder (SAD). This disorder involves periods of depression that recur at the same time each year, usually when days are shorter in the fall and winter. Scientists believe fewer hours of sunlight may increase levels of melatonin, a brain hormone thought to induce sleep and depress mood. Treatment with a specialized type of bright light, which suppresses production of melatonin, may help if you have this disorder.

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Self-Care

Once treatment for depression begins, you still have to manage on a day-to-day basis. Here are some guidelines:

• See your doctor regularly. Your doctor can monitor your progress, provide support and encouragement, and adjust your medication if necessary.
  
  
• Take your medications. Finding the best medication for you may take several tries. It may take several weeks for you to start seeing results. Once you feel better, continue to take your medication as prescribed.
  
  
• Don't become isolated. Try to participate in normal activities.
  
  
• Take care of yourself. Eat a healthy diet and get the right amount of sleep and exercise. Exercise can help treat some forms of depression, ease stress and help you relax.
  
  
• Avoid alcohol and recreational drugs. Abuse of alcohol and drugs will slow or prevent your recovery.

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Coping Skills

Self-help organizations have become potent allies for people who are coping with mental illness or who care about someone with such an illness. For depression or other mental illnesses, self-help groups include the National Mental Health Association (NMHA) and the National Alliance for the Mentally Ill (NAMI).

The NMHA is based in Washington, D.C., and has hundreds of affiliates in the United States. The group educates the public and the policy makers about mental health issues. The association's online resources include discussion groups and screening for depression.

The NAMI provides support and education to people with severe mental illness and their families. Founded in 1979, the group has more than 1,200 state and local chapters. The chapters rely on volunteers, most of whom have had mental illness in their families.

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Complementary and Alternative Medicine

Herbal and dietary supplements sold in stores have become increasingly popular. People take them to help prevent or treat a number of health conditions. Some of these alternative therapies are being studied to determine their effectiveness in helping depression. Within the next few years, researchers may know more about these products, how effective they are and if they can cause other health problems or interfere with medications.

In the meantime, talk with your doctor before taking any herbal or dietary supplement. The downfall of herbal and dietary products is that they aren't regulated. The Food and Drug Administration doesn't test them for safety, purity and effectiveness. You can't always be sure what you're getting and if it's safe.

Following are some of the more popular supplements marketed or taken for treatment of depression.

St. John's wort

St. John's wort is an herbal preparation from the Hypericum perforatum plant. It has long been used in folk medicine, and today it's widely prescribed in Europe to treat anxiety, depression and sleep disorders. In the United States it's sold in health food stores and pharmacies in the form of tablets or tea.

European studies suggest that St. John's wort may work as well as antidepressants and with fewer side effects. Adverse reactions include dry mouth, dizziness, digestive problems, fatigue, confusion and sensitivity to sunlight. In most cases, symptoms are mild. Of concern is that St. John's wort can interfere with the effectiveness of prescription medications, including antidepressants, drugs to treat human immunodeficiency virus (HIV) infections and AIDS, and drugs to prevent organ rejection in people who have had transplants. There's also a risk of serotonin syndrome if St. John's wort is used with an SSRI or another serotonin-active antidepressant.

The National Institute of Mental Health has begun a large-scale, controlled clinical trial of St. John's wort to help determine its effectiveness and safety.

SAM-e

Pronounced "Sammy," short for S-adenosyl-methionine, this chemical substance is available in Europe as a prescription drug to treat depression. In the United States it's sold as an over-the-counter dietary supplement.

SAM-e is a chemical substance found in all human cells and plays a role in many body functions. It's thought to increase levels of serotonin and dopamine, but this is unproven. Studies in Europe suggest it works as well as standard antidepressants but with milder side effects.

The pills are expensive, especially considering their effectiveness is unproven. Too much of the product could be harmful, boosting serotonin to dangerously high levels.

5-HTP

One of the raw materials that your body needs to make serotonin is a chemical called 5-HTP, which is short for 5-hydroxytryptophan. 5-HTP is prescribed in Europe to treat depression and other conditions, including obesity and insomnia. In the United States it's available as an over-the-counter supplement.

In theory, if you boost your body's level of 5-HTP, you should also elevate your levels of serotonin. One small study compared 5-HTP with the SSRI fluvoxamine. People taking three daily doses of 100 milligrams of 5-HTP reported slightly more relief and fewer side effects than did those taking fluvoxamine. But there's not enough evidence to determine if 5-HTP is effective and safe. Larger studies are needed.

In the 1980s a serious medical complication called erythromyalgia developed in some people who took 5-HTP from a bad batch. Many suffered permanent neurologic damage. This is an example of why you should be cautious when considering supplements.

Omega-3 fatty acids

Omega-3 fatty acids are found in fish oil and certain plants. They're being studied as a possible mood stabilizer for people with bipolar depression and other psychiatric disorders. Some studies suggest that people with depression have decreased amounts of an active ingredient found in omega-3 fatty acids. A recent small study also suggests that omega-3 fatty acids may prevent relapse among people with bipolar illness.

Fish oil capsules containing omega-3 fatty acids are sold in stores. The capsules are high in fat and calories and may produce gastrointestinal problems. Another way to get more omega-3 fatty acids is simply to eat more fish.

— April 3, 2002 —