Depression is when feelings of loss, anger, sadness, or frustration make it hard for you to do the things you enjoy in everyday life. Although everyone feels sad sometimes, depression lasts longer and interferes with your daily life.

Depression is one of the most common illnesses, affecting about 18 million Americans each year. It can be mild, moderate, or severe. You can have a single episode of depression, or depression that comes back or lasts a long time (more than 2 years). Many experts think that depression is a chronic illness that needs long-term treatment.

The primary types of depression include:

• Major depression. A person must be depressed for at least 2 weeks, but often for as long as 20 weeks.
• Dysthymia. A long-lasting, less severe form of depression. Symptoms are like those of major depression but more mild. People with dysthymia have an greater risk of major depression.
• Atypical depression. Unlike those with major depression, people with atypical depression can feel better for a period of time when something good happens. In addition, people with atypical depression have different symptoms than those with major depression. Despite its name, atypical depression may be the most common type of depression.
• Adjustment disorder. Happens when someone's response to a major life event, such as the death of a loved one, causes symptoms of depression.

Other common forms of depression include:

• Postpartum depression. About 10% of mothers may have depression after giving birth
• Premenstrual dysphoric disorder (PDD). Women with PDD have symptoms 1 week before getting their period. Symptoms go away after their period.
• Seasonal affective disorder (SAD). A kind of depression that is seasonal and happens when there is less sunlight. It starts during fall-winter and disappears during spring-summer .
• Bipolar disorder. People with bipolar disorder have moods that swing from depression to mania. Also called manic-depressive disorder.

While it is normal to feel down sometimes, people with major depression feel significantly depressed for a long period of time. They have trouble enjoying things they used to love. Symptoms include:

• Sleep problems. At least 90% of people with depression have either insomnia or hypersomnia, meaning they sleep too much.
• Big change in appetite, often causing either weight loss or weight gain
• Fatigue and loss of energy
• Feelings of worthlessness, self-hate, and guilt
• Trouble concentrating
• Agitation, restlessness, irritability or inactivity, and withdrawal
• Recurring thoughts of death or suicide
• Feelings of hopelessness
• Not being interested in sex

No one knows exactly what causes depression, though scientists believe a combination of physical, genetic, and environmental factors are involved. People with depression may have abnormal levels of brain chemicals called neurotransmitters, including serotonin, dopamine, and norepinephrine. These things may contribute to having depression:

• Heredity. A gene called SERT that controls the brain chemical serotonin has been linked to depression. In addition, some studies show that people with depressed family members are more likely to be depressed.
• Changes in the brain. Imaging studies suggest that people with depression have structural changes in their brains.
• Long-term stress, such as from loss, abuse, or being neglected as a child
• Being exposed to low levels of light, in SAD
• Sleep problems
• Social isolation
• Vitamin and mineral deficiencies
• Serious medical conditions, such as heart attack, cancer, Parkinson disease, and arthritis
• Certain medicines, including those for high blood pressure, high cholesterol, or irregular heartbeat

Although depression can happen to anyone, no matter what age, race, or gender, the following factors may increase your risk for depression:

• Previous episodes of depression
• Family history of depression
• Suicide attempt. Having made a suicide attempt while depressed raises the risk of another episode of depression
• Being a woman. More women than men seem to have depression. This may be because women tell their doctors about their symptoms more often than men. Or hormone changes may make women more likely to have depression.
• Stressful life events, such as the death of a loved one
• Recently giving birth to a baby (postpartum)
• Having a long-lasting illness, including autoimmune diseases (such as lupus), cancer, heart disease, chronic headaches, chronic pain, arthritis, anxiety, obsessive-compulsive disorder, and borderline personality disorder. Medical conditions that cause hormonal shifts, such as thyroid disorders or menopause, may also contribute to depression.
• History of abuse, such as mental, physical, or sexual
• Lack of support, such as a network of close friends or family
• Alcohol or drug abuse. 25% of people with addictions have depression.

If you feel depressed, or have symptoms of depression, it is important to tell your doctor. Depression does not usually go away on its own. Telling your doctor is the first step toward treatment. Talk to your primary care doctor or a mental health provider.

If you have thoughts of suicide, call 911 or a local emergency hotline. It is important to talk to someone immediately. You can also call a family member or friend, your minister, or someone in your faith community.

Your doctor may run tests to rule out other conditions. Your doctor will take a medical history and ask about your symptoms. Your doctor may also order blood tests to check your thyroid function and other conditions and may refer you to a psychiatrist.

Although most people with depression are treated as outpatients, people with suicidal thoughts may need to be hospitalized.

Although there is no guarantee you can prevent depression, the following steps may help:

• Getting enough sleep and regular exercise and eating a balanced, healthy diet may help prevent depression and reduce symptoms.
• Mind-body techniques, such as biofeedback, meditation, and tai chi, may help prevent or reduce symptoms of depression.
• Psychotherapy that helps you learn coping skills may help prevent relapse.
• Family therapy may prevent children or teens of depressed parents from becoming depressed later in life.
• Taking medicine as prescribed lowers the chance of relapse.

People with depression have several options for treatment. Most experts think a combination of psychotherapy and antidepressants is best, especially for people with major depression. Cognitive-behavioral therapy may be the type of psychotherapy that works best, particularly for teens and people with atypical or postpartum depression.

Most people with depression get better with this combination treatment. Complementary and alternative therapies (CAM) may help either reduce the side effects from antidepressants, or reduce the symptoms of mild-to-moderate depression.

Many herbs and supplements can interact with medications taken for depression and cause unwanted side effects. Be sure to talk to your doctor before trying any herb or supplement.

Lifestyle

Exercise

Studies show that regular exercise, either aerobic or strength and flexibility training, can reduce depression in people with mild-to-moderate depression. For people with major depression, exercise also improves their mood. Some studies even suggest that exercise may work as well as psychotherapy for people with mild-to-moderate depression, although more research is needed. In the meantime, it makes sense to exercise, whether or not you are taking medications or receiving therapy for depression.

Light Therapy

Light therapy, being exposed to a bright light as soon as you wake up in the morning, may help people with SAD.

Medications

Antidepressant medications can work well in treating depression, although you may have to try a few different medications to find the one that works best for you. In general, antidepressants are taken for at least 4 to 6 months. Most medications take 2 to 4 weeks to start working, and may take up to 12 weeks for their full effects to kick in.

Antidepressants can have unwanted side effects, making it hard for some people to keep taking their medications. Often you can work with your doctor to find a medication that has fewer side effects. DO NOT stop your medication without talking to your doctor. Most antidepressants cause withdrawal symptoms if they are not stopped slowly over time or tapered down.

Note: The Food and Drug Administration (FDA) requires all antidepressants to carry a "black-box warning" saying that people under age 25 may have an increase in suicidal thoughts or behavior in the first weeks after taking an antidepressant or when the dose is changed. People under 25 should be watched closely when taking antidepressants.

There are several types of antidepressant medications, including:

Selective Serotonin Reuptake Inhibitors (SSRIs)

SSRIs: increase the activity of a chemical in the brain called serotonin. Most doctors prescribe SSRIs first for depression, in part because their side effects are generally fewer than other antidepressants. Typical side effects caused by SSRIs include stomach upset, weight gain or loss, drowsiness, sexual dysfunction (such as impotence, loss of sex drive, and diminished orgasm), headache, jaw grinding, and apathy. Very unusual side effects from this class of prescription drugs include extreme agitation, impulsivity, tremors, and insomnia.

Drugs that are SSRIs include:

• Fluoxetine (Prozac)
• Sertraline (Zoloft)
• Paroxetine (Paxil), most likely in this class to cause sexual dysfunction
• Fluvoxamine (Luvox)
• Escitalopram (Lexapro)
• Citalopram (Celexa), least likely in this class to cause sexual dysfunction

Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs)

SNRIs: are often the second kind of antidepressants prescribed. They increase the amount of the chemicals serotonin and norepinephrine available in the brain, and have fewer side effects than other antidepressants. Side effects can include nausea, insomnia, nervousness, rash, or sexual dysfunction.

Drugs that are SNRIs include:

• Duloxetine (Cymbalta)
• Venlafaxine (Effexor)

Norepinephrine-Dopamine Reuptake Inhibitor (NDRI)

This kind of drug increases the amount of the chemicals norepinephrine and dopamine available in the brain. Bupropion (Wellbutrin) is the only approved drug in this class. It does not seem to cause sexual dysfunction or weight gain, but people with a risk or history of seizure should not take it.

Tricyclic Antidepressants

Tricyclics: increase the activity of the brain chemicals serotonin and norepinephrine. They work as well as SSRIs, but they are an older kind of antidepressant with more side effects. They are usually prescribed only when other antidepressants have not worked. Tricyclic antidepressants include:

• Amitriptyline (Elavil)
• Amoxapine
• Clomipramine (Anafranil)
• Desipramine (Norpramin)
• Doxepin (Sinequan), may help with insomnia
• Imipramine (Tofranil)
• Nortriptyline (Pamelor)
• Protriptyline (Vivactil)
• Trimipramine (Surmontil, Rhotrimine)

Side effects of tricyclics may include:

• Dry mouth
• Blurred vision
• Constipation
• Sexual dysfunction
• Weight gain
• Dizziness
• Drowsiness
• Urinary urgency, a feeling that you have to urinate even when your bladder is empty
• Drop in blood pressure when going from lying or sitting to standing, which causes dizziness and lightheadedness
• Irregular heart rhythm

Monoamine Oxidase Inhibitors (MAOIs)

MAOIs: boost levels of norepinephrine, dopamine, and serotonin in the brain. They are an older class of antidepressants and are rarely prescribed because they can have serious side effects. People who take MAOIs have to avoid certain chemicals, called tyramines, in their diet. Tyramines are found in fish, alcohol, cheeses, processed meats, and other food. MAOIs also interact with other medications, including Ritalin and pseudoephedrine, a decongestant in many over-the-counter and prescription medications. You should not take MAOIs with other kinds of antidepressants.

Surgery and Other Procedures

Doctors may recommend:

Electroconvulsive Therapy (ECT) for depression when all other therapies have not worked. In ECT, a small electrical current is passed through the brain to cause a seizure. Scientists are not sure how ECT works, but it may boost levels of neurotransmitters in the brain. It may cause temporary confusion and memory loss, headache, muscle aches, irregular heart rhythm, or nausea. For some people, it relieves severe depression and works quickly.

Magnetic Resonance Imaging (MRI)-Guided Cingulotomy involves stimulating the brain with electrodes that are surgically implanted. It is an experimental treatment for people who have treatment-resistant depression.

Vagus Nerve Stimulation (VNS) involves surgically implanting a device that stimulates the vagus nerve. It was first developed for epilepsy, but seems to work for some people with treatment-resistant depression. The device is placed under the skin in the chest.

Nutrition and Dietary Supplements

A treatment plan for depression may include complementary and alternative therapies. Preliminary studies suggest some nutritional supplements may reduce the symptoms of depression for some people. It is important to talk to your team of health care providers about the best ways to use these therapies in your overall treatment plan.

DO NOT try to treat moderate or severe depression on your own. Always tell your provider about the herbs and supplements you are using or considering using.

The following supplements may help reduce symptoms:

• SAMe (s-adenosyl-L-methionine) is a substance your body makes that may raise levels of the brain chemical dopamine. It has been studied for depression, but results are mixed and not all of the studies have been of good quality. Some of the studies suggest SAMe can help relieve mild-to-moderate depression and may work faster than prescription antidepressants. If you are taking other medications for depression, talk to your doctor before taking SAMe because it may interact with them.
• 5-HTP (5-hydroxytryptophan) may help raise serotonin levels in the brain. 5-HTP is a precursor to serotonin, meaning your body changes it to serotonin. Early studies suggest it may work like antidepressant drugs. In rare cases, contaminated 5-HTP was linked to a potentially fatal condition called eosinophilia-myalgia syndrome. Taking 5-HTP with other antidepressants can cause serotonin levels in the brain to rise to dangerous levels, a condition called serotonin syndrome. You should not take 5-HTP without your doctor's supervision.
• Omega-3 fatty acids, such as those found in fish oil, may help relieve symptoms of depression, but evidence is mixed. Some studies suggest that fish oil, when taken with prescription antidepressants, works better than antidepressants alone. However, a review of several studies did not find any benefit. Preliminary studies suggest that one of the omega-3 fatty acids in fish oil called EPA helps relieve depression when taken with an antidepressant. Fish oil taken in high doses may increase the risk of bleeding. DO NOT take it if you also take blood thinners, such as warfarin (Coumadin), clopidogrel (Plavix), or daily aspirin.
• Vitamin B6, for women with premenstrual dysphoric disorder. A few studies suggest that vitamin B6 may help relieve depression that occurs with premenstrual syndrome, although the evidence is mixed. The studies used high doses, which require a doctor's supervision. Other studies suggest that B6 may also help with other types of depression. More research is needed.
• Studies have found that some people with depression may have low levels of folic acid, vitamin B12, or vitamin D. If you have depression, you may want to ask your doctor to check your levels. So far there is no proof that taking any of these vitamins helps relieve depression. But one study suggested that women who took folic acid supplements along with Prozac did better than those who took only Prozac.

Herbs

Herbs may strengthen and tone the body's systems. As with any therapy, you should work with your health care provider before starting treatment.

• St. John's wort (Hypericum perforatum) standardized extract, for mild-to-moderate depression. St. John's wort has been studied extensively for depression. Most studies show it works as well as antidepressants for mild-to-moderate depression. It has fewer side effects than most antidepressants. It may take 4 to 6 weeks before you see any improvement. St. John's wort interacts with a large number of medications, including birth control pills, so check with your doctor if you are taking prescription medications. DO NOT use St. John's wort to treat severe depression.
• Saffron (Crocus satvius) standardized extract, may help relieve depression although it is too soon to say for sure. One preliminary study found that it worked as well as Prozac, while another found that it worked as well as a low dose of Tofranil. Saffron can be dangerous or even life-threatening at high doses or when taken for a long time, so DO NOT take it without your doctor's supervision. Pregnant women and people with bipolar disorder should not take saffron supplements.
• Ginkgo (Ginkgo biloba) standardized extract, 40 to 80 mg, 3 times daily, for depression. A few studies looking at gingko for treating memory problems in older adults seemed to show that it also improved symptoms of depression. One laboratory study found that gingko, when given to older rats, increased the number of serotonin-binding sites in their brains. It did not affect younger rats, so researchers thought that it might relieve depression in older adults by helping their brains respond better to serotonin. More research is needed. Gingko may increase the risk of bleeding, especially if you also take blood thinners such as warfarin (Coumadin), clopidogrel (Plavix), or aspirin. Ask your doctor before taking gingko.

Acupuncture

Preliminary studies suggest that electroacupuncture may reduce symptoms of depression as well as Elavil, a tricyclic antidepressant. In electroacupuncture, a small current runs through acupuncture needles. Other studies suggest that acupuncture may help people with mild depression, and those with depression related to a chronic medical illness. More research is needed.

Homeopathy

Although few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider the following remedies for depression based on their knowledge and experience.

Before prescribing a remedy, homeopaths take into account a person's constitutional type, includes your physical, emotional, and intellectual makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each person. A few homeopathic remedies that may work for depression include:

• Ignatia, for a sudden sense of grief or disappointment following the death of a loved one, the end of a romantic relationship, or an unexpected loss of one's job
• Natrum muriaticum, for grief following the death of a loved one or sadness from the end of a romantic relationship

Massage and Physical Therapy

Studies of formerly depressed teen mothers, children hospitalized for depression, and women with eating disorders suggest that massage can help reduce stress, anxiety, and symptoms of depression. Giving massage may also help people who are depressed. Elderly volunteers with depression had fewer symptoms when they massaged infants.

Aromatherapy, or using essential oils in massage therapy, may also help treat depression. Aromatherapy seems to work because it helps people relax. The person's belief that it will help also has an effect. Essential oils used during massage for depression include:

• Lavender (Lavandula officinalis)
• Basil (Ocimum basilicum)
• Orange (Citrus aurantium)
• Sandalwood (Santalum album)
• Lemon (Citrus limonis)
• Jasmine (Jasminum spp.)
• Sage (Salvia officinalis)
• Chamomile (Chamaemelum nobile)
• Peppermint (Mentha piperita)
• Rosemary (Rosmarinus officinalis)

Mind-Body Medicine

Mind-body therapies and techniques that may be useful as a part of an overall treatment regimen for depression include:

Psychotherapy

Cognitive-behavioral therapy (CBT) is a kind of therapy where people learn to identify and change negative thoughts and feelings so they can better cope with the world around them. This therapy works well for people with mild-to-moderate depression, but your doctor may not recommend it if you have severe depression.

People treated with CBT had just as good, or better, results as those treated with tricyclic antidepressants. They also had lower relapse rates than those taking antidepressants.

Other types of therapy that a psychiatrist, psychologist, or social worker may offer include:

• Psychodynamic psychotherapy. Looks at unresolved conflicts in childhood and depression as a grief process
• Interpersonal therapy. Focuses on current problems and relationships. It works well for depression
• Supportive psychotherapy. Nonjudgmental advice, attention, and sympathy. This approach may help people to continue taking their medication

Tai Chi and Yoga

Several studies suggest that mind-body techniques, such as yoga, qi gong, and tai chi, may improve symptoms of mild depression.

Meditation

Some researchers believe that mindfulness meditation may prevent depression from coming back.

Pregnancy

• About 10 to 20% of women have postpartum depression after giving birth.
• Researchers are not completely sure about the safety of SSRIs and tricyclic antidepressant medications during pregnancy. It is best to talk with your doctor about the risks and benefits of your medication before you try to get pregnant. Avoid MAOIs during pregnancy.
• Many of the dietary supplements and herbs mentioned here have not been tested for safety during pregnancy. Talk with your doctor or pharmacist.

Warnings and Precautions

• People with Parkinson disease should not take SSRIs.
• People with coronary artery disease should not take tricyclic antidepressants.
• Some herbal remedies and supplements should not be combined with antidepressants. Be sure to tell your health care provider about all herbs and supplements you take.

Prognosis and Complications

Depression is a serious condition that can have a devastating effect on people's lives. It can contribute to long-lasting medical conditions, such as heart disease and stroke. Depressed people with these conditions are less likely to do healthy activities, such as exercise, and more likely to do unhealthy activities, such as smoking.

Suicide is a significant risk for people with depression. About 15% of people with a major depressive disorder commit suicide. Depression also shortens the lifespan of the elderly and is linked to memory problems and dementia.

Left untreated, depression can last up to 2 years or longer. Depression is likely to come back: 50% of people who have had one depressive episode will have a second one, 70% of those who have two episodes will have a third, and 90% of those who have three episodes will have a fourth. For women with premenstrual dysphoric disorder or SAD, symptoms usually go away after menopause.

Fortunately, there are many treatments available for depression. The prognosis is much better for people who get treatment and follow their doctor's recommendations.

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