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Depression (major depressive disorder or clinical depression) is a common but serious mood disorder. It causes severe symptoms that affect how you feel, think, and handle daily activities, such as sleeping, eating, or working. To be diagnosed with depression, the symptoms must be present for at least two weeks.

Some forms of depression are slightly different, or they may develop under unique circumstances, such as:

  • Persistent depressive disorder (also called dysthymia) is a depressed mood that lasts for at least two years. A person diagnosed with persistent depressive disorder may have episodes of major depression along with periods of less severe symptoms, but symptoms must last for two years to be considered persistent depressive disorder.
  • Perinatal depression is much more serious than the “baby blues” (relatively mild depressive and anxiety symptoms that typically clear within two weeks after delivery) that many women experience after giving birth. Women with perinatal depression experience full-blown major depression during pregnancy or after delivery (postpartum depression). The feelings of extreme sadness, anxiety, and exhaustion that accompany perinatal depression may make it difficult for these new mothers to complete daily care activities for themselves and/or for their babies.
  • Psychotic depression occurs when a person has severe depression plus some form of psychosis, such as having disturbing false fixed beliefs (delusions) or hearing or seeing upsetting things that others cannot hear or see (hallucinations). The psychotic symptoms typically have a depressive “theme,” such as delusions of guilt, poverty, or illness.
  • Seasonal affective disorder is characterized by the onset of depression during the winter months, when there is less natural sunlight. This depression generally lifts during spring and summer. Winter depression, typically accompanied by social withdrawal, increased sleep, and weight gain, predictably returns every year in seasonal affective disorder.
  • Bipolar disorder is different from depression, but it is included in this list is because someone with bipolar disorder experiences episodes of extremely low moods that meet the criteria for major depression (called “bipolar depression”). But a person with bipolar disorder also experiences extreme high – euphoric or irritable – moods called “mania” or a less severe form called “hypomania.”

Examples of other types of depressive disorders newly added to the diagnostic classification of DSM-5  include disruptive mood dysregulation disorder (diagnosed in children and adolescents) and premenstrual dysphoric disorder (PMDD).

Signs and Symptoms

If you have been experiencing some of the following signs and symptoms most of the day, nearly every day, for at least two weeks, you may be suffering from depression:

  • Persistent sad, anxious, or “empty” mood
  • Feelings of hopelessness, or pessimism
  • Irritability
  • Feelings of guilt, worthlessness, or helplessness
  • Loss of interest or pleasure in hobbies and activities
  • Decreased energy or fatigue
  • Moving or talking more slowly
  • Feeling restless or having trouble sitting still
  • Difficulty concentrating, remembering, or making decisions
  • Difficulty sleeping, early-morning awakening, or oversleeping
  • Appetite and/or weight changes
  • Thoughts of death or suicide, or suicide attempts
  • Aches or pains, headaches, cramps, or digestive problems without a clear physical cause and/or that do not ease even with treatment

Not everyone who is depressed experiences every symptom. Some people experience only a few symptoms while others may experience many. Several persistent symptoms in addition to low mood are required for a diagnosis of major depression, but people with only a few – but distressing – symptoms may benefit from treatment of their “subsyndromal” depression. The severity and frequency of symptoms and how long they last will vary depending on the individual and his or her particular illness. Symptoms may also vary depending on the stage of the illness.

Risk Factors

Depression is one of the most common mental disorders in the U.S. Current research suggests that depression is caused by a combination of genetic, biological, environmental, and psychological factors.

Depression can happen at any age, but often begins in adulthood. Depression is now recognized as occurring in children and adolescents, although it sometimes presents with more prominent irritability than low mood. Many chronic mood and anxiety disorders in adults begin as high levels of anxiety in children.

Depression, especially in midlife or older adults, can co-occur with other serious medical illnesses, such as diabetes, cancer, heart disease, and Parkinson’s disease. These conditions are often worse when depression is present. Sometimes medications taken for these physical illnesses may cause side effects that contribute to depression. A doctor experienced in treating these complicated illnesses can help work out the best treatment strategy.

Risk factors include:

  • Personal or family history of depression
  • Major life changes, trauma, or stress
  • Certain physical illnesses and medications

Treatment and Therapies

Depression, even the most severe cases, can be treated. The earlier that treatment can begin, the more effective it is. Depression is usually treated with medications, psychotherapy, or a combination of the two. If these treatments do not reduce symptoms, electroconvulsive therapy (ECT) and other brain stimulation therapies may be options to explore.

Quick Tip: No two people are affected the same way by depression and there is no "one-size-fits-all" for treatment. It may take some trial and error to find the treatment that works best for you.


Antidepressants are medicines that treat depression. They may help improve the way your brain uses certain chemicals that control mood or stress. You may need to try several different antidepressant medicines before finding the one that improves your symptoms and has manageable side effects. A medication that has helped you or a close family member in the past will often be considered.

Antidepressants take time – usually 2 to 4 weeks – to work, and often, symptoms such as sleep, appetite, and concentration problems improve before mood lifts, so it is important to give medication a chance before reaching a conclusion about its effectiveness. If you begin taking antidepressants, do not stop taking them without the help of a doctor. Sometimes people taking antidepressants feel better and then stop taking the medication on their own, and the depression returns. When you and your doctor have decided it is time to stop the medication, usually after a course of 6 to 12 months, the doctor will help you slowly and safely decrease your dose. Stopping them abruptly can cause withdrawal symptoms.

Please Note: In some cases, children, teenagers, and young adults under 25 may experience an increase in suicidal thoughts or behavior when taking antidepressants, especially in the first few weeks after starting or when the dose is changed. This warning from the U.S. Food and Drug Administration (FDA) also says that patients of all ages taking antidepressants should be watched closely, especially during the first few weeks of treatment.

If you are considering taking an antidepressant and you are pregnant, planning to become pregnant, or breastfeeding, talk to your doctor about any increased health risks to you or your unborn or nursing child.

To find the latest information about antidepressants, talk to your doctor and visit .

You may have heard about an herbal medicine called St. John's wort. Although it is a top-selling botanical product, the FDA has not approved its use as an over-the-counter or prescription medicine for depression, and there are serious concerns about its safety (it should never be combined with a prescription antidepressant) and effectiveness. Do not use St. John’s wort before talking to your health care provider. Other natural products sold as dietary supplements, including omega-3 fatty acids and S-adenosylmethionine (SAMe), remain under study but have not yet been proven safe and effective for routine use. For more information on herbal and other complementary approaches and current research, please visit the National Center for Complementary and Integrative Health  website.


Several types of psychotherapy (also called “talk therapy” or, in a less specific form, counseling) can help people with depression. Examples of evidence-based approaches specific to the treatment of depression include cognitive-behavioral therapy (CBT), interpersonal therapy (IPT), and problem-solving therapy. More information on psychotherapy is available on the NIMH website and in the NIMH publication Depression: What You Need to Know.

Brain Stimulation Therapies

If medications do not reduce the symptoms of depression, electroconvulsive therapy (ECT) may be an option to explore. Based on the latest research:

  • ECT can provide relief for people with severe depression who have not been able to feel better with other treatments.
  • Electroconvulsive therapy can be an effective treatment for depression. In some severe cases where a rapid response is necessary or medications cannot be used safely, ECT can even be a first-line intervention.
  • Once strictly an inpatient procedure, today ECT is often performed on an outpatient basis. The treatment consists of a series of sessions, typically three times a week, for two to four weeks.
  • ECT may cause some side effects, including confusion, disorientation, and memory loss. Usually these side effects are short-term, but sometimes memory problems can linger, especially for the months around the time of the treatment course. Advances in ECT devices and methods have made modern ECT safe and effective for the vast majority of patients. Talk to your doctor and make sure you understand the potential benefits and risks of the treatment before giving your informed consent to undergoing ECT.
  • ECT is not painful, and you cannot feel the electrical impulses. Before ECT begins, a patient is put under brief anesthesia and given a muscle relaxant. Within one hour after the treatment session, which takes only a few minutes, the patient is awake and alert.

Other more recently introduced types of brain stimulation therapies used to treat medicine-resistant depression include repetitive transcranial magnetic stimulation (rTMS) and vagus nerve stimulation (VNS). Other types of brain stimulation treatments are under study. You can learn more about these therapies on the NIMH Brain Stimulation Therapies webpage.

If you think you may have depression, start by making an appointment to see your doctor or health care provider. This could be your primary care practitioner or a health provider who specializes in diagnosing and treating mental health conditions. Visit the NIMH Find Help for Mental Illnesses if you are unsure of where to start.

Beyond Treatment: Things You Can Do

Here are other tips that may help you or a loved one during treatment for depression:

  • Try to be active and exercise.
  • Set realistic goals for yourself.
  • Try to spend time with other people and confide in a trusted friend or relative.
  • Try not to isolate yourself, and let others help you.
  • Expect your mood to improve gradually, not immediately.
  • Postpone important decisions, such as getting married or divorced, or changing jobs until you feel better. Discuss decisions with others who know you well and have a more objective view of your situation.
  • Continue to educate yourself about depression.

Join a Study

What are Clinical Trials?

Clinical trials are research studies that look at new ways to prevent, detect, or treat diseases and conditions, including depression. During clinical trials, some participants receive treatments under study that might be new drugs or new combinations of drugs, new surgical procedures or devices, or new ways to use existing treatments. Other participants (in the “control group”) receive a standard treatment, such as a medication already on the market, an inactive placebo medication,  or no treatment. The goal of clinical trials is to determine if a new test or treatment works and is safe. Although individual participants may benefit from being part of a clinical trial, participants should be aware that the primary purpose of a clinical trial is to gain new scientific knowledge so that others may be better helped in the future.

Please Note: Decisions about whether to participate in a clinical trial, and which ones are best suited for a given individual, are best made in collaboration with your licensed health professional.

How do I find a Clinical Trials at NIMH on Depression?

Doctors at NIMH are dedicated to mental health research, including clinical trials of possible new treatments as well as studies to understand the causes and effects of depression. The studies take place at the NIH Clinical Center in Bethesda, Maryland and require regular visits. After the initial phone interview, you will come to an appointment at the clinic and meet with one of our clinicians. Find NIMH studies currently recruiting participants with depression by visiting Join a Research Study: Depression.

How Do I Find a Clinical Trial Near Me?

To search for a clinical trial near you, you can visit . This is a searchable registry and results database of federally and privately supported clinical trials conducted in the United States and around the world (search: depression). gives you information about a trial's purpose, who may participate, locations, and contact information for more details. This information should be used in conjunction with advice from health professionals.

Learn More

Free Booklets and Brochures

  • Chronic Illness & Mental Health: This brochure discusses chronic illnesses and depression, including symptoms, health effects, treatment, and recovery.
  • Depression and College Students: This brochure describes depression, treatment options, and how it affects college students.
  • Depression and Older Adults: Depression is not a normal part of aging. This brochure describes the signs, symptoms, and treatment options for depression in older adults.
  • Depression: What You Need to Know: This booklet contains information on depression including signs and symptoms, treatment and support options, and a listing of additional resources.
  • Postpartum Depression Facts: A brochure on postpartum depression that explains its causes, symptoms, treatments, and how to get help.
  • Teen Depression: This flier for teens describes depression and how it differs from regular sadness. It also describes symptoms, causes, and treatments, with information on getting help and coping.

Clinical Trials

Federal Resources

Research and Statistics


Last Revised: October 2016

Unless otherwise specified, NIMH information and publications are in the public domain and available for use free of charge. Citation of the NIMH is appreciated. Please see our Citing NIMH Information and Publications page for more information.