What Is Major Depressive Disorder?

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What Is Major Depressive Disorder?

Major Depressive Disorder

Depression, also referred to as clinical depression or major depressive disorder, is a medical condition that is classified as a mood disorder. It can affect how you feel and your ability to function on a day-to-day basis.

While everyone tends to feel sad or low from time to time, feeling that way for weeks or months at a time could mean you have depression.

If you suspect you may have depression, you’re not alone. Over 8% of adults living in the United States have experienced at least one major depressive episode.

This article explores the symptoms, causes, and diagnosis of major depressive disorder, as well as some treatment options and coping strategies that may be helpful.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Symptoms of Major Depressive Disorder

These are some of the symptoms of major depressive disorder you may experience:

  • Feeling sad or low
  • Having an “empty” mood
  • Feeling anxious
  • Feeling guilty or helpless
  • Feeling worthless, hopeless, or pessimistic
  • Feeling restless, frustrated, or irritated
  • Losing interest in things you once enjoyed
  • Avoiding your usual activities
  • Having less energy and feeling fatigued
  • Moving or speaking slowly
  • Having difficulty paying attention, remembering, or making decisions 
  • Having difficulty sleeping, waking up too early, or oversleeping
  • Experiencing unplanned changes in eating habits and weight
  • Experiencing headaches, cramps, digestive issues, or other aches and pains that don’t have a clear cause and don’t get better with treatment
  • Talking about death, having thoughts of suicide, or attempting self-harm

Everyone experiences depression differently. While some people may have a few symptoms, others may have many. The frequency, severity, and duration of the symptoms can also vary from person to person.

Types of Depression

Depression may take different forms, or develop under certain circumstances. Accordingly, it may be classified into different types of depression, one of which is major depressive disorder.

The types of depression include:

  • Major depressive disorder: This is a form of depression where the person experiences symptoms for over two weeks. The symptoms affect their ability to eat, sleep, work, and function.
  • Persistent depressive disorder: Also known as dysthymia, this is a form of depression that lasts for over two years.
  • Perinatal depression: This is a form of depression people experience during pregnancy (known as antepartum depression) and after pregnancy (known as postpartum depression).
  • Premenstrual dysphoric disorder (PMDD): PMDD is a severe, disabling form of premenstrual syndrome (PMS) that can cause extreme mood swings.
  • Depression with psychotic features: A person may have psychotic depression if they have depression as well as psychosis, which is a condition that can make it hard to distinguish between what’s real and what isn’t.
  • Seasonal affective disorder (SAD): This is a form of depression that occurs in winter, when there is less natural sunlight.
  • Bipolar disorder: While bipolar disorder is not technically a type of depression, it can cause periods of low moods with similar symptoms to major depression.

Causes of Major Depressive Disorder

Depression is caused by an imbalance of chemicals, known as neurotransmitters, in the brain.

Certain genetic, biological, psychological, and environmental factors can increase the chances of someone developing depression; however, it’s important to remember that anyone can develop depression.

The potential causes and risk factors for depression include:

  • Biochemistry: Having differences in the levels of certain brain chemicals can make you more prone to developing depression.
  • Genetic factors: Genes can play a role in depression. Having a relative with depression can increase your chances of developing depression.
  • Personal medical history: You may be more likely to develop depression if you have had it before.
  • Gender: Women may be twice as likely to develop depression than men.
  • Life events: Trauma, the death of a loved one, major life changes, and other upsetting events can cause depression.
  • Stress: Stress can affect you physically and mentally, and increase your risk of developing depression.
  • Isolation: Lack of support and social isolation can increase the chances of developing depression.
  • Medical conditions: Depression may occur along with chronic or serious medical conditions like cancer, heart disease, diabetes, and Parkinson’s disease. Having depression can worsen these conditions.
  • Medication: Some medicines can cause depression as a side effect.
  • Substances: Substances such as alcohol or drugs can cause or exacerbate depression.
  • Personality: People who have difficulty coping with various life events may be more prone to developing depression.

Diagnosing Major Depressive Disorder

If you or a loved one have been feeling depressed and low, seek help as soon as possible. You can reach out to a mental healthcare provider or contact your primary care doctor for a diagnosis or referral.

Your healthcare provider will ask you a series of questions that will likely cover your symptoms, thoughts and feelings, and medical history. They may need to perform a physical or psychological exam, or conduct lab tests, in order to rule out other health conditions that can cause similar symptoms.

Your healthcare provider will determine whether or not your symptoms meet the diagnostic criteria for major depressive disorder, which include:

  • Having a persistently depressed mood and lack of interest in activities
  • Having five or more symptoms of depression
  • Having symptoms every day, almost all day
  • Having symptoms for over two weeks
  • Being unable to function like you did before, due to the symptoms

Treating Major Depressive Disorder

While depression is a serious condition, it can be treated. In fact, between 80% to 90% of people with depression respond well to treatment, and almost all patients get some relief from their symptoms.

It’s important to seek treatment for depression as soon as possible, because the earlier it is treated, the more effective the treatment can be. Ignoring the symptoms of depression and leaving it untreated can lead to self-harm or death.

Treatment for depression may involve medication, therapy, or brain stimulation. The treatment modalities chosen can depend on the severity of the depression and your individual needs.


Antidepressants are a type of medication that can help treat depression. They work by improving the balance of neurotransmitters in the brain. They are typically prescribed to treat moderate or severe cases of depression.

There are many different kinds of antidepressants, so you may need to try a few different types before you find the one that works best for you.

However, it’s important to note that antidepressants can take a few weeks or months to improve your mood, so you need to give the medication time to reach its full effect.


Psychotherapy, or talk therapy, can help treat depression. For mild cases of depression, your healthcare provider may recommend only psychotherapy, whereas for moderate to severe cases, a combination of medication and therapy may be recommended.

These are some of the types of therapy that can help treat depression:

  • Cognitive behavioral therapy (CBT): CBT can help you recognize unhelpful thought patterns contributing to depression. It can help you develop more positive thoughts and behaviors.
  • Psychodynamic therapy: Psychodynamic therapy can help you explore and understand how factors from your past, such as traumatic events, may have played a role in the development of depression.
  • Group therapy: This type of therapy is conducted in a group setting, rather than an individual setting. It can be helpful to interact with people who have similar experiences in a supportive environment.
  • Couples or family therapy: Family therapy can help address issues within the family, whereas couples therapy can help partners work through issues together.

You should expect to start feeling better after the first 10 to 15 sessions of therapy. The length of treatment can vary depending on how severe the depression is.

Brain Stimulation

Brain stimulation can help with severe cases of depression that aren’t responding to medication or therapy. The different types of brain stimulation include:

  • Electroconvulsive therapy (ECT): ECT involves electrical stimulation of the brain. The procedure is painless and you won't be able to feel the electrical impulses, but you will need to take a muscle relaxant and undergo brief anesthesia before each session.
  • Repetitive transcranial magnetic stimulation (rTMS): rTMS is a noninvasive procedure that involves placing an electromagnetic coil near your forehead. The coil delivers a magnetic pulse that stimulates nerve cells in the brain. rTMS is performed on an outpatient basis and doesn’t require anesthesia.
  • Vagus nerve stimulation (VNS): VNS involves implanting a device that sends pulses of electric energy to the brain, through the vagus nerve in the neck. You can think of it as a pacemaker for your brain. The device is inserted during a surgical procedure that may require an overnight stay in a hospital.

Coping With Major Depressive Disorder

These are some tips that can help you cope with depression:

  • Share your feelings with close friends and family members
  • Understand that recovery may be gradual, so set realistic goals for yourself
  • Postpone important decisions until you feel better
  • Stay active and exercise regularly
  • Maintain a consistent routine
  • Get enough sleep
  • Eat a balanced, nutritious diet
  • Avoid alcohol, nicotine, drugs, and medicines that have not been prescribed to you

A Word From Verywell

Major depressive order, a type of depression, is a serious medical condition that is caused by a chemical imbalance in the brain. It is neither a character flaw nor a weakness, and can happen to anyone.

If you or someone you know are experiencing depression, it’s important to seek treatment for it. Treatment can reduce the symptoms, help you cope, and enable you to function on a day-to-day basis.

12 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Sanjana Gupta
Sanjana is a health writer and editor. Her work spans various health-related topics, including mental health, fitness, nutrition, and wellness.