What is major depressive disorder? Plus symptoms & treatment


Editorial Team


April 27, 2021

young asian woman with major depressive disorder watching sunrise
Though major depressive disorder can have a significant impact on your life, it usually responds well to treatment.

Most people feel occasional sadness, grief, or low self-esteem. But when your feelings of depression interfere with your ability to function, it may be a sign of a clinical disorder. One of the most common types of clinical depression is called major depressive disorder.

For people with anxiety and depression, purposefully engaging in pleasurable activities can improve mental health.
Though major depressive disorder can have a significant impact on your life, it usually responds well to treatment.

Most people feel occasional sadness, grief, or low self-esteem. But when your feelings of depression interfere with your ability to function, it may be a sign of a clinical disorder. One of the most common types of clinical depression is called major depressive disorder.

What is major depressive disorder (MDD)?

Major depressive disorder, or MDD—its medical abbreviation—is a mood disorder that causes mood and can interfere with your daily life.

You may have heard this disorder referred to as major depression, clinical depression, or unipolar depression. In clinical shorthand, MDD is also commonly referred to simply as depression. Major depressive episodes affect an estimated 17.3 million people in the United States each year.

People with MDD often experience feelings of intense sadness, despair, and hopelessness. In addition to impacting your mood, this condition can also cause physical symptoms like pain, sleep disturbances, and changes in your appetite. The depressive episodes might be recurrent, or the experience of depression may be continuous.

Although depressive episodes may interrupt your life, there is help and hope available. You’re not in this alone, and there are multiple ways you can successfully treat this condition.

Many people discover they’re able to overcome their symptoms of depression with medication, therapy, behavioral and lifestyle changes, or a combination of treatments. If you’re dealing with major depression, we want you to know that help is available.

In a psychiatric emergency, call 911 or visit your nearest emergency room. Anyone with suicidal thoughts can also call the National Suicide Prevention Hotline 1-800-273-8255 or text “home” to 741-741.


The cause of major depressive disorder remains the subject of research. That being said, scientists and researchers can point to several contributing factors, including a chemical imbalance in the brain, hormonal changes, genetic predisposition, stressful life events, or some combination of these factors.

Studies have shown that specific genes may make you more vulnerable to mood swings or hormonal changes. We also know that there’s a link between certain brain regions and depression. For example, people with depression sometimes have a smaller hippocampus, part of the brain responsible for learning and memory.

The nerve cells in your brain may also contribute to feelings of depression. Neurotransmitters that experience breakdowns in communication may lead to depression, especially when your neurobiology is overly sensitive or insensitive to a particular chemical messenger.

No single gene or neurotransmitter has been identified as the overarching cause of all major depressive disorders. Researchers are still studying the many unknowns of how and why these elements lead to depression. For instance, scientists continue to research the precise genetic and environmental factors that contribute to depression that runs in families.

Risk factors

The following factors may increase your risk of developing clinical depression:

Age and biological sex

Women are more likely to be diagnosed with major depressive disorder than men. Most people experience the onset of symptoms in their teens or during early adulthood.

Stressful life events

Environmental factors, such as trauma, sexual abuse, the loss of a loved one, or relationship issues, can contribute to a depressive episode.

Other mental health disorders

Of the people who seek treatment for a depressive or anxiety disorder, more than 50% also have another mental health condition. The co-occurrence of more than one disorder in the same person is known as comorbidity.


Your mental habits have an impact on your emotional resilience. Scientists believe that personality traits, such as excitability and frequent self-criticism, may make you more vulnerable to depressive episodes.

Sexual orientation and gender identity

Lesbian, gay, bisexual, transgender, and intersex people are more likely to experience clinical depression, especially if they live in an unsupportive or openly hostile environment.

Substance abuse

Alcohol and recreational drugs can worsen depressive symptoms. Depression often co-occurs with substance use disorders.

Chronic illness

Serious illnesses, such as cancer, stroke, chronic pain, or heart disease, can lead to depression.

Medication side effects

Sleeping pills or certain blood pressure medications can cause side effects, including depressive symptoms.


Without treatment, depression can worsen and become more challenging to treat— including the development of complications that can be serious.

Complications of major depressive disorder include:

Pain and physical illness

Not only can depressive disorders include physical symptoms, like back pain and headaches, but they are also associated with physical illnesses. These include fibromyalgia, chronic fatigue, heart attack, and irritable bowel syndrome.

Substance abuse

Many people experiencing depression also experience addiction or substance abuse issues. People with mood disorders are more than twice as likely to become addicted to drugs.

Other mental health disorders

It’s common for major depression to present alongside another mental health condition, like anxiety. Research suggests that your symptoms may be more severe if you have more than one mental health disorder. One study found that people with both MDD and panic disorder experienced more severe panic attack symptoms.

Relationship conflicts

Depression often disrupts intimate relationships. It can also cause issues in relationships with colleagues, family, friends, classmates, and teachers.

Loneliness and isolation

Social isolation that results from depression may cause cognitive decline, poor cardiovascular health, poor sleep, and decreased immune responsiveness.

Weight changes

Depression can increase your risk of obesity, heart disease, and diabetes. For people experiencing body dysmorphia or eating disorders, depression can make these mental health issues even worse.


Although most people with depression are not suicidal, the condition is associated with an elevated risk of self-harm, including suicidal thoughts and actions.


If you have 5 or more of the following MDD symptoms for more than two weeks, you may be experiencing a major depressive episode.

  • Depressed mood, or an irritable mood if you’re a child or adolescent
  • Loss of interest in almost all activities
  • Significant change in weight, more than 5 percent a month, or appetite
  • Sleep disruptions— either sleeping too much or too little
  • Moving faster or slower than usual in a way that’s noticeable to others
  • Tiredness, fatigue, low energy, or a decrease in productivity
  • Sense of worthlessness or a level of guilt that’s out of proportion to the situation
  • Inability to think clearly, concentrate, or make decisions
  • Recurrent thoughts of death and suicide, or attempting suicide

People with the above major depressive disorder symptoms may also experience distress or impairment due to these symptoms. These disruptions can impact relationships, work, school, and other essential responsibilities.

Testing & diagnosis

To be diagnosed with clinical depression, you’ll need to be evaluated by a medical or mental health professional.

If you live in North America, a clinician may use guidelines from The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to inform your MDD diagnosis. This guidebook contains criteria to help professionals appropriately diagnose mental health conditions.

After evaluating your symptoms, a mental health professional will ask you questions to determine whether substance abuse, side effects from a medication, or another mental health condition could be contributing to symptoms. In some cases, you may need to undergo a physical exam or lab tests.

A clinician may want to rule out other depressive and mood disorders, including:

Medical professionals also use questionnaires to see if your symptoms indicate clinical depression. You can take Lemonaid’s questionnaire now for free to find out how you score on the depression scale.

If your score indicates depression, our medical team can work with you to diagnose and treat depression. We’re here for you. Make an appointment for a mental health consultation and get help with depression on your terms.


Work with a healthcare professional to design a treatment plan that best suits your needs. The most effective major depressive disorder treatments usually include some combination of antidepressant medications, talk therapy, and behavioral strategies.

RX drugs

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs are one of the first-line treatments for clinical depression. Not only are SSRIs safe for long-term use, but they’re also non-habit-forming. These meds ensure you have a healthy level of serotonin in your brain. Brand-name SSRI medications include Prozac, Lexapro, Zoloft, Celexa, and Paxil.

Serotonin and norepinephrine reuptake inhibitors (SNRIs)

SNRIs may be recommended to treat major depression, especially if you have chronic pain. These medications balance the levels of 2 neurotransmitters in your brain: serotonin and norepinephrine.

Tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), & tetracyclic antidepressants

Newer antidepressants on the market have mostly replaced these meds. Still, your clinician may consider these older medications if they’ve worked well for family members or if you’ve had trouble treating your symptoms with the newer generation of meds.

Atypical antidepressants

These antidepressant meds are sometimes used to treat major depressive disorder. They include bupropion, mirtazapine, nefazodone, trazodone, and vortioxetine.

Combinations of antidepressants and other medications

Antidepressants may be combined with other meds, such as mood stabilizers or antipsychotics, to treat your unique combination of symptoms.

Visit Lemonaid to talk with a medical professional about your depression and see if prescription medication would be a good fit for your needs.


Therapy is another effective way to treat depression. Mental health professionals often suggest that you include psychotherapy as part of your treatment plan.

Both cognitive behavioral therapy (CBT) and interpersonal therapy work well to treat the symptoms of major depressive disorder.

You can access therapy in many different ways, so you can find the option that works best for you. Therapy is available in one-on-one as in-person or online sessions, via apps, and in group settings.

Behavioral & lifestyle changes

The following behavioral and lifestyle modifications may help to relieve depression symptoms:

  • Exercise to release endorphins.
  • Use meditation to disrupt negative thinking.
  • Sleep at least 7 hours each night.
  • Eat a healthy, balanced diet.
  • Avoid drugs, alcohol, and caffeine.
  • Connect with other people.
  • Don’t be afraid to ask for help.

Alternative treatment protocols

If your clinical depression symptoms do not respond to medication, psychotherapy, or behavioral changes, a mental health clinician may recommend additional treatment modalities.

Electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS) sometimes help patients with severe symptoms that have not responded to standard treatments. ECT and TMS are usually considered a last resort, reserved for patients with life-threatening symptoms.


Major depressive disorder is a medical illness that can cause serious health complications. As with other mental health disorders, clinical depression may interfere with your daily life and cause issues at home, work, school, and other critical parts of your life.

It’s possible to have major depressive disorder that co-occurs with another mental health condition. You may have major depression even if you’ve already been diagnosed with another disorder.

The best way to reduce the impact of major depression on your life is to seek treatment early.

For many people, medication, therapy, behavioral strategies, and lifestyle changes can significantly reduce or even eliminate symptoms. With assistance from your healthcare provider, you can create a customized plan that helps you feel better as quickly as possible.

It can be dangerous to discontinue antidepressant medications abruptly, and the effectiveness of drugs can change over time, so it’s crucial to work closely with a clinician. Once you’ve developed a treatment plan, follow it carefully and be sure to make adjustments with medical guidance.

Although it may take some time to fine-tune your treatment, seeking care is the first step in starting to feel better.


  • Major depressive disorder is a common type of clinical depression.
  • Scientists are still learning about the causes of major depression, which include factors like genetics, hormones, environment, and life experience.
  • Many people manage the symptoms of clinical depression with medication and therapy.
  • Behavioral strategies and lifestyle changes can also help treat depression, especially when combined with medication, therapy, or both.
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Editorial Team


April 27, 2021

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.