What Is Major Depressive Disorder (MDD)?

Medically reviewed by Majesty Purvis, LCMHC
Updated July 25, 2023by BetterHelp Editorial Team
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There are several depressive disorder diagnoses in the DSM-5, but major depressive disorder (MDD) is the most common. Understanding this condition, its symptoms, and possible treatment options can be valuable if you think you or someone you love might be living with it. 

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What Is Major Depressive Disorder? 

Major depressive disorder is a serious depressive disorder, often called "clinical depression." To be diagnosed, an individual must experience symptoms for most days for at least two weeks. Symptoms must also interfere with work, sleep, study, and eating. Major depressive disorder is not the same as bipolar disorder, as it does not involve any periods of high energy and instead involves a persistent low mood. MDD is a treatable mental illness, often through a combination of psychotherapy and medication.

According to the World Health Organization (WHO), approximately 280 million people worldwide experience depression. It is also one of the leading causes of disability and is more common in women than men. However, this statistic may be due to the stigma men experience when seeking support. 

What Are The Symptoms Of Major Depressive Disorder?

Depression often surfaces in the teens, 20s, or 30s. However, it can also happen earlier in childhood or later in middle adulthood. In some cases, people may experience a single period of depression in their lives. 

Symptoms of major depression often don't come and go sporadically. Instead, they are experienced throughout the day, almost every day, for an extended period. When someone experiences a major depressive episode, they may have symptoms like fatigue, social isolation, feelings of worthlessness, and a general sense of hopelessness. 

According to the National Alliance On Mental Illness (NAMI), other common symptoms of depression include the following: 

  • Intellectual impairment
  • Physical impairment
  • Sleeping too often or experiencing insomnia 
  • Feelings of anxiety and restlessness
  • Slow movements and reflexes while speaking, moving, or thinking
  • Difficulty remembering details 
  • Challenges with focusing, concentrating, or making decisions
  • Emotional instability, sadness, or frequent crying
  • Feelings of guilt 
  • Feelings of worthlessness 
  • Irritability and quick anger 
  • Loss of interest in previously enjoyed activities 
  • Appetite changes
  • Suicidal thoughts and urges 

The symptoms experienced during a depressive episode range from mild to severe. When the symptoms are mild, the individual may be able to focus somewhat on everyday tasks, not functioning to their total capacity. However, when experiencing severe symptoms, the individual might struggle to complete any activities, including work, household chores, social responsibilities, and self-care. 

What Causes Major Depressive Disorder? 

Major depressive disorder is a complicated mental illness and can have various causes. According to the National Center For Disease Control and Prevention, the condition may be caused by one or a combination of the following risk factors:

  1. Brain Chemistry: An imbalance of chemicals in the brain like dopamine and serotonin
  2. Genetics: A family history of depression or other mental illness or a history of another mental health diagnosis 
  3. Biology: Noticeable physical differences in the brain 
  4. Hormones: Hormonal changes during pregnancy or for other causes, like taking birth control 
  5. Personality: Some personality traits, like neuroticism, may be more highly associated with depression and other mental illnesses

Some non-biological external factors may increase the chances of MDD, including:

  • Substance use disorders 
  • Low self-esteem
  • Traumatic experiences, including but not limited to abuse or neglect  
  • Medication 
  • Societal stigma due to an identity, like an LGBTQ+ identity 
  • A physical illness
  • Chronic stress
  • Grief due to a loss 

How Is MDD Diagnosed?

To receive an MDD diagnosis, speak to your doctor or a healthcare professional. The doctor may conduct a physical exam if you're looking to rule out a medical condition. 

Once the doctor rules out a physical challenge, they may refer you to a mental health professional for a psychological evaluation. This evaluation can involve discussing your symptoms and behaviors and may include completing a questionnaire. If any of your family members have a history of mental illness, your therapist or psychiatrist might look at what type of mental illness these individuals were diagnosed with. 

Once they have all the information, the mental healthcare professional may offer a diagnosis based on the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published by the American Psychiatric Association. Five or more symptoms of a depressive episode lasting at least two weeks are needed to diagnose MDD.

What Is MDD With Psychotic Features? 

Depending on your circumstances and symptoms, you might be diagnosed with a specific type of depression called MDD with psychotic features, also known as psychotic depression.

Psychotic depression is a subtype of MDD and can have severe symptoms. It can be essential to seek emergency medical attention when psychosis is present because it's an illness that a professional can best monitor. 

When diagnosed with psychotic depression, you may have the above symptoms of MDD in conjunction with psychotic symptoms like a loss of reality. In addition to auditory or visual hallucinations, an individual might experience: 

  • Hypochondria
  • Insomnia
  • Physical immobility
  • Anxious or agitated behavior
  • A desire to harm themselves or others 

MDD with psychotic features is divided into two types, including: 

  1. Mood-Congruent Psychotic Features: With this condition, hallucinations or visions experienced by the client revolve around depressing themes. For example, the hallucinations might include guilt and worthless or a preoccupation with death.
  2. Mood-Incongruent Psychotic Features: With this condition, hallucinations are unrelated to the client's mood and may be contradictory to experiences of depression. The symptoms for this type of MDD overlap with schizophrenia and may be much harder to recover from.

When experiencing delusions, the individual might fully believe what they see or hear and may attempt to harm themselves or complete an impossible or risky task. For this reason, receiving immediate support and following a treatment plan may be crucial. 

There is no scientific or medical reason why some people develop psychosis, but genetics and a family history of mental illness may be linked. Stress can also be a factor that leads to a chemical imbalance in the brain. Coping mechanisms for stress, such as exercise, meditation, and therapy, can help prevent and manage these imbalances.

How To Treat MDD

There are several approved treatments for MDD, including the following: 

  • Psychotherapy: Cognitive-behavioral therapy (CBT), interpersonal psychotherapy (IPT), mindfulness-based cognitive therapy (MBCT) 
  • Antidepressant Medication: Consult a medical professional to determine the most effective medication for you 
  • Combination: Medication, therapy, and other psychological services received simultaneously 
  • Treatment-Resistant Approaches: If your depression is not responding to the above methods, you might be recommended for treatment-resistant options like transcranial magnetic stimulation (TMS) for depression 

Treatment for depression is often highly effective, although it may take six weeks or more to see results. However, some people struggle to reach out for help due to a personal choice, the stigma of mental illness, or a lack of resources, trained providers, and care.

When left untreated, depression can lead to other serious complications, including physical health complications and difficulty maintaining relationships with family and friends, leading to loneliness. 

Do You Have Difficulty Overcoming Your Sadness?

Counseling Options 

It is not your fault if you have been diagnosed with depression or believe you may be living with this condition. Depression can affect anyone at any stage of life, and you can reach out for support anytime. Depression is one of the most manageable and treatable mental illnesses for many, and with a combination approach to treatment, many clients find symptom remission. 

If you're ready to start treatment, consider online therapy. Some people with depression find it challenging to get out of bed, and driving to a therapist's office might seem overwhelming. With online therapy through a platform like BetterHelp, you can attend treatment sessions from the comfort and safety of home. In addition, on the days you're not feeling up to therapy, you can choose between phone, video, or chat sessions, allowing you to chat with your therapist through messages instead of opening up a call. 

Research shows that online therapy is effective, too. One study concluded that online therapy resulted in "clinically meaningful improvements in depression and anxiety scores relative to a baseline observed post-intervention at 12 weeks and sustained at program month six." 


MDD is a serious mental health condition characterized by an extended period of intense sadness, lethargy, and loss of interest that can severely impact a person's ability to function in their daily life. MDD is treatable, and a combination approach to care may be most effective. If you're ready to learn how depression treatment might support you, consider contacting a licensed therapist for consultation.

Depression is treatable, and you're not alone

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