What’s the Difference Between Major Depressive Episode and Major Depressive Disorder?

I think a lot of people are having trouble differentiating between a Major Depressive Episode and Major Depressive Disorder.  In this article, I will try to clearly explain the difference between the two.

Both Major Depressive Episode (MDE) and Major Depressive Disorder (MDD)  are legitimate DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition) Asix I diagnoses.  The main difference to take away from this article is that Major Depressive Episode is a common set of symptoms that is subsumed in Major Depressive Disorder.  However, the main difference in Major Depressive Episode and Major Depressive Disorder is chronicity and causality.  With a Major Depressive Episode, the symptoms are caused by socio-economic factors (such as loss of job or divorce)  and subside once the stressor is no longer there.  Typically,  Major Depressive Episode will subside within 6 months, sometimes a lot shorter.  MDE often ends spontaneously as the person learns to come to terms with the stressor or learns to adapt.

In order to be a valid Axis I DSM-IV diagnosis, the patient must present five of the following symptoms that lasts at least two weeks to be diagnosed with Major Depressive Episode:

  • Depressed mood/flattened affect
  • Loss of interest
  • Markedly decreased or increase in weight caused by decrease/increase in appetite
  • Chronic sleep impairment marked by hypersomnia or insomnia
  • Lethargic in mannerism and behavior and motor activity is agitated or slow
  • Extreme fatigue and always tired
  • Lack of self-worth
  • Marked decrease in concentration, decision-making abilities, and cognition
  • Thought of self-harm or suicidal ideation (although acting on it is not required)

As previously noted, these symptoms are also present in those diagnosed with Major Depressive Disorder, which is the perfect segway into talking about Major Depressive Disorder.

Unlike Major Depressive Episode, MDD is marked by chronic depression with symptoms lasting for as much as the whole life of the person.  Additionally, MMD frequently occurs with other psychiatric problems, such as Bipolar Disorder or Anxiety Disorder.  Those with MDD have an increased risk of heart disease.  Like Major Depressive Episode, socio-economic factors can play a role in the development of Major Depressive Disorder.  However, unlike Major Depressive Episode, MDD can be caused by biological factors (such as the lack of the serotonin transporter).  Heredity is also a strong indicator of Major Depressive Disorder as those with a family history of depression are more at-risk of developing Major Depressive Disorder.

The DSM-IV-TR recognizes five subtypes of Major Depressive Disorder.  The five types are:

  1. Melanchonic depression
  2. Atypical depression
  3. Catatonic depression (the most severe kind of depression)
  4. Postpartum depression
  5. Seasonal affective disorder (SAD)

Prevalence and Prognosis for MDD and MDE

It is estimated that almost 300 million people are suffering from depression worldwide as of 2010.  The amount of people suffering from depression at any one time is about 17 percent in the United States.  Those in their 20s are at the highest risk of developing depression (both in the form of MDD and MDE) and those over the age of 65 have the lowest risk.  Symptoms in those with MDE usually subside within six months but some episodes do last for years if the episode is severe and left untreated.  MDD can subside with medication and psychotherapy or it can last for the rest of a person’s life depending on the severity and effectiveness of treatment.

In conclusion, a person can be diagnosed with Major Depressive Episode without being Diagnosed with Major Depressive Disorder, as a Major Depressive Episode doesn’t necessarily mean that the person has chronic clinical depression.  However, those who are diagnosed with Major Depressive Disorder will invariably have episodes of depression.

Disclaimer: This article is for informational purposes only.  In order to be properly diagnosed and treated for your mental disorder(s), you should seek assistance from a trained medical professional.


1. http://www.ncbi.nlm.nih.gov/pubmed/12830306?dopt=Abstract

2. http://ajp.psychiatryonline.org/article.aspx?articleID=176973&RelatedWidgetArticles=true

3. http://depression.org

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