Major Depression And Other Unipolar Depressions

This section will focus mainly on Major Depressive Disorder (MDD), commonly referred to as "Major Depression" or simply, "Depression." Other mood-related conditions will be explored, including Bipolar Disorders, Dysthymic Disorder, Anxiety Disorders, Seasonal Affective Disorder, Mood Disorder Due to a General Medical Condition, Substance-Induced Mood Disorders, Premenstrual Dysphoric Disorder, Schizoaffective Disorder, and Personality Disorders. This section will discuss historical understandings of depression, current biological, psychological, and social interpretations, and a range of available treatments. Use the sidebar to explore all of these topics.


  1. Depression is More Than Just Sadness
  2. Depression is Complex and Affects Many Areas of Life
  3. A Continuum of Mood States
  4. Depression Has Widespread Effects
  5. Understanding Depression

Depression is More Than Just Sadness

Woman paranoidEveryone has days where they feel blah, down, or sad. Typically, these feelings disappear after a day or two, particularly if circumstances change for the better. People experiencing the temporary "blues" don't feel a sense of crushing hopelessness or helplessness, and are able, for the most part, to continue to engage in regular activities.

Prolonged anhedonia (the inability to experience pleasure), hopelessness, and failure to experience an increase in mood in response positive events rarely accompany "normal" sadness. The same may be said for other, more intense sorts of symptoms such as suicidal thoughts and hallucinations (e.g., hearing voices). Instead, such symptoms suggest that serious varieties of depression may be present, including the subject of this document: Major Depressive Disorder (MDD) or (more informally), Major Depression.


Depression is Complex and Affects Many Areas of Life

For people dealing with Major Depression, negative feelings linger, intensify, and often become debilitating.

Major Depression is a common yet serious medical condition that affects both the mind and body. It is a complex illness, creating physical, psychological, and social symptoms. Although informally, we often use the term "depression" to describe general sadness, the term Major Depression is defined by a formal set of criteria which describe which symptoms must be present before the label may be appropriately used.

Major Depression is a mood disorder. The term "mood" describes one's emotions or emotional temperature. It is a set of feelings that express a sense of emotional comfort or discomfort. Sometimes, mood is described as a prolonged emotion that colors a person's whole psychic life and state of well-being. For example, if someone is depressed, they may not feel like exercising. By not exercising for long periods of time, they will eventually experience the negative effects of a sedentary lifestyle such as fatigue, muscle aches and pains, and in some cases, heart disease.


A Continuum of Mood States

Many people are puzzled by the term "Unipolar Depression," which is another term for Major Depression. The term "Unipolar Depression" is used here to differentiate Major Depression from the other famous sort of depression, Bipolar (or Manic) Depression, which is a separate illness.

It is helpful to think of mood states as occurring on a continuum. During a particular day or week, people can shift from good (or "up") moods, to bad (or "down") moods, or remain somewhere in the middle ("neutral" mood). A person who experiences significant impairment related to shifting between up and down moods often has Bipolar Disorder (discussed in more detail later). Bipolar Disorder can be envisioned as a seesaw movement back and forth between two poles or mood states ("bi" means "two"). In contrast to people with Bipolar Disorder, people with Major Depression remain on the down mood pole; they do not exhibit mood swings. Because they are stuck on the down or depressed end of the mood continuum; they experience a unipolar ("uni" means "one") mood state.


Depression Has Widespread Effects

Mood disorders rank among the top 10 causes of worldwide disability, and Major Depression appears first on the list. Disability and suffering is not limited to the individual diagnosed with MDD. Spouses, children, parents, siblings, and friends of people experiencing Major Depression often experience frustration, guilt, anger, and financial hardship in their attempts to cope with the suffering of their friend or loved one.

Major Depression has a negative impact on the economy as well as the family system. In the workplace, depression is a leading cause of absenteeism and diminished productivity. Although only a minority of people seek professional help to relieve a mood disorder, depressed people are significantly more likely than others to visit a physician. Some people express their sadness in physical ways, and these individuals may undergo extensive and expensive diagnostic procedures and treatments while their mood disorder goes undiagnosed and untreated. As a result, depression-related visits to physicians account for a large portion of health care expenditures.


Understanding Depression

Although the origins of depression are not yet fully understood, we do know that there are a number of factors that can cause a person to suffer from depression. We also know that people who are depressed cannot simply will themselves to snap out of it. Getting better often requires appropriate treatment. Fortunately, there are a wide array of effective treatments available.

The current section provides an in-depth look at Major Depression by summarizing symptoms and diagnostic criteria, prevalence and course, historical and contemporary understandings of the causes of the illness, and assessment and treatment. Use the sidebar to explore all pages in this section.


This TED Ed video, by Helen M. Farrell, talks about the symptoms, possible causes, and some available treatments for depression: