Major Depressive Disorder
Major depressive disorder is also known as major depression, clinical depression, or unipolar depression. The term unipolar refers to the presence of one pole, or one extreme of mood- depressed mood. This may be compared with bipolar depression which has the two poles of depressed mood and mania (i.e., euphoria, heightened emotion and activity). See the diagnostic criteria below.
Different people are affected in different ways by major depression. Some people have trouble sleeping, they lose weight, and they generally feel agitated and irritable. Others may sleep and eat too much and continuously feel worthless and guilty. Still others can function reasonably well at work and put on a "happy face" in front of others, while deep down they feel quite depressed and disinterested in life. There is no one way that people look and behave when they have major depression. However, most people will either have depressed mood or a general loss of interest in activities they once enjoyed, or a combination of both. In addition they will have other physical and mental symptoms that may include fatigue, difficulty with concentration and memory, feelings of hopelessness and helplessness, headaches, body aches, and thoughts of suicide.
In adults, major depressive disorder affects twice as many women as men. For both genders it is most common in those who are 25-44 years of age, and least common for those over the age of 65. In children, clinical depression affects girls and boys at about the same rate. Within an entire lifetime, major depression will affect 10%-25% of women and 5%-12% of men. At any one point in time, 5%-9% of women and 2%-3% of men are likely to be clinically depressed. Although major depression can occur at any age, the average age for developing the illness seems to be in a person's mid-20's. However, the average age of onset of the condition appears to be decreasing. Those with a parent or sibling who has had major depression may be 1.5 to 3 times more likely to develop the condition than those who do not.
For those who have recurrent episodes of major depression, the course of the illness tends to vary. Some people experience bouts of depression separated by years between episodes in which there are no symptoms. Others may have periods of several episodes. Still others may have more and more occurrences as they age. Some studies have indicated that the more depressive episodes a person experiences, the less time there is between the episodes. Also, the number of episodes a person has had may predict the possibility of having another bout with depression. Of those who have had a single major depressive episode, 50%-60% may develop a second one. About 70% of those who have had two episodes may have a third, and 90% who have had three may have a fourth.
For about two-thirds of those individuals who have a major depressive episode they will recover completely. The other one-third may recover only partially or not at all. People who do not recover completely may have a higher chance of experiencing one or more additional episodes.
It is estimated that 10%-25% of those who develop major depressive disorder have previously had dysthymic disorder, and each year about 10% of those with dysthymic disorder will develop a first major depressive episode. There are some people who have had dysthymia prior to developing major depression. The presence of both conditions at the same time is sometimes called "double depression." Those who are in this situation may have a greater chance of developing additional depressive episodes and have more difficulty fully recovering between the episodes. They may also need to have a longer period of continued care in order to overcome their symptoms.
The development of major depressive disorder may be related to certain medical illnesses. As many as 20%-25% of those who have illnesses such as cancer, stroke, diabetes, and myocardial infarction are likely to develop major depressive disorder sometime during the presence of their medical illness. Managing or treating a medical condition can be more difficulty if a person is also clinically depressed. The prognosis for the medical problem may also be less positive.
It has been shown that other mental health conditions may often co-exist with major depressive disorder. Some of these are alcohol/drug abuse, anxiety and panic disorders, obsessive-compulsive disorder, eating disorders, and borderline personality disorder.
Major depressive disorder should be taken very seriously since up to 15% of those with this condition die by suicide.
Diagnosis of Major Depressive Disorder, Single Episode
Summarized from the Diagnostic and Statistical Manual of Mental Disorders- Fourth Edition, Text Revision
A. The person experiences a single major depressive episode:
B. Another disorder does not better explain the major depressive episode.
- For a major depressive episode a person must have experienced at least five of the nine symptoms below for the same two weeks or more, for most of the time almost every day, and this is a change from his/her prior level of functioning. One of the symptoms must be either (a) depressed mood, or (b) loss of interest.
- Depressed mood. For children and adolescents, this may be irritable mood.
- A significantly reduced level of interest or pleasure in most or all activities.
- A considerable loss or gain of weight (e.g., 5% or more change of weight in a month when not dieting). This may also be an increase or decrease in appetite. For children, they may not gain an expected amount of weight.
- Difficulty falling or staying asleep (insomnia), or sleeping more than usual (hypersomnia).
- Behavior that is agitated or slowed down. Others should be able to observe this.
- Feeling fatigued, or diminished energy.
- Thoughts of worthlessness or extreme guilt (not about being ill).
- Ability to think, concentrate, or make decisions is reduced.
- Frequent thoughts of death or suicide (with or without a specific plan), or attempt of suicide.
- The persons' symptoms do not indicate a mixed episode.
- The person's symptoms are a cause of great distress or difficulty in functioning at home, work, or other important areas.
- The person's symptoms are not caused by substance use (e.g., alcohol, drugs, medication), or a medical disorder.
- The person's symptoms are not due to normal grief or bereavement over the death of a loved one, they continue for more than two months, or they include great difficulty in functioning, frequent thoughts of worthlessness, thoughts of suicide, symptoms that are psychotic, or behavior that is slowed down (psychomotor retardation).
C. The person has never had a manic, mixed, or a hypomanic Episode (unless an episode was due to a medical disorder or use of a substance).
Possible specifiers to describe the episode:
Severity: mild, moderate, severe without psychotic features
Severe With Psychotic Features
In Partial/Full Remission
With Catatonic Features
With Melancholic Features
With Atypical Features
With Postpartum Onset
Major Depressive Disorder, Recurrent:
All of the above criteria apply, except with regard to criteria A there have been two or more major depressive episodes with at least two months in between in which no major depressive episode was present.
The above specifiers also apply with the addition of:
With Seasonal Pattern