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).
Who is affected with depression?
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.
Symptoms of depression
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.
Treatment and Prognosis
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.
A major depressive episode is not a disorder in itself, but rather is a description of part of a disorder, most often major depressive disorder or bipolar disorder.
A person who suffers from a major depressive episode must either have a depressed mood or a loss of interest or pleasure in daily activities consistently for at least a 2 week period.
This mood must represent a change from the person’s normal mood; social, occupational, educational or other important functioning must also be negatively impaired by the change in mood. A major depressive episode is also characterized by the presence of 5 or more of these symptoms:
- Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feeling sad or empty) or observation made by others (e.g., appears tearful). (In children and adolescents, this may be characterized as an irritable mood.)
- Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day
- Significant weight loss when not dieting or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day.
- Insomnia (inability to sleep) or hypersomnia (sleeping too much) nearly every day
- Psychomotor agitation or retardation nearly every day
- Fatigue or loss of energy nearly every day
- Feelings of worthlessness or excessive or inappropriate guilt nearly every day
- Diminished ability to think or concentrate, or indecisiveness, nearly every day
- Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing
- A major depressive episode also is generally not diagnosed when the same symptoms could be attributed to Bereavement (normal feelings of sadness after the loss of a loved one).