What Is Depression?
Depression (major depressive disorder) is a common and serious medical illness that negatively affects how you feel, the way you think and how you act. Fortunately, it is also treatable. Depression causes feelings of sadness and/or a loss of interest in activities you once enjoyed. It can lead to a variety of emotional and physical problems and can decrease your ability to function at work and at home.
Depression symptoms can vary from mild to severe and can include:
Feeling sad or having a depressed mood
Loss of interest or pleasure in activities once enjoyed
Changes in appetite — weight loss or gain unrelated to dieting
Trouble sleeping or sleeping too much
Loss of energy or increased fatigue
Increase in purposeless physical activity (e.g., inability to sit still, pacing, handwringing) or slowed movements or speech (these actions must be severe enough to be observable by others)
Feeling worthless or guilty
Difficulty thinking, concentrating or making decisions
Thoughts of death or suicide
Symptoms must last at least two weeks and must represent a change in your previous level of functioning for a diagnosis of depression.
Also, medical conditions (e.g., thyroid problems, a brain tumor or vitamin deficiency) can mimic symptoms of depression so it is important to rule out general medical causes.
Depression affects an estimated one in 15 adults (6.7%) in any given year. And one in six people (16.6%) will experience depression at some time in their life. Depression can occur at any time, but on average, first appears during the late teens to mid-20s. Women are more likely than men to experience depression. Some studies show that one-third of women will experience a major depressive episode in their lifetime. There is a high degree of heritability (approximately 40%) when first-degree relatives (parents/children/siblings) have depression.
Depression Is Different From Sadness or Grief/Bereavement
The death of a loved one, loss of a job or the ending of a relationship are difficult experiences for a person to endure. It is normal for feelings of sadness or grief to develop in response to such situations. Those experiencing loss often might describe themselves as being “depressed.”
But being sad is not the same as having depression. The grieving process is natural and unique to each individual and shares some of the same features of depression. Both grief and depression may involve intense sadness and withdrawal from usual activities. They are also different in important ways:
In grief, painful feelings come in waves, often intermixed with positive memories of the deceased. In major depression, mood and/or interest (pleasure) are decreased for most of two weeks.
In grief, self-esteem is usually maintained. In major depression, feelings of worthlessness and self-loathing are common.
In grief, thoughts of death may surface when thinking of or fantasizing about “joining” the deceased loved one. In major depression, thoughts are focused on ending one’s life due to feeling worthless or undeserving of living or being unable to cope with the pain of depression.
Grief and depression can co-exist For some people, the death of a loved one, losing a job or being a victim of a physical assault or a major disaster can lead to depression. When grief and depression co-occur, the grief is more severe and lasts longer than grief without depression.
Distinguishing between grief and depression is important and can assist people in getting the help, support or treatment they need.