Sadness touches our lives at different times, but usually comes and goes. Depression, in contrast, often has enormous depth and staying power. It is more than a passing bout of "the blues." Depression can leave you feeling continuously burdened and can squash the joy you once got out of pleasurable activities.
When depression strikes, doctors usually probe what's going on in the mind and brain first. But it's also important to check what's going on in the body, since some medical problems are linked to mood disturbances. In fact, physical illnesses and medication side effects are behind up to 15% of all depression cases.
Depression isn't a one-size-fits-all illness. Instead, it can take many forms. Everyone's experience and treatment for depression is different. Effective treatments include talk therapy, medications, and exercise. Even bright light is used to treat a winter-onset depression known as seasonal affective disorder. Treatment can improve mood, strengthen connections with loved ones, and restore satisfaction in interests and hobbies.
New discoveries are helping improve our understanding of the biology of depression. These advances could pave the way for even more effective treatment with new drugs and devices. Better understanding of the genetics of depression could also usher in an era of personalized treatment.
The most prominent symptom of major depression is a severe and persistent low mood, profound sadness, or a sense of despair. The mood change can sometimes appear as irritability. Or the person suffering major depression may not be able to take pleasure in activities that usually are enjoyable.
Major depression is more than just a passing blue mood, a "bad day" or temporary sadness. The mood changes that occur in major depression are defined as lasting at least two weeks but usually they go on much longer — months or even years.
A variety of symptoms usually accompany the mood change, and the symptoms can vary significantly among different people.
Many people with depression also have anxiety. They may worry more than average about their physical health. They may have excessive conflict in their relationships and may function poorly at work. Sexual functioning may be a problem. People with depression are at more risk for abusing alcohol or other substances.
Depression probably involves changes in the areas of the brain that control mood. Nerve cells may be functioning poorly in certain regions of the brain. Communication between nerve cells or nerve circuits can make it harder for a person to regulate mood. These problems may be affected negatively by hormones. An individual's life experience affects these biological processes. And genetic makeup influences how vulnerable any of us is to breakdowns in these functions.
An episode of depression can be triggered by a stressful life event. But in many cases, depression does not appear to be related to a specific event.
Major depression may occur just once in a person's life or may return repeatedly. Some people who have many episodes of major depression also have a background pattern of a milder depressed mood called dysthymia.
Some people who have episodes of major depression also have episodes of relatively high energy or irritability. They may sleep far less than normal, and may dream up grand plans that could never be carried out. The person may develop thinking that is out of step with reality — psychotic symptoms — such as false beliefs (delusions) or false perceptions (hallucinations). The severe form of this is called "mania" or a manic episode. If a person has milder symptoms of mania and does not lose touch with reality, it is called "hypomania" or a hypomanic episode.
If a woman has a major depressive episode within the first two to three months after giving birth to a baby, it is called postpartum depression. Depression that occurs mainly during the winter months is called seasonal affective disorder, or SAD.
Episodes of depression can occur at any age. Depression is diagnosed in women twice as often as in men. People who have a family member with major depression are more likely to develop depression or drinking problems.
Bipolar disorder, which used to be called manic depressive illness or manic depression, is a mental disorder characterized by wide mood swings from high (manic) to low (depressed).
Periods of high or irritable mood are called manic episodes. The person becomes very active, but in a scattered and unproductive way, sometimes with painful or embarrassing consequences.
Postpartum refers to the period immediately after childbirth. When a woman has significant symptoms of depression during this period, she is said to have postpartum depression.
Postpartum depression is not the same as the "baby blues," a much more common condition that affects as many as 85% of new mothers. New moms often are emotionally sensitive and tend to cry easily. The baby blues is uncomfortable, but usually doesn't interfere with functioning as a mother, and it almost always goes away within a few weeks.
Postpartum depression is a different matter. It affects up to 15% of new mothers. It may begin at any time in the first two to three months after giving birth. The mother feels sad or hopeless and sometimes guilty or worthless. She is unable to concentrate and unable to take any interest in anything, even the baby. In some cases, the mother may feel overwhelmed by the baby's needs and become intensely anxious. This may lead to persistent troubling thoughts or obsessions about the baby's well-being and compulsive repetitive actions, such as checking on the baby constantly or phoning the pediatrician repeatedly to ask questions.
Dysthymia, also called dysthymic disorder, is a form of depression. It is less severe than major depression, but usually lasts longer. Many people with this type of depression describe having been depressed as long as they can remember, or they feel they are going in and out of depression all the time.
The symptoms of dysthymia are similar to those of major depression, though they tend to be less intense. In both conditions, a person can have a low or irritable mood, a decrease in pleasure, and a loss of energy. They feel relatively unmotivated and disengaged from the world. Appetite and weight can increase or decrease. The person may sleep too much or have trouble sleeping. He or she may have difficulty concentrating. The person may be indecisive and pessimistic and have a poor self-image.
Symptoms can grow into a full-blown episode of major depression. This situation is sometimes called "double depression" because the second problem (major depressive episode) is superimposed on the usual feelings of low mood. People with dysthymia have a greater-than-average chance of developing major depression.