Depression is a "whole-body" illness, involving your body, mood, and thoughts. It affects the way you eat and sleep, the way you feel about yourself, and the way you think about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be willed or wished away. People with a depressive illness cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people who suffer from depression. 

The symptoms of depression may vary from person to person, and also depend on the severity of the depression. Depression causes changes in thinking, feeling, behavior, and physical well-being.

• Changes in Thinking - You may experience problems with concentration and decision making. Some people report difficulty with short term memory, forgetting things all the time. Negative thoughts and thinking are characteristic of depression. Pessimism, poor self-esteem, excessive guilt, and self-criticism are all common. Some people have self-destructive thoughts during a more serious depression.
• Changes in Feelings - You may feel sad for no reason at all. Some people report that they no longer enjoy activities that they once found pleasurable. You might lack motivation, and become more apathetic. You might feel "slowed down" and tired all the time. Sometimes irritability is a problem, and you may have more difficulty controlling your temper. In the extreme, depression is characterized by feelings of helplessness and hopelessness.
• Changes in Behavior - Changes in behavior during depression are reflective of the negative emotions being experienced. You might act more apathetic, because that's how you feel. Some people do not feel comfortable with other people, so social withdrawal is common. You may experience a dramatic change in appetite, either eating more or less. Because of the chronic sadness, excessive crying is common. Some people complain about everything, and act out their anger with temper outbursts. Sexual desire may disappear, resulting in lack of sexual activity. In the extreme, people may neglect their personal appearance, even neglecting basic hygiene. Needless to say, someone who is this depressed does not do very much, so work productivity and household responsibilities suffer. Some people even have trouble getting out of bed.
• Changes in Physical Well-being - We already talked about the negative emotional feelings experienced during depression, but these are coupled with negative physical emotions as well. Chronic fatigue, despite spending more time sleeping, is common. Some people can't sleep, or don't sleep soundly. These individuals lay awake for hours, or awaken many times during the night, and stare at the ceiling. Others sleep many hours, even most of the day, although they still feel tired. Many people lose their appetite, feel slowed down by depression, and complain of many aches and pains. Others are restless, and can't sit still.

Now imagine these symptoms lasting for weeks or even months. Imagine feeling this way almost all of the time. Depression is present if you experience many of these symptoms for at least several weeks. Of course, it's not a good idea to diagnose yourself. If you think that you might be depressed, see a psychologist as soon as possible. A psychologist can assess whether you are depressed, or just under a lot of stress and feeling sad. Remember, depression is treatable. Instead of worrying about whether you are depressed, do something about it. Even if you don't feel like it right now. 

Depression is one of the most common psychological problems, affecting nearly everyone through either personal experience or through depression in a family member. Each year over 17 million American adults experience a period of clinical depression. The cost in human suffering cannot be estimated. Depression can interfere with normal functioning, and frequently causes problems with work, social and family adjustment. It causes pain and suffering not only to those who have a disorder, but also to those who care about them. Serious depression can destroy family life as well as the life of the depressed person. 

Impact of Depression:

• Causes tremendous emotional pain
• Disrupts the lives of millions of people
• Adversely affects the lives of families and friends
• Reduces work productivity and absenteeism
• Has a significant negative impact on the economy, costing an estimated $44 billion a year

Depression and bipolar depression are presented separately on this website because of the unique problems encountered with bipolar disorder. Individuals interested in information about bipolar disorder should also review the information on depression, as bipolar disorder usually includes depressive episodes as well.  Bipolar disorder was formerly called manic-depressive disorder. It is a type of depression, and it characterized by the presence of mood swings, especially "manic highs" that often result in high risk, self-damaging behavior.  Most individuals with bipolar disorder have both depressive episodes and hypomanic episodes.

Depression is a psychological condition that changes how you think and feel, and also affects your social behavior and sense of physical well-being. We have all felt sad at one time or another, but that is not depression. Sometimes we feel tired from working hard, or discouraged when faced with serious problems. This too, is not depression. These feelings usually pass within a few days or weeks, once we adjust to the stress. But, if these feelings linger, intensify, and begin to interfere with work, school or family responsibilities, it may be depression.

Depression can affect anyone. Once identified, most people diagnosed with depression are successfully treated. Unfortunately, depression is not always diagnosed, because many of the symptoms mimic physical illness, such as sleep and appetite disturbances. Recognizing depression is the first step in treating it.

Nearly two-thirds of depressed people do not get proper treatment:

• The symptoms are not recognized as depression.
• Depressed people are seen as weak or lazy.
• Social stigma causes people to avoid needed treatment.
• The symptoms are so disabling that the people affected cannot reach out for help. 
• Many symptoms are misdiagnosed as physical problems
• Individual symptoms are treated, rather than the underlying cause.

Clinical depression is a very common psychological problem, and most people never seek proper treatment, or seek treatment but they are misdiagnosed with physical illness. This is extremely unfortunate because, with proper treatment, nearly 80% of those with depression can make significant improvement in their mood and life adjustment.

Causes of Depression:

You may have heard people talk about chemical imbalances in the brain that occur in depression, suggesting that depression is a medical illness, without psychological causes. However, all psychological problems have some physical manifestations, and all physical illnesses have psychological components as well. In fact, the chemical imbalances that occur during depression usually disappear when you complete psychotherapy for depression, without taking any medications to correct the imbalance. This suggests that the imbalance is the body's physical response to psychological depression, rather than the other way around.

Some types of depression do seem to run in families, suggesting a biological vulnerability. This seems to be the case with bipolar depression and, to a lesser degree, severe major depression. Studies of families, in which members of each generation develop bipolar disorder, found that those with bipolar disorder have a somewhat different genetic makeup than those who are not diagnosed.

However, the reverse is not true. Not everybody with the genetic makeup that causes this vulnerability to bipolar disorder develops the disorder. Additional factors, such as stress and other psychological factors, are involved in its onset as well. Likewise, major depression also seems to occur, generation after generation, in some families, but not with a frequency that suggests clear biological causes. Additionally, it also occurs in people who have no family history of depression. So, while there may be some biological factors that contribute to depression, it is clearly a psychological disorder.

A variety of psychological factors appear to play a role in vulnerability to these severe forms of depression. Most likely, psychological factors are completely responsible for other forms of mild and moderate depression, especially reactive depression. Reactive depression is usually diagnosed as an adjustment disorder during treatment. 

People who have low self-esteem, who consistently view themselves and the world with pessimism, or who are readily overwhelmed by stress are more prone to depression. Psychologists often describe social learning factors as being significant in the development of depression, as well as other psychological problems.  People learn both adaptive and maladaptive ways of managing stress and responding to life problems within their family, educational, social and work environments. These environmental factors influence psychological development, and the way people try to resolve problems when they occur. Social learning factors also explain why psychological problems appear to occur more often in family members, from generation to generation.  If a child grows up in a pessimistic environment, in which discouragement is common and encouragement is rare, that child will develop a vulnerability to depression as well.

A serious loss, chronic illness, relationship problems, work stress, family crisis, financial setback, or any unwelcome life change can trigger a depressive episode. Very often, a combination of biological, psychological, and environmental factors are involved in the development of depressive disorders, as well as other psychological problems. When you feel depressed, and don't know where to turn, talk to someone who can help.... a psychologist.