Clinical depression can feel like a black, enveloping cloud that unwelcomingly descends into one’s life and makes everyday activities seem overwhelming and pointless. Often, it can be hard to see beyond this black cloud. Once a person suffers one major depressive episode, they may experience subsequent episodes.

Causes

There is no single known cause of depression. It can result from a genetic predisposition for the disorder, hormonal imbalances, stress and trauma, or the use of mood-altering chemicals. It is a biochemical disorder characterized by a dysregulation of neurotransmitters, which are the chemical messengers used by the brain to produce feelings, moods, and emotions. In addition, the parts of the brain responsible for regulating mood, thinking, sleep, appetite and behavior appear to function abnormally.

Depression is a highly treatable disorder. As with many illnesses, the earlier that treatment can begin, the more effective it is and the greater the likelihood that recurrence can be prevented.

Symptoms of Major Depressive Disorder include:

persistent feeling of sadness, emptiness, or irritability
fatigue or loss of energy
loss of motivation or interest
problems focusing and making decisions
feelings of worthlessness or guilt
changes in sleeping or eating patterns
recurring thoughts of death or suicide

How to Help Yourself if You Are Feeling Depressed:

Depressive disorders make one feel exhausted, worthless, helpless, and hopeless. Such negative thoughts may make some people feel like giving up. It is important to realize that these negative perceptions are part of the depression and typically do not accurately reflect the situation. Negative thinking fades as treatment starts to take effect.

In the meantime:

Set realistic goals and assume a reasonable amount of responsibility.
Break large tasks into small ones and set some priorities.
Maintain good sleep habits.
Try to be with other people and to confide in someone, whom you trust, about how you are feeling; it is usually better than being alone and isolated.
Participate in activities that may make you feel better, such as exercise, going to a movie, volunteering, or participating in social events.
Expect your mood to improve gradually, not immediately. Feeling better takes time.
It is advisable to postpone important decisions until the depression has lifted.
Let your family and friends help you.
Learn to watch for early signs that depression is becoming worse and know how to react when it does.
Avoid alcohol and illegal drugs. These substances can make the depression worse over time, and may also impair your judgment about suicide.
Take medications correctly and learn how to manage side effects.
Visit your physician; some medications and medical conditions (i.e. thyroid disorder) can cause the same symptoms as depression.

If you are thinking about harming yourself, or know someone who is, tell someone who can help immediately.

Call a mental health professional and/or your physician.
Call 911 or go to a hospital emergency room to get immediate help or ask a friend or family member to help you do these things.
Call the toll-free, 24-hour hotline of the National Suicide Prevention Lifeline at 1-800-273-TALK (1-800-273-8255); TTY: 1-800-799-4TTY (4889) to talk to a trained counselor.
Make sure you or the suicidal person is not left alone.

Source: NIMH

Approximately 18.8 million American adults, or about 9.5% of the U.S. population age 18 and older in a given year, have a depressive disorder.

Nearly twice as many women (12%) as men (6.6%) are affected by a depressive disorder each year. These figures translate to 12.4 million women and 6.4 million men in the U.S.

Women between the ages of 25-44 are most often affected by depression with a major cause of depression in women being the inability to express or handle Anger.