Everyone feels blue or sad, but these feelings are usually transitory and pass within a couple of days. When a person has a depressive disorder, it interferes with daily life, normal functioning, and causes pain for both the person with the disorder and those who care about him or her. Depression is a common but serious illness, and most that experience it need treatment to get better.

Warning signs of depression that may be experienced can include any of these:

• 1. Difficulty sleeping or other disruptions of sleep patterns

• 2. Overwhelming feelings of anxiety and/or sorrow at inappropriate times

• 3. Loss of interest in pastimes formerly enjoyed

• 4. A sensation of hopelessness, lack of self esteem and feelings of guilt

• 5. Fatigue and overall lower energy levels

• 6. Loss of appetite or abnormally large appetite, leading to weight loss or gain

• 7. Suicidal thoughts and recurring thoughts about death

• 8. Irritability, restlessness and short temper

• 9. Difficulty concentrating, remembering details, and making decisions

• 10. Difficulty in maintaining close or romantic relationships

Common complications of depression include:

- Problems with other serious illnesses such as heart disease, diabetes, or cancer
- Migraine headaches
- Severe backache or other pains
- Sexual dysfunction
- Sleep disorders

Some of the more common factors involved in depression are:

Family history. Genetics play an important part in depression. It can run in families for generations.

Trauma and stress. Things like financial problems, the breakup of a relationship, or the death of a loved one can bring on depression. You can become depressed after changes in your life, like starting a new job, graduating from school, or getting married.

Pessimistic personality. People who have low self-esteem and a negative outlook are at higher risk of becoming depressed. These traits may actually be caused by low-level depression (called dysthymia).

Physical conditions. Serious medical conditions like heart disease, cancer, and HIV can contribute to depression, partly because of the physical weakness and stress they bring on. Depression can make medical conditions worse, since it weakens the immune system and can make pain harder to bear. In some cases, depression can be caused by medications used to treat medical conditions.

Other psychological disorders.
Anxiety disorders, eating disorders, schizophrenia, and (especially) substance abuse often appear along with depression.

Methods For Depression Treatment
Depression is not a disease, which you can leave untreated no matter what is the intensity of depression it needs treatment. As depression is a recurrent illness, it is suggested that successful short-term treatment be pooled with ongoing, maintenance therapy. A person suffering from depression can have chronic mental illness that requires medication and psychiatric therapy together

 Documentary sources:

http://www.webmd.com

http://nimh.nih.gov