Depression is a mood disorder in which feelings of loss, anger, sadness, or frustration interfere with everyday life. Depression affects approximately 17 million Americans each year. Everyone at one time or another has felt depressed, sad, or blue. Being depressed is a normal reaction to loss, life’s struggles, or an injured self-esteem. Left undiagnosed and untreated, depression can worsen, lasting for years and causing untold suffering, and possibly even result in suicide.

Causes
Depression seems to be related to a chemical imbalance in the brain that makes it hard for the cells to communicate with one another. Depression also seems to be genetic (to run in families). Depression is caused by Sleep disturbances, Amount of exposure to light, Heredity, Nutritional deficiencies or Serious medical conditions, such as heart attack or cancer.

The primary types of depression include :

Major depression – five or more symptoms must be present; an episode must last at least 2 weeks, but tends to continue for 20 weeks. (A mood disorder is classified as minor depression if less than five depressive symptoms are present for at least 2 weeks.)

Dysthymia – a chronic, generally milder form of depression; symptoms are similar to major depression but more mild in degree.

Atypical depression – depression accompanied by unusual symptoms, such as hallucinations, delusions, and physical rigidity.

Symptoms
These are some of the signs and symptoms of depression that you should be aware of :-

Sadness
Feelings of hopelessness or worthlessness
Difficulty concentrating
Difficulty making decisions
Crying easily or crying for no reason
Aches and pains (such as recurrent headaches)
Sexual problems (for example, decreased sex drive)
A change in appetite causing weight loss or gain
Thoughts of death or suicide

Prevention
Using mind/body techniques, such as biofeedback, meditation, and tai chi, are effective ways to prevent or reduce symptoms associated with depression, Adequate sleep, regular exercise, and a balanced, healthy diet may help prevent depression and diminish symptoms of this mood disorder.

Diet and Lifestyle
Depressive symptoms are exacerbated by nutritional deficiencies.

Avoid coffee, sugar, alcohol, dairy products: Depression has been associated with a high intake of caffeine. If you drink four or more cups of caffeine in a given day, try substituting decaffeinated coffee and soft drinks.
Avoid any processed food, artificial colors, stimulant food, canned foods, smoking, dairy products, meats, eggs, and fish.
Limit your total daily fat intake to 30 percent of your total calories. Try not to consume more than 300 milligrams of cholesterol a day.
Vitamin B1 is necessary for the brain to metabolize carbohydrates. A deficiency of B1 can result in fatigue, irritability, memory lapses, insomnia, loss of appetite, and stomach upset.

Advice
Don’t believe all of your negative thinking.
Avoid drugs and alcohol. Both make depression worse.
Avoid making big life decisions when you’re depressed.
Try not to get discouraged. It will take time for your depression to lift fully.