Major Depressive Disorder - commonly referred as depression - is an illness that involves the body, mood, and thoughts. It is not to be confused with a passing blue mood - depression can have severe repercussions in the person's way of life. It affects a person's appetite, sleep, and work. It affects relationships and how a person feels about himself. Depression is not a sign of weakness, or a condition that can be willed or wished away. One cannot merely change things in a snap - sans treatment, symptoms can last for days, weeks, months, or even years.

Types of Depression

Depressive Disorder comes in different forms. Three of the most common types of depressive disorders are major depression, dysthymia, and bipolar disorder - it is instructive to note that within these types are variations in the number of symptoms, persistence, and how severe they are.

Major Depression is evidenced by a combination of symptoms that interfere with one's ability to live a normal, productive life. A disabling episode of major depression may occur only once, but it more commonly occurs several times in a person's lifetime.

Dysthymia is a less severe type, but nonetheless keeps one from functioning well. It involves chronic, long-term symptoms that do not disable and leaves one feeling miserable. People suffering dysthymia also experience major depressive episodes some time in their lives.

Bipolar disorder, also called manic-depressive disorder, is not nearly as prevalent as the other forms of depression. It is characterized by cyclical mood changes - severe highs (mania) and severe lows (depression). Mood variations are sometimes rapid and dramatic, but most often are gradual. An individual in the depressed cycle can have any or all of the symptoms of a depressive disorder, and when in the manic cycle, the individual may be overactive and have a great deal of energy. Mania often affects judgment, social behavior, and thinking - which lead to embarrassment and serious problems. Left untreated, mania may worsen into a psychotic state.

Symptoms of Depression

- Appetite and/or weight loss or overeating and weight gain

- Constant feelings of emptiness, irritability, sadness, or tension

- Decreased ability to concentrate or make decisions

- Decreased energy

- Difficulty in remembering

- Fatigue

- Feelings of guilt, helplessness, hopelessness, pessimism, and worthlessness

- Insomnia, early-morning awakening

- Loss of interest or pleasure in activities and hobbies that were enjoyed before, including sex

- Oversleeping

- Persistent physical symptoms that do not respond to treatment, like chronic pain, digestive disorders, headaches

- Restlessness

- Thoughts of death or suicide, sometimes with suicide attempts

Causes of Depression

Depression has no singular cause - it is often a result of a combination of factors. Whatever the cause, depression is not a mere state of mind - it is correlated to physical changes in the brain, and connected to an imbalance of a particular chemical that transports signals in your brain and nerves. These are the neurotransmitters.

Factors Involved in Depression

Family: Genetics play a crucial role in depression. It can run in the family for generations, suggesting that a biological vulnerability can be inherited - often the case in bipolar disorder. Major depression seem to occur generation after generation in some families, but it can also occur in people who have no family history of the illness. Inherited or not, major depressive disorders are often associated with variations in brain function and brain structure.

Pessimistic personality: People with low self-esteem, those who consistently view themselves and the world with negative thoughts, or those who are readily overwhelmed by stress are at a higher risk of becoming depressed. These traits may actually be caused by dysthymia.

Physical conditions: Researches through the years have shown that physical changes in the body can be accompanied by mental changes as well. Serious medical conditions like cancer, heart disease, and HIV can contribute to depression, in part because of the physical stress and weakness they bring. Depression can worsen medical conditions, weakening the immune system and making pain more unbearable. The patient loses desire to care for himself, which leads to more complication. In some cases, depression is a side effect of medications used to treat medical conditions.

Stress and Trauma: Major changes in life - breakup from a relationship, death of a loved one, financial problems - can bring depression. Even positive changes like graduating from school getting married, or starting a new job can cause depression.