depressionis the major enemy of health , naow a days .

There are several different types of depression. Often they are distinguished by their prevalent features, duration and severity of symptoms. Most of these kinds of depression are defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM), an American Psychiatric Association publication which describes the standard criteria for different types of psychiatric disorders.

The following three different kinds of depression are distinct depressive disorders described in the DSM. A common criteria is that their symptoms either cause 1) significant distress or 2) impair one’s functioning (e.g. work, school, relationships). Also, these depressive symptoms are not caused by a medical condition or substance (e.g. medicatio                                                                                                     Major Depressive Disorder (also known as Major Depression, Clinical Depression) – A major depressive episode occurs with symptoms that last for most of the day, nearly every day for at least two weeks. A symptom must either be 1) depressed mood or 2) a noticeable decrease in interest or pleasure in all or most activities. At least four (or more) additional symptoms are present:

• significant weight loss / weight gain or decrease / increase in appetite
• difficulty sleeping or increase in sleeping
• excessive movement or slowing down associated with mental tension (observed by others)
• fatigue or loss of energy
• feeling worthless or excessive guilt
• difficulty thinking, concentrating or making decisions
• repeatedly thinking about death or suicide, trying to attempt suicide or having a specific plan to commit suicide

Dysthymic Disorder (or also referred to as Dysthymia) – Nearly constant depressed mood for at least 2 years accompanied by at least two (or more) of the following:

• decrease or increase in eating
• difficulty sleeping or increase in sleeping
• low energy or fatigue
• low self-esteem
• difficulty concentrating or making decisions
• feeling hopeless

Symptoms do not occur for more than two months at a time. Generally, this type of depression is described as having persistent but less severe depressive symptoms than Major Depression.

• Catatonic Depression - (Sub-type of Major Depressive Disorder) – This type of depression is characterized by at least two of the following:
  • Loss of voluntary movement and inability to react to one's environment
  • Excessive movement (purposeless and not in response to one's environment)
  • Extreme resistance to instructions/suggestions or unable/unwilling to speak
  • Odd or inappropriate voluntary movements or postures (e.g. repetitive movements, bizarre mannerisms or facial expressions)
  • Involuntarily repeating someone’s words or movements in a meaningless way

Treatment will differ depending on the type of depression based on its severity and various symptoms. For example, the focus of therapy may vary or differentantidepressants may be prescribed targeting certain symptoms.
Notes:

1. Source - Diagnostic and Statistics Manual of Mental Disorders, 4th Edition