Within the broader term of "clinical depression" are several different types of depression, which are diagnosed based on their symptoms, duration, and underlying cause.
The increased diagnoses of depression over the past thirty years may, in fact, be due to a growing recognition that it is an emotional disorder which surfaces in a variety of ways. Although the word "depression" is often bandied about among people who are unhappy or disappointed about some of their circumstances, they use it with no real understanding of what clinical depression is.
Genuine clinical depression continues well past the event which may have created the original negative reactions, and robs its sufferers of the capacity for normal functioning. Accompanied by lethargy, unremitting sadness, loss of hope, feelings of failure and inadequacy, clinical depression may lead to eating disorders, alcohol and drug abuse, and in some cases, self-destructive behaviors including cutting and even suicide.
There is, however, a form of clinical depression called Bipolar, or Manic Depression. It
is often misdiagnosed because, of all the types of major depression, it is the only one in which the victims experience episodes of unfounded elation and may even become hyperactive. Because their bouts of sadness are interrupted by these episodes, they do not always look like other clinically depressed people.
Unipolar, or major depression, and bipolar depression are the types of depression often contrasted. People suffering from Bipolar Depression may themselves not realize they are depressed because of their frequent switches from extreme sadness and lassitude to extreme happiness and an overabundance of energy. There are no such fluctuations in Unipolar Depression; its most obvious symptom is the sufferer's continuing sadness and lethargy.
The third of the types of depression, Atypical Depression, is both the most prevalent. It is similar to the Bipolar Depression in that people with Atypical Depression are capable of responding to positive events, but their reactions will be less subdued than those of bipolar sufferers. In this they differ from Unipolar Depression victims, whose negativity is ongoing. But even individuals with Atypical Depression are sad and indifferent the majority of the time.
The fourth of the types of depression is the Dysthymic Disorder, a less severe version of Unipolar Depression recognizable for the length of its duration. Dsythymic Disorder will last for more than two years, and because it continues for so long, the negative attitudes of its sufferers are often dismissed as unattractive personality traits. Because of this, of all the types of depression, Dysthymic Disorder is the one least likely to be diagnosed, and it may affect someone for a lifetime.
The last, and most severe of the different types of clinical depression [http://www.treatdepressionhelp.com/Types_Of_Depression/] is Psychotic Depression, which brings visual and auditory hallucinations in addition to a negative emotional stated and loss of interest in life.