There are many, if not numerous, types of depression.
However most of them can be classified in 10 major categories: Major Depression, Dysthymic Disorder, Depressive Disorder Not Otherwise Specified (NOS), Bipolar I Disorder, Bipolar II Disorder, Cyclothymiacs Disorder, Bipolar Disorder NOS, Substance Induced Mood Disorder, Mood Disorder Due to a General Medical Condition and Mood Disorder NOS.
Major Depressive Disorder
Major Depressive Disorder is a psychological disorder characterized by one or more major depressive episodes without history of Manic, Mixed, or Hypomanic Episodes. Also, the episodes of substance induced mood disorder and mood disorder due to a general medical condition do not count toward a diagnosis of Major Depressive Disorder.
Dysthymic Disorder is a chronic mood disturbance characterized by persistent, recurrent, depressed mood.
The essential feature of Dysthymic Disorder is a chronically depressed mood that occurs for most of the day than not, for at least 2 years. Individuals with Dysthymic Disorder describe their mood as sad or “down in the dumps”.
During periods of depression mood, at least two of the following additional symptoms are present: poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, feelings of hopelessness or worthlessness.
Depressive Disorder Not Otherwise Specified (NOS)
The Depressive Disorder Not Otherwise Specified category includes disorders with depressive features that do not meet the criteria for Major Depressive Disorder, Dysthymic Disorder, Adjustment Disorder with Depressed Mood, or Adjustment Disorder with Mixed Anxiety and Depression Mood.
In other words, when an individual suffers from disorder with depressive features, that cannot be classified into known types of depression, that individual is diagnosed with Depressive Disorder NOS.
Bipolar Disorder is a condition that ranges from pure inertia and depression to extreme excitement and violence (mania). Bipolar Disorder is also called, Manic Depressive Disorder, Manic Depression, Alternating Psychosis, Bipolar Depression, Manic-Depressive Illness, etc.
Bipolar I Disorder
Bipolar I Disorder is a condition that is characterized by the occurrence of one or more manic episodes or mixed episodes. Often, individual that suffer from Bipolar I Disorder, also had one or more major depressive episodes. Episodes of substance induced mood disorder or of mood disorder due to a general medical condition do not count toward a diagnosis of Bipolar I Disorder.
Bipolar II Disorder
The essential feature of Bipolar II Disorder is a clinical course that is characterized by the occurrence of one or more major depressive episodes accompanied by at least one hypomanic episode. The presence of a manic or mixed episode precludes the diagnosis of Bipolar II Disorder.
Cyclothymic Disorder (a milder form of Bipolar Disorder) is a chronic mood disturbance lasting at least two years, characterized by many periods of depression and hypomania in which symptoms are not severe. The periods may be separated by intervals of normal mood lasting for months, and may be intermixed or alternate.
Bipolar Disorder Not Otherwise Specified
The Bipolar Disorder NOS category includes disorders with bipolar features that do not meet criteria for any specific Bipolar Disorder.
Mood Disorder Due to a General Medical Condition
This is one of the most common types of depression found in individuals that suffer from hormonal misbalance due to malfunction of thyroid gland. The essential feature of this disorder is a prominent and persistent disturbance in mood that is judged to be due to the direct physiological effects of a general medical condition.
Substance Induced Mood Disorder
Substance Induced Mood Disorder is characterized by prominent and persistent disturbance in mood that is judged to be due to the direct physiological effects of a substance such as drug or alcohol abuse, a medication, toxin exposure, etc.
The categories numbered and briefly described above are predominantly used by health care professionals. In everyday speech Major Depressive Disorder is called Major depression, Dysthymic Disorder is called Chronic Depression, Alcohol Induced Mood Disorder is called Alcohol Depression and so on.
Also, Major Depressive Disorder with Atypical Features is called, by layman, Atypical Depression; Major Depressive Disorder with Postpartum Onset is called, by non-professionals, Postpartum Depression and so on.
As you can see, for these reasons there are many types of depression and you can find out all about them right here by clicking on the desired link below.