Although people often talk about depression as if it were one thing, there are actually several different types of depression, and it is important to understand the distinctions. This article helps define several types of depression, or depressive disorders.
One of the most important distinctions to understand is the difference between depression as a natural and ordinate response to a traumatic or very distressing event. This type of depression resolves naturally in a matter of weeks after the initiating event and considered a normal and expected reaction, not a mental health issue.
When depression is not of this type, then it is considered a diagnosable mental health issue. It may have similar symptoms to reactive depression—feelings of sadness and low mood, changes in eating and sleeping patterns, loss of interest in normal activities and withdrawal, for example—but it continues beyond the point at which one would expect normal depression to resolve.
When depression is a mental health issue, it may exist as a mood disorder or a component of a mood disorder, on the one hand, or in tandem with another disorder. Though the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) from the American Psychiatric Association (APA) and the International Classification of Diseases (ICD-10) from the World Health Organization (WHO) classify these a bit differently, we can see some patterns in the occurrence of depression.
Depressive Disorders
In the first case, the following distinctions can be made:
- A single episode of depression, which may be mild, moderate, or severe, and which may or may not include psychotic features
- Recurring major depression, also called major depressive disorder,, which also may be mild, moderate, or severe, and may or may not include psychotic features
- Chronic depression, also called Dysthymic disorder
- Bipolar disorder, formerly called manic depression, in which patients move between depression (which my be mild, moderate, or severe), normal moods, and manic or hypomanic episodes. Bipolar disorder is divided into two types, labeled I, and II, and Cyclothemia, in which the extremes are hypomania and mild depression.
Other types of depression include postpartum depression.
Disorders Including a Depressive Element
In the second case, depression is found linked to both early-onset and late-onset Alzheimer’s dementia, vascular dementia, and adjustment disorder, according to the DSM-IV-TR breakdown. Dementia refers to a loss of the normal functioning ability of the brain. Adjustment disorder refers to a difficulty in adapting after a period in which a major stress occurs.
According to the ICD-10 breakdown, one finds depression as a substantive part of not only unspecified senile depressed dementia, but also several types of psychosis, schizoaffective disorder, depressive conduct disorder, as well as occurring in post-schizophrenic depression. Psychosis refers to a loss of contact with reality.
Other issues that fit this category are premenstrual dysphoric disorder (PMDD) and seasonal affective disorder (SAD).
Co-Occurring Depression
Besides these issues in which depression is the focus or plays a major part, depression can also co-occur with a separate mental health issue. This is often found to be the case with substance abuse and eating disorders.
Sources
http://apps.who.int/classifications/apps/icd/icd10online/
http://counsellingresource.com/distress/dsm-codes/index.html
http://www.ncbi.nlm.nih.gov/pubmedhealth/