Melancholic depression, or 'depression with melancholic features' is a subtype of major depression characterized by major depressive disorder with the following specific features: anhedonia

Anhedonia

In psychology and psychiatry, anhedonia is defined as the inability to experience pleasure from activities usually found enjoyable, e.g. hobbies, exercise, social interaction or sexual activity....

 (the inability to find pleasure in positive things), severe weight loss, psychomotor agitation or retardation, insomnia with early morning awakenings, guilt. Another feature is diurnal variation, typically with worse symptoms in the morning and improvement at night. Melancholic depression is a particularly severe form of depression. Depression is twice as common in women than it is in men. Major depression is most often genetic. Treatment involves: antidepressants, electroconvulsive therapy

Electroconvulsive therapy

Electroconvulsive therapy , formerly known as electroshock, is a psychiatric treatment in which seizures are electrically induced in anesthetized patients for therapeutic effect. Its mode of action is unknown...

, and supportive psychotherapy, as deeper psychotherapy can not be tolerated. The incidence of melancholic depression has been found to increase when the temperature and/or sunlight are low. Roughly 10% of people with depression suffer from melancholic depression.
According to DSM-IV the Melancholic features specifier may be applied to the following only:

1. Major depressive episode
   Major depressive episode
   A major depressive episode is the cluster of symptoms of major depressive disorder. The description has been formalised in psychiatric diagnostic criteria such as the DSM-IV and ICD-10, and is characterized by severe, highly persistent depression, and a loss of interest or pleasure in everyday...
   
   , single episode
2. Major depressive episode
   Major depressive episode
   A major depressive episode is the cluster of symptoms of major depressive disorder. The description has been formalised in psychiatric diagnostic criteria such as the DSM-IV and ICD-10, and is characterized by severe, highly persistent depression, and a loss of interest or pleasure in everyday...
   
   , recurrent episode
3. Bipolar I disorder
   Bipolar I disorder
   Bipolar I disorder is a mood disorder that is characterized by at least one manic or mixed episode. There may be episodes of hypomania or major depression as well...
   
   , most recent episode depressed
4. Bipolar II disorder
   Bipolar II disorder
   Bipolar II disorder is a bipolar spectrum disorder characterized by at least one hypomanic episode and at least one major depressive episode; with this disorder, depressive episodes can be more frequent and are more intense than hypomanic episodes...
   
   , most recent episode depressed

Causes

The causes of Melancholia are believed mostly due to biological factors, some may have inherited the disorder from their parents. Stressful situations can trigger episodes of Melancholia depression but it is not caused by life changing events. It has also been found that Melancholia is common in people who suffer from bipolar depression I and can also be present in oneself who suffers bipolar depression II. People with psychotic features are also thought to be more susceptible to this disorder. It is common in old age and is usually missed by physicians and the symptoms they show are considered just part of dementia. Yet, it may also be contemporaneous along with dementia in the elderly.