Depression is a mood disorder that can cause a range of emotional and physical problems. It is characterized by persistent feelings of sadness and loss of interest, and can range from mild, temporary episodes to severe and persistent depression. Clinical depression, also known as major depressive disorder or major depression, is the most severe form of depression. It is not the same as depression caused by a loss or medical condition.
Signs of major depression may include feelings of hopelessness, increased irritability, loss of pleasure, difficulty concentrating or sleeping, or thoughts of death or suicide. If you have depression that lasts 2 years or more, it's called persistent depressive disorder. This term is used to describe two conditions formerly known as dysthymia (persistent low-grade depression) and chronic major depression. The criteria for diagnosing depressive episodes in ICD-10 and DSM-IV overlap considerably, but they have some differences of emphasis.
In ICD-10, the patient should have two of the first three symptoms (depressed mood, loss of interest in daily activities, reduced energy) plus at least two of the remaining seven symptoms; while in DSM-IV the patient should have five or more than nine symptoms with at least one of the first two (depression) mood and loss of interest). Both diagnostic systems require that symptoms have been present for at least 2 weeks to make a diagnosis (but may be shorter in ICD-10 if symptoms are unusually severe or fast-onset). In both ICD-10 and DSM-IV, symptoms should result in impaired functioning that increases with the severity of the episode. Table 69 compares the symptoms required in ICD-10 and DSM-IV.
Both ICD-10 and DSM-IV classify clinically important depressive episodes as mild, moderate and severe according to the number, type and severity of symptoms present and the degree of functional impairment. Table 70 shows the number of symptoms required by each diagnostic system, which are less specific than DSM-IV. The ICD-10 prescriptive symptom counting approach tends to use only symptom counting to determine severity. Traditionally, the minimum duration of persistent symptoms for major depression is 2 weeks and for chronic depression (or dysthymia) 2 years. These conventional definitions have been adopted in the absence of solid evidence, as there is only a modest empirical basis for the minimum duration (e.g.
Angst & Merikangas, 200 and none that we could find for the “cut-off” between acute and chronic depression). As with severity, duration is best regarded as a dimension with a lower likelihood of remission with increasing chronicity over a given period of time (Van et al.). Therefore, conventional criteria are considered better as guides than as cut-off points. An influential model of the course of major depression proposes that the onset of an episode of depression consists of a worsening of symptoms on a continuum ranging from depressive symptoms to major depression. The improvement phases with treatment consist of the response (significant improvement) to remission (absence of depressive symptoms) which, if stable for 4 to 6 months, results in a (symptomatic) recovery, meaning that the episode is over (Frank et al.).
After recovery, a new episode of depression is considered a recurrence to distinguish it from a relapse of the same episode. DSM — IV defines complete remission when there has been no symptoms for at least 2 months. For partial remission, complete criteria for a major depressive episode are no longer met, or there are no substantial symptoms, but 2 months have not yet passed. DSM — IV specifies “with full recovery between episodes” if...