Psychiatrists have attempted to catagorize depression in many ways, but most agree that depressions fall into two broad catagories: Reactive or exogenous depression, which are depressions following an identifiable life trauma or loss; and endogenous depressions in which it is difficult to find an external cause. According to most psychiatrists, at least some endogenous depressions are related in a complex way to changes in some neurotransmitters in the brain. On one view, for example, changes in serotonin levels might both be caused by and be a cause of depression.
In addition, depression can be categorised into unipolar depression and depression as part of Bipolar Disorder.
In particular, Bipolar Disorder appears to have well-documented physical correlates, and responds well to chemical treatment.
It is theorised that unipolar depression and bipolar disorder may be part of a wider bipolar spectrum
Depressions are currently treated, with varying degrees of success, in several ways including: psychotherapy? (including [Freudian therapy]?, cognitive therapy, etc.), [anti-depressant medication]?, and [electroconvulsive treatment]?.
See also: