A<unk>  <unk>  is a period characterized by the symptoms of<unk><unk>  disorder. Sufferers primarily have a depressed mood for two weeks or more, and a loss of interest or pleasure in everyday activities, accompanied by other symptoms such as feelings of emptiness, hopelessness, anxiety, worthlessness, guilt, irritability, changes in appetite, problems concentrating, remembering details or making decisions, and thoughts of suicide. Insomnia or hypersomnia, aches, pains, or digestive problems that are resistant to treatment may also be present. The description has been formalized in psychiatric diagnostic criteria such as the DSM-5 and ICD-10. Biological, psychological, and social factors are believed to be involved in the cause of depression, although it is still not well understood. Factors like socioeconomic status, life experience, and personality tendencies play a role in the development of depression and may represent increases in risk for developing a<unk> . There are many theories as to how depression occurs. One interpretation is that neurotransmitters in the brain are out of balance, and this results in feelings of worthlessness and despair. Magnetic resonance imaging shows that brains of people who have depression look different than the brains of people not exhibiting signs of depression. A family history of depression increases the chance of being diagnosed. Emotional pain and economic costs are associated with depression. In the United States and Canada, the costs associated with<unk>  depression are comparable to those related to heart disease, diabetes, and back problems and are greater than the costs of hypertension. According to the Nordic Journal of Psychiatry, there is a direct correlation between<unk>  and unemployment. Treatments for a<unk>  include psychotherapy and antidepressants, although in more serious cases, hospitalization or intensive outpatient treatment may be required.
Major depressive episode
Major depressive disorder
Outline of bipolar disorder
Depression 
Late life depression
Atypical depression
Postpartum psychosis
Postpartum depression