Dysthymic depression, also known as persistent depressive disorder, is a mood disorder characterized by chronic feelings of sadness, hopelessness, and low self-esteem. Synonyms for dysthymic depression include chronic depression, melancholic depression, and low-grade depression. Other related terms include subthreshold depression and minor depression, which refer to milder forms of depression with fewer symptoms. Additionally, atypical depression describes a subtype of depression that presents with different symptoms than traditional depression, such as increased appetite and hypersomnia. Regardless of the specific terminology used, treating dysthymic depression may involve a combination of therapy, medication, and lifestyle changes to help alleviate symptoms and improve overall quality of life.