A disorder defined by daily moderate depression lasting longer than 2 years is known as what?

Dysthymic disorder, also known as persistent depressive disorder, is characterized by a prolonged period of depression that lasts for at least two years in adults (one year in children and adolescents). This disorder involves chronic symptoms that may not be as severe as those seen in major depressive disorder but significantly impact a person's daily functioning and quality of life.

In dysthymic disorder, individuals often experience feelings of hopelessness, low self-esteem, and a lack of energy. Symptoms can fluctuate over time but typically persist for an extended duration, leading to a consistent low mood. This condition stands in contrast to major depressive disorder, which is characterized by more intense depressive episodes that are often shorter in duration.

Other disorders listed have different defining characteristics. Cyclothymic disorder involves periods of hypomanic symptoms and periods of depressive symptoms that don't meet the full criteria for major depression. Seasonal affective disorder is a type of depression that occurs at specific times of the year, typically during the fall and winter months, related to changes in daylight. These distinctions clarify why dysthymic disorder is the correct classification for a disorder characterized by moderate depression lasting longer than two years.