What defines a major difference between persistent depressive disorder and major depressive disorder?

The key distinction between persistent depressive disorder (formerly known as dysthymia) and major depressive disorder lies in the duration of symptoms. Persistent depressive disorder is characterized by a chronic depressed mood that lasts for at least two years in adults (one year in children and adolescents), whereas major depressive disorder involves discrete episodes of depression that can last for a duration of at least two weeks but do not have to be chronic.

This chronic nature of persistent depressive disorder often means that individuals experience a more consistent and prolonged impact on their mood and functioning, while those with major depressive disorder may have periods of normal mood interspersed between episodes of significant depression. Understanding this difference is crucial for diagnosis and treatment, as the approaches may vary significantly based on whether a patient is experiencing a chronic condition or episodic episodes of depression.