What differentiates major depressive disorder from persistent depressive disorder?

Major depressive disorder (MDD) and persistent depressive disorder (PDD, previously known as dysthymia) are differentiated primarily by the duration and severity of symptoms. Major depressive disorder is characterized by episodes of significant depression that can be quite severe but typically last for a shorter period, often at least two weeks. These episodes are intense and can include symptoms such as overwhelming sadness, loss of interest, and significant impairment in daily functioning.

In contrast, persistent depressive disorder is a chronic form of depression, where symptoms are present most of the day for at least two years in adults (one year in children and adolescents). While the symptoms in PDD may not be as severe as those in MDD, they are more enduring and can significantly impact a person’s quality of life over time.

This context helps clarify why the first choice correctly distinguishes MDD as being episodic and intense in nature, while PDD represents a more prolonged but generally less acute state of depressive symptoms. Furthermore, the other options do not accurately reflect the key clinical distinctions between these two disorders, focusing instead on aspects that do not define their differences.