What is the main distinction between major depressive disorder and persistent depressive disorder?

The main distinction between major depressive disorder and persistent depressive disorder lies in the duration and severity of symptoms. Major depressive disorder is characterized by more intense symptoms that significantly impair an individual's ability to function, typically lasting for at least two weeks. In contrast, persistent depressive disorder, formerly known as dysthymia, involves a more chronic form of depression where symptoms are less severe but last for a longer duration, often for two years or more. Individuals with persistent depressive disorder may experience milder depressive symptoms, but because these symptoms last for an extended period, they can still lead to significant impairment. Understanding this difference is crucial for diagnosis and treatment, as the approach may vary depending on the nature and duration of the depressive symptoms experienced by the patient.