Final answer:
Dysthymic disorder, or dysthymia, is a mood disorder with persistent depressive symptoms that last for at least two years. It is less intense than major depressive disorder but can lead to significant daily impairment. Treatment options include psychotherapy and antidepressants.
Step-by-step explanation:
Dysthymic disorder, also known as dysthymia, is characterized by b) Persistent depressive symptoms lasting for at least two years. Dysthymia is one of the mood disorders that causes individuals to experience a consistently low mood over a prolonged period, distinguishing it from the sometimes transient sadness that everyone experiences. Unlike the severe mood swings observed in bipolar disorder, or the seasonal patterns of Seasonal affective disorder (SAD), dysthymia's hallmark is a steady, chronic state of depression.
It's important to note that while major depressive disorder (MDD) includes episodes of severe depression, dysthymia is typically less intense, but its chronic nature can nevertheless lead to significant impairment in day-to-day functioning. The course of dysthymia can be complex and is often influenced by genetic and environmental factors. Although it is a long-term condition, effective treatments, such as psychotherapy and antidepressants, are available to help manage the symptoms.