Dysthymic disorder is common among unmarried and young persons and in persons with low incomes.
About 50 percent of dysthymic disorder patients experience an insidious onset, not an abrupt onset, of the symptoms before age 25. Dysthymic disorder is not synonymous with minor depressive disorder. The difference between dysthymic disorder and minor depressive disorder is primarily the episodic nature of the symptoms in minor depressive disorder. Between episodes, patients with minor depressive disorder have a euthyrnic mood, whereas patients with dysthymic disorder have virtually no euthymic periods. Dysthymic disorder has shown successful treatment with antidepressants.