double depression
a condition in which a person with dysthymic disorder—chronically low or irritable mood—experiences a concurrent major depressive episode. Symptoms commonly include hopelessness, low internal locus of control, low self-esteem, difficulty sleeping, and anhedonia. Severe hopelessness in particular has been implicated as the key distinguishing feature of double depression. Other distinctions (e.g., from dysthymic disorder alone, minor depressive disorder, single-episode depression), however, are more controversial among researchers and practitioners. Some claim that there are few if any legitimate clinical differences between double depression and other depressive conditions, whereas others argue that individuals with double depression have more severe symptoms, greater comorbidity, greater psychopathology in first-degree relatives, and a poorer prognosis; are less responsive to psychotherapy and other
treatment; and otherwise differ in psychosocial functioning, family history, and degree of impairment.