The essential feature of Dysthymic Disorder is a chronically depressed mood that occurs for most of the day more days than not for at least 2 years (Criterion A). Individuals with Dysthymic Disorder describe their mood as sad or “down in the dumps.” In children, the mood may be irritable rather than depressed, and the required minimum duration is only 1 year. During periods of depressed mood, at least two of the following additional symptoms are present: poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, and feelings of hopelessness (Criterion B). Individuals may note the prominent presence of low interest and self-criticism, often seeing themselves as uninteresting or incapable. Because these symptoms have become so much a part of the individual’s day-to-day experience (e.g., “I’ve always been this way,” “That’s just how I am”), they are often not reported unless directly asked about by the interviewer.
During the 2-year period (1 year for children or adolescents), any symptom-free intervals last no longer than 2 months (Criterion C). The diagnosis of Dysthymic Disorder can be made only if the initial 2-year period of dysthymic symptoms is free of Major Depressive Episodes (Criterion D). If the chronic depressive symptoms include a Major Depressive Episode during the initial 2 years, then the diagnosis is Major Depressive Disorder, Chronic (if full criteria for a Major Depressive Episode are met), or Major Depressive Disorder, In Partial Remission (if full criteria for a Major Depressive Episode are not currently met). After the initial 2 years of the Dysthymic Disorder, Major Depressive Episodes may be superimposed on the Dysthymic Disorder. In such cases (“double depression”), both Major Depressive Disorder and Dysthymic Disorder are diagnosed. Once the person returns to a dysthymic baseline (i.e., criteria for a Major Depressive Episode are no longer met but dysthymic symptoms persist), only Dysthymic Disorder is diagnosed.
The diagnosis of Dysthymic Disorder is not made if the individual has ever had a Manic Episode, a Mixed Episode, or a Hypomanic Episode or if criteria have ever been met for Cyclothymic Disorder (Criterion E). A separate diagnosis of Dysthymic Disorder is not made if the depressive symptoms occur exclusively during the course of a chronic Psychotic Disorder, such as Schizophrenia or Delusional Disorder (Criterion F), in which case they are regarded as associated features of these disorders. Dysthymic Disorder is also not diagnosed if the disturbance is due to the direct physiological effects of a substance (e.g., alcohol, antihypertensive medications) or a general medical condition (e.g., hypothyroidism, Alzheimer’s disease) (Criterion G). The symptoms must cause clinically significant distress or impairment in social, occupational (or academic), or other important areas of functioning (Criterion H).