Dysthymia

Other [subway] passengers showed no outward signs of distress. They appeared to have homes and money and good health, they carried briefcases or bags. … Their faces didn't cave in despair or trouble or strain. But they still had a walled-off look, their brows furrowed, their eyes cast deep into their newspapers or their laps. They looked so dissatified and burdened and checked-out. As if the weight of the world bore down on them, and something vital was missing. The clinical term for this is "dysthymia"―the low-grade feeling that life is unfulfilling. It feels like emptiness. Hunger. Disillusionment. Life is not what you'd hoped. It's a less severe version of what I saw every day on the inpatient ward: alienation, isolation, futility, darkness. And it's what I recognised in my husband and many of our friends. We were young, in our twenties, full of energy and professional drive, committed to living and working in a way that contributed to the world. But sometimes the rush and buzz of our day-to-day felt more like treadmill than calling.

For diagnostic, research, and treatment reasons, a distinction should always be made between the milder dysthymias, atypical and hysteroid depressions, and the more serious major depressive illnesses, with and without melancholic (vegetative) and psychotic features.

A decade ago most psychiatrists would have been puzzled to find a chapter on dysthymia in a book about severe depressive disorders. They would have characterized this chronic form of depression as mild, "minor," or "syndromal."[…]In recent years, research has demonstrated the severity, prevalence, and importance of vogorous antidepressant treatment of dysthymia, justifying its inclusion here among serious mood disorders.

In other patients, the dysthymia may co-occur with but not be causally related to the ADHD (Adler and Cohen 2004).[…]Early studies of adults with ADHD found rates of dysthymia as high as 67%–81% (Wender et al. 1985).

Dysthymia in childhood or adulthood also significantly increases the risk of developing a subsequent major depressive episode.

Involutive depression or bipolar dysthymias must be ruled out.[…]Two characteristics of bipolar dysthymias are distinguishable: first, the bipolar disorders are cyclical in character and develop over several days to several weeks, which is quite different from the sudden and sometimes multiple changes of chronic depression; second, the productive phases of dysthymias are accompanied by a considerable decrease in the duration of sleep, to less than 6 hours per day.