Definition and characteristic symptoms of Dysthymic Disorder
Dysthymic disorder (dysthymia) is characterised by a chronic level of depressed mood which does not meet criteria for a major depressive illness.
According to the 4th revision of the Diagnostic and Statistical Manual (DSM-IV) of the American Psychiatric Society, adults with dysthymic disorder describe themselves as “sad or down in the dumps”.
In children the mood can be irritable instead of sad. Other frequent symptoms of dysthymic disorder in adults are:
- Feelings of hopelessness and pessimistic outlook
- Poor appetite or overeating
- Insomnia or hypersomnia
- Low drive and energy, fatigue
- Low self esteem.
- Poor concentration
- Difficulty making decisions
The DSM-IV specifies that the depressed mood in dysthymic disorder must last "for most of the day, for more days than not, as indicated either by subjective account or observation by others, for at least two years".
For children and adolescents, this time criterion is reduced to one year. There must never have been a manic episode or a major depressive disorder in the first two years of the dysthymic disorder.
The DSM-IV classifies dysthymic disorder as having two subtypes: early onset occurring before age 21 and late onset occurring after age 21, and there is research evidence to support this distinction. For example, the early onset subtype is more difficult to treat (Sansone and Sansone, 2009).
Chronicity of Dysthymic Disorder
It is only in the last couple of decades that it has been fully recognized that a large percentage of depressive disorders do not occur just once (Klein, 2008).
Between 36 and 47 percent of patients in outpatient settings are “chronically” depressed. In adults for whom the dysthymic disorder has lasted for a number of years, it is sometimes difficult to clinically detect the affective disturbance because the person may have adapted to it over the years and on the surface be functioning “normally”.
In many cases the person with chronic dysthymic disorder assumes that the persistent low self esteem and frequent self criticism are just part of their personality.
In other cases, adults who have been traumatized as children have chronic dysthymic disorder although they appear to be functioning well “on the inside” but experience chronically depressed mood and low self esteem “inside”.
Associated features of Dysthymia
Some additional characteristics frequently found in dysthymic disorder include feelings of inadequacy, anhedonia (generalized loss of interest and pleasure in things that used to be pleasurable), social withdrawal, and guilt feelings.
Dysthymic disorder is sometimes comorbid with major depressive disorder, so much so, that the combination is often referred to as “double depression” (Dunner, 2005).
Other conditions that often comorbid with dysthymic disorder are panic disorder, social phobia disorder, and alcohol use disorders (see Brunello et al for review, 1999).
Persons with dysthymic disorder frequently have an above average prevalence of family members with affective disorders including bipolar disorders. Although dysthymic disorder and chronic fatigue syndrome share some symptoms there are important differences (Brunello et al, 1999).
Associated difficulties in everyday functioning
Although one might think of dysthymic disorder with its predominant subthreshold level of depressive mood as less debilitating than major depressive disorder, it is extremely important both clinically and from a public mental health point of view, to recognize that this is not the case generally (Gureje, 2011).
In his recent review of dysthymic disorder Gureje states “the disorder is associated with elevated risks of suicidal outcomes and comparable levels of disability wherever it occurs. Dysthymic disorder commonly carries a worse prognosis than major depressive disorder and comparable or worse clinical outcome than other forms of chronic depression”.
Lifetime prevalence of Dysthymia
The lifetime prevalence for dysthymic disorder was found to be 2.5% in a large US epidemiological study (Kessler 2005) making it the least prevalent of the mood disorders. It is far outranked by major depressive disorder with a lifetime prevalence of 16.6% and bipolar disorder at 3.9%.
The 2.5% lifetime prevalence for dysthymic disorder found in the national US study is much less that the 5.2% obtained for Chinese Americans in Los Angeles in an earlier study (Takeuchi et al, 1998).
Whether this represents a temporal, regional, or methodological effect is not clear.
There is some evidence that dysthymic disorder is more prevalent in relatively high income countries compared to low and middle-income countries (for review see Gureje, 2011). However several interpretations of this result are possible including the hypothesis that the better general functioning in dysthymic disorder compared to major depressive disorder precludes individuals with dysthymia from even being identified by mental health professionals in low income countries.
Treatments for Dysthymic Disorder
Considering the serious effects of dysthymic disorder on everyday functioning, there has been relatively little research on treatment methods and evaluation (Gureje, 2011).
However there is no doubt that the psychopharmacological approach has indeed been one of the main approaches to treatment of dysthymic disorder.
Brunello et al (1999) in their review state “Antidepressants from different classes, and spanning noradrenergic, serotonergic, as well as dopaminergic mechanisms of action, have been shown to be effective against dysthymic disorder in an average of 65% of cases. This is a promising development because social and characterologic disturbances so pervasive in dysthymic disorder often recede with continued pharmacotherapy”.
However Cuijpers et al (2010) conducted a meta-analysis using 1036 studies on the psychological treatment of depression and dysthymic disorder and found that pharmacotherapy was significantly more effective than psychotherapy alone, although both were effective to a varying degree.
Of importance is their observation that the combined use of pharmacotherapy and psychotherapy gave significantly better results than either one alone. It is to be noted though that this was for a sample containing both depression and dysthymic disorder and further research is necessary to determine if there are any differences in treatment response for the two conditions.
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Baldwin, D. S. (2000). Dysthymic disorder: Options in pharmacotherapy. In K. J. Palmer (Ed.), Managing depressive disorders (pp. 17-28). Kwai Chung, Hong Kong: Adis International Publications.
Brunello, N., Akiskal, H., Boyer, P., Gessa, G. L., Howland, R. H., Langer, S. Z., . . . Wessely, S. (1999). Dysthymic disorder: Clinical picture, extent of overlap with chronic fatigue syndrome, neuropharmacological considerations, and new therapeutic vistas. Journal of Affective Disorders, 52(1-3), 275-290.
Cuijpers, P., van Straten, A., Schuurmans, J., van Oppen, P., Hollon, S. D., & Andersson, G. (2010). Psychotherapy for chronic major depression and dysthymic disorder: A meta-analysis. Clinical Psychology Review, 30(1), 51-62.
Dunner, D. L. (2005). Dysthymic disorder and double depression. International Review of Psychiatry, 17(1), 3-8.
Gureje, O. (2011). Dysthymic disorder in a cross-cultural perspective. Current Opinion in Psychiatry, 24(1), 67-71.
Sansone, R. A., & Sansone, L. A. (2009). Early-versus late-onset dysthymic disorder: A meaningful clinical distinction? Psychiatry, 6(11), 14-17.
Takeuchi, D. T., Chung, R. C.-Y., Lin, K.-M., Shen, H., Kurasaki, K., Chun, C.-A., & Sue, S. (1998). Lifetime and twelve-month prevalence rates of major depressive episodes and dysthymic disorder among Chinese Americans in Los Angeles. The American Journal of Psychiatry, 155(10), 1407-1414.