Dysthymic Disorder (also called dysthymia) refers to a disorder in which the patients have for many years suffered under a slightly depressed mood. In addition to the depressive mood the patients suffer from symptoms such as decreased appetite or increased appetite, insomnia or excessive sleepiness, loss of energy or fatigue, low self-esteem, poor concentration, poor decision-making ability and a sense of hopelessness.
The International Classification of Diseases (ICD-10) defines dysthymia (F34.1) as a disorder in which individuals have suffered for several years in the majority of days of a depressive mood, and which, regarding the severity and duration of the symptoms, is not meeting the criteria for major depressive disorder (ICD-10 F33).
The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) defines the dysthymic disorder (DSM-IV 300.4) as a disorder in which individuals have for a period of at least two years (in children / adolescents at least one year) for most of the day more than half of all days suffered of a depressive mood.
In addition to the depressive mood the patients suffer in the same period of at least two of the following symptoms:
Decreased appetite or increased appetite;
Insomnia or excessive sleepiness;
Loss of energy or fatigue;
Poor concentration and decision making;
Feeling of hopelessness.
During the 2-year-period, no consistent interval for two months or longer without the depressive symptoms must occur.
During the first two years of dysthymic disorder (in children / adolescents one year) at no time an episode of a major depression must have occurred. In the later course of dysthymic disorder “superimposed episodes” of major depressive disorder may occur, in this case the diagnosis is “dysthymic disorder with superimposed episodes of major depression”.
Previous to the dysthymic disorder no manic, mixed or hypomanic episode must have occurred, and the criteria for cyclothymic disorder must not have been met. The symptoms must not occur exclusively in the course of a chronic psychotic disorder. The symptoms must not occur due to the direct physical effects of a substance (such as drugs) or because of a physical illness.
The symptoms must not cause a clinically significant distress or impairment in social, occupational or other important areas of functioning.
Double depression refers to a dysthymia, which is superimposed by an episode of major depressive disorder. The double depression corresponds to the DSM-IV diagnosis of “dysthymic disorder with superimposed episodes of major depression”.
The term neurotic depression (also called depressive neurosis) was and is particularly evident in psychoanalytic parlance, used to distinguish depressive illnesses which developed primarily reactive of the so-called psychotic depression (also called endogenous depression or melancholy).
The neurotic depression is characterized by a persistent depressed mood, while the psychotic depression is characterized mostly by recurrent episodes, probably with intermittent manic episodes.
While the diagnosis of “neurotic depression” was still present in the ICD-9, in the ICD-10 it was replaced by the diagnosis “dysthymia” and “recurrent depressive disorder”. This led to considerable criticism because, according to some opinions, the latter diagnoses do not adequately capture the concept of neurotic depression.
The dysthymia occurs with a point prevalence of approximately 3% and a lifetime risk of about 6%. The onset is often in adolescence. In contrast to the major depressive disorder there is no gender difference in the frequency of occurrence.
The treatment of dysthymia has not been studied as extensively as for example the treatment of major depressive disorder. Overall, the treatment of dysthymia is in many areas similar to the treatment of major depression.
Scientific studies have proved in particular the effectiveness of the so-called cognitive behavioral therapy, the interpersonal therapy, the so-called Cognitive Behavioral Analysis System of Psychotherapy (CBASP) as well as of drug treatment, such as the use of amisulpride or sertraline. The best long-term therapeutic success seems likely with a combination treatment of psychotherapy and medication (cf. Ravindran 1999, Browne 2002).