Dysthymic disorder
300.4 Dysthymic Disorder
Diagnostic Features
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 (p. 357), a Mixed Episode (p. 362), or a Hypomanic Episode (p. 365) 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).
Specifiers
Age at onset and the characteristic pattern of symptoms in Dysthymic Disorder may be indicated by using the following specifiers:
- Early Onset. This specifier should be used if the onset of the dysthymic symptoms occurs before age 21 years. Such individuals are more likely to develop subsequent Major Depressive Episodes.
- Late Onset. This specifier should be used if the onset of the dysthymic symptoms occurs at age 21 or older.
- With Atypical Features. This specifier should be used if the pattern of symptoms during the most recent 2 years of the disorder meets the criteria for With Atypical Features (see p. 420).
Associated Features and Disorders
Associated descriptive features and mental disorders.
The associated features of Dysthymic Disorder are similar to those for a Major Depressive Episode (p. 352). Several studies suggest that the most commonly encountered symptoms in Dysthymic Disorder may be feelings of inadequacy; generalized loss of interest or pleasure; social withdrawal; feelings of guilt or brooding about the past; subjective feelings of irritability or excessive anger; and decreased activity, effectiveness, or productivity. (Appendix B provides an alternative for Criterion B for use in research studies that includes these items.) In individuals with Dysthymic Disorder, vegetative symptoms (e.g., sleep, appetite, weight change, and psychomotor symptoms) appear to be less common than for persons in a Major Depressive Episode. When Dysthymic Disorder without prior Major Depressive Disorder is present, it is a risk factor for developing Major Depressive Disorder (in clinical settings up to 75% of individuals with Dysthymic Disorder will develop Major Depressive Disorder within 5 years). Dysthymic Disorder may be associated with Borderline, Histrionic, Narcissistic, Avoidant, and Dependent Personality Disorders. However, the assessment of features of a Personality Disorder is difficult in such individuals because chronic mood symptoms may contribute to interpersonal problems or be associated with distorted self-perception. Other chronic Axis I disorders (e.g., Substance Dependence) or chronic psychosocial stressors may be associated with Dysthymic Disorder in adults. In children, Dysthymic Disorder may be associated with Attention-Deficit/Hyperactivity Disorder, Conduct Disorder, Anxiety Disorders, Learning Disorders, and Mental Retardation.
Associated laboratory findings.
About 25%-50% of adults with Dysthymic Disorder have some of the same polysomnographic features that are found in some individuals with Major Depressive Disorder (e.g., reduced rapid eye movement [REM] latency, increased REM density, reduced slow-wave sleep, impaired sleep continuity). Those individuals with polysomnographic abnormalities more often have a positive family history for Major Depressive Disorder (and may respond better to antidepressant medications) than those with Dysthymic Disorder without such findings. Whether polysomnographic abnormalities are also found in those with "pure" Dysthymic Disorder (i.e., those with no prior history of Major Depressive Episodes) is not clear. Dexamethasone nonsuppression in Dysthymic Disorder is not common, unless criteria are also met for a Major Depressive Episode.
Specific Age and Gender Features
In children, Dysthymic Disorder seems to occur equally in both sexes and often results in impaired school performance and social interaction. Children and adolescents with Dysthymic Disorder are usually irritable and cranky as well as depressed. They have low self-esteem and poor social skills and are pessimistic. In adulthood, women are two to three times more likely to develop Dysthymic Disorder than are men.
Prevalence
The lifetime prevalence of Dysthymic Disorder (with or without superimposed Major Depressive Disorder) is approximately 6%. The point prevalence of Dysthymic Disorder is approximately 3%.
Course
Dysthymic Disorder often has an early and insidious onset (i.e., in childhood, adolescence, or early adult life) as well as a chronic course. In clinical settings, individuals with Dysthymic Disorder usually have superimposed Major Depressive Disorder, which is often the reason for seeking treatment. If Dysthymic Disorder precedes the onset of Major Depressive Disorder, there is less likelihood that there will be spontaneous full interepisode recovery between Major Depressive Episodes and a greater likelihood of having more frequent subsequent episodes. Although the spontaneous remission rate for Dysthymic Disorder may be as low as 10% per year, evidence suggests the outcome is significantly better with active treatment. The treated course of Dysthymic Disorder appears similar to that of other Depressive Disorders, whether or not there is a superimposed Major Depressive Disorder.
Familial Pattern
Dysthymic Disorder is more common among first-degree biological relatives of people with Major Depressive Disorder than among the general population. In addition, both Dysthymic Disorder and Major Depressive Disorder are more common in the first-degree relatives of individuals with Dysthymic Disorder.
Differential Diagnosis
See the "Differential Diagnosis" section for Major Depressive Disorder (p. 373). The differential diagnosis between Dysthymic Disorder and Major Depressive Disorder is made particularly difficult by the facts that the two disorders share similar symptoms and that the differences between them in onset, duration, persistence, and severity are not easy to evaluate retrospectively. Usually Major Depressive Disorder consists of one or more discrete Major Depressive Episodes that can be distinguished from the person's usual functioning, whereas Dysthymic Disorder is characterized by chronic, less severe depressive symptoms that have been present for many years. When Dysthymic Disorder is of many years' duration, the mood disturbance may not be easily distinguished from the person's "usual" functioning. If the initial onset of chronic depressive symptoms is of sufficient severity and number to meet full criteria for a Major Depressive Episode, the diagnosis would be Major Depressive Disorder, Chronic (if the full criteria are still met), or Major Depressive Disorder, In Partial Remission (if the full criteria are no longer met). The diagnosis of Dysthymic Disorder can be made following Major Depressive Disorder only if the Dysthymic Disorder was established prior to the first Major Depressive Episode (i.e., no Major Depressive Episodes during the first 2 years of dysthymic symptoms), or if there has been a full remission of the Major Depressive Disorder (i.e., lasting at least 2 months) before the onset of the Dysthymic Disorder.
Depressive symptoms may be a common associated feature of chronic Psychotic Disorders (e.g., Schizoaffective Disorder, Schizophrenia, Delusional Disorder). A separate diagnosis of Dysthymic Disorder is not made if the symptoms occur only during the course of the Psychotic Disorder (including residual phases).
Dysthymic Disorder must be distinguished from a Mood Disorder Due to a General Medical Condition. The diagnosis is Mood Disorder Due to a General Medical Condition, With Depressive Features, if the mood disturbance is judged to be the direct physiological consequence of a specific, usually chronic, general medical condition (e.g., multiple sclerosis) (see p. 401). This determination is based on the history, laboratory findings, or physical examination. If it is judged that the depressive symptoms are not the direct physiological consequence of the general medical condition, then the primary Mood Disorder is recorded on Axis I (e.g., Dysthymic Disorder) and the general medical condition is recorded on Axis III (e.g., diabetes mellitus). This would be the case, for example, if the depressive symptoms are considered to be the psychological consequence of having a chronic general medical condition or if there is no etiological relationship between the depressive symptoms and the general medical condition. A Substance-Induced Mood Disorder is distinguished from a Dysthymic Disorder by the fact that a substance (e.g., a drug of abuse, a medication, or exposure to a toxin) is judged to be etiologically related to the mood disturbance (see p. 405).
Often there is evidence of a coexisting personality disturbance. When an individual's presentation meets the criteria for both Dysthymic Disorder and a Personality Disorder, both diagnoses are given.
Diagnostic criteria for 300.4 Dysthymic Disorder
- Depressed mood for most of the day, for more days than not, as indicated either by subjective account or observation by others, for at least 2 years.Note: In children and adolescents, mood can be irritable and duration must be at least 1 year.
- Presence, while depressed, of two (or more) of the following:
- poor appetite or overeating
- insomnia or hypersomnia
- low energy or fatigue
- low self-esteem
- poor concentration or difficulty making decisions
- feelings of hopelessness
- During the 2-year period (1 year for children or adolescents) of the disturbance, the person has never been without the symptoms in Criteria A and B for more than 2 months at a time.
- No Major Depressive Episode (see p. 356) has been present during the first 2 years of the disturbance (1 year for children and adolescents); i.e., the disturbance is not better accounted for by chronic Major Depressive Disorder, or Major Depressive Disorder, In Partial Remission.
Note: There may have been a previous Major Depressive Episode provided there was a full remission (no significant signs or symptoms for 2 months) before development of the Dysthymic Disorder. In addition, after the initial 2 years (1 year in children or adolescents) of Dysthymic Disorder, there may be superimposed episodes of Major Depressive Disorder, in which case both diagnoses may be given when the criteria are met for a Major Depressive Episode.
- There has never been a Manic Episode (see p. 362), a Mixed Episode (see p. 365), or a Hypomanic Episode (see p. 368), and criteria have never been met for Cyclothymic Disorder.
- The disturbance does not occur exclusively during the course of a chronic Psychotic Disorder, such as Schizophrenia or Delusional Disorder.
- The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).
- The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
Specify if:
- Early Onset: if onset is before age 21 years
- Late Onset: if onset is age 21 years or older
Specify (for most recent 2 years of Dysthymic Disorder):
With Atypical Features (see p. 420)