- Last edited on May 16, 2021
Persistent Depressive Disorder (Dysthymia)
Primer
Persistent Depressive Disorder (PDD) is a mood disorder characterized by a depressed mood that occurs for most of the day, for more days than not, for at least two years (one year for children and adolescents). PDD is a consolidation of DSM-IV diagnosis of chronic major depressive disorder and dysthymic disorder.
Epidemiology
- The 12-month prevalence in the United States is estimated to be 0.5% for persistent depressive disorder.[1]
Prognosis
- PDD often has an early and insidious onset in childhood, adolescence, or early adulthood.
- The disorder, by definition, has a chronic course, and are less likely to resolve, compared to a major depressive disorder episode.[2]
- The presence of high neuroticism, more severe symptoms, worse global functioning, and comorbid anxiety disorders or conduct disorder leads to worse long-term outcomes.
Comorbidity
- Early onset is associated with a much higher likelihood of personality disorders (Cluster B and C) and substance use disorders.[3]
- Compared to individuals with major depressive disorder, individuals are also at greater risk for for anxiety disorders, regardless of age of onset.
Risk Factors
DSM-5 Diagnostic Criteria
Criterion A
Depressed mood for most of the day, for more days than not, as indicated by either subjective account or observation by others, for at least 2
years.
1
year.
Criterion B
Presence, while depressed, of at least 2
of the following:
- Hopelessness
- Energy low or fatigue
- Self-esteem is low
- Sleep decreased (insomnia) or increased (hypersomnia)
- Appetite poor, or overeating
- Difficulty making decisions or poor concentration
Mnemonic
The mnemonicHE'S 2 SAD
can be used to remember the criteria for persistent depressive disorder (dysthymia in DSM-IV).H
- HopelessnessE
- Energy lowS
- Self-esteem2
- 2 years of symptomsS
- Sleep decreasedA
- Appetite poorD
- Difficulty making decisions
The rule of 2
's is another way to remember the criteria:
2
years of depressed mood (1 year in children and adolescents)2
of listed criteria- Any symptom-free period always under
2
months
Criterion C
During the 2
year period (1
year for children or adolescents) of the disturbance, the individual has never been without the symptoms in Criteria A and B
for more than 2
months at a time.
Criterion D
Criteria for a major depressive disorder may be continuously present for 2
years.
Criterion E
There has never been a manic episode or a hypomanic episode, and criteria have never been met for cyclothymic disorder.
Criterion F
The symptoms in Criterion A
are not better explained by schizoaffective disorder, schizophrenia, schizophreniform disorder, delusional disorder, or other specified or unspecified schizophrenia spectrum and other psychotic disorder.
Criterion G
The symptoms are not attributable to the physiological effects of a substance (e.g. - a drug of abuse, a medication) or another medical condition (e.g. - hypothyroidism).
Criterion H
The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
Major depression or Persistent Depressive Disorder?
- Because the criteria for a major depressive episode include
4
symptoms that are absent from the symptom list for persistent depressive disorder (dysthymia), a very limited number of individuals will have depressive symptoms that have persisted longer than2
years but will not meet criteria for persistent depressive disorder. - If full criteria for a major depressive episode have been met at some point during the current episode of illness, they should be given a diagnosis of major depressive disorder.
- Otherwise, a diagnosis of other specified depressive disorder or unspecified depressive disorder is warranted.[6]
Specifiers
Onset Specifier
Specify if:
- Early onset: If onset is before age 21 years.
- Late onset: If onset is at age 21 years or older.
Episode Specifier (for most recent 2 years of persistent depressive disorder)
Specify if (for most recent 2 years of persistent depressive disorder):
- With pure dysthymic syndrome: Full criteria for a major depressive episode have not been met in at least the preceding 2 years.
- With persistent major depressive episode: Full criteria for a major depressive episode have been met throughout the preceding 2-year period.
- With intermittent major depressive episodes, with current episode: Full criteria for a major depressive episode are currently met, but there have been periods of at least 8 weeks in at least the preceding 2 years with symptoms below the threshold for a full major depressive episode.
- With intermittent major depressive episodes, without current episode: Full criteria for a major depressive episode are not currently met, but there has been one or more major depressive episodes in at least the preceding 2 years.
Severity Specifier
- Mild: Few, if any, symptoms in excess of those required to make the diagnosis are present, the intensity of the symptoms is distressing but manageable, and the symptoms result in minor impairment in social or occupational functioning.
- Moderate: The number of symptoms, intensity of symptoms, and/or functional impairment are between those specified for “mild” and “severe.”
- Severe: The number of symptoms is substantially in excess of that required to make the diagnosis, the intensity of the symptoms is seriously distressing and unmanageable, and the symptoms markedly interfere with social and occupational functioning.
Remission Specifier
- In partial remission: Symptoms of the immediately previous major depressive episode are present, but full criteria are not met, or there is a period lasting less than
2
months without any significant symptoms of a major depressive episode following the end of such an episode. - In full remission: During the past
2
months, no significant signs or symptoms of the disturbance were present.
With anxious distress
- Anxious distress is defined as the presence of at least
2
of the following symptoms during the majority of days of a major depressive episode or persistent depressive disorder (dysthymia):- (1) Feeling keyed up or tense
- (2) Feeling unusually restless
- (3) Difficulty concentrating because of worry
- (4) Fear that something awful may happen
- (5) Feeling that the individual might lose control of himself or herself
- Severity:
- Mild:
2
symptoms - Moderate:
3
symptoms - Moderate-severe:
4
or5
symptoms - Severe:
4
or5
symptoms and with motor agitation
With mixed features
- A. At least
3
of the following manic/hypomanic symptoms are present nearly every day during the majority of days of a major depressive episode:- (1) Elevated, expansive mood
- (2) Inflated self-esteem or grandiosity
- (3) More talkative than usual or pressure to keep talking
- (4) Flight of ideas or subjective experience that thoughts are racing.
- (5) Increase in energy or goal-directed activity (either socially, at work or school, or sexually)
- (6) Increased or excessive involvement in activities that have a high potential for painful consequences (e.g. - engaging in unrestrained buying sprees, sexual indiscretions, or foolish business investments)
- (7) Decreased need for sleep (feeling rested despite sleeping less than usual; to be contrasted with insomnia)
- B. Mixed symptoms are observable by others and represent a change from the person’s usual behavior
- C. For individuals whose symptoms meet full criteria for either mania or hypomania, the diagnosis should be bipolar I or bipolar II disorder.
- D. The mixed symptoms are not attributable to the physiological effects of a substance (e.g. - a drug of abuse, a medication, other treatment)
With melancholic features
- A.
1
of the following is present during the most severe period of the current episode:- (1) Loss of pleasure in all, or almost all, activities
- (2) Lack of reactivity to usually pleasurable stimuli (does not feel much better, even temporarily, when something good happens)
- B.
3
or more of the following:- (1) A distinct quality of depressed mood characterized by profound despondency, despair, and/or moroseness or by so-called empty mood,
- (2) Depression that is regularly worse in the morning
- (3) Early-morning awakening (i.e. - at least
2
hours before usual awakening) - (4) Marked psychomotor agitation or retardation
- (5) Significant anorexia or weight loss
- (6) Excessive or inappropriate guilt
With atypical features
This specifier can be applied when these features predominate during the majority of days of the current or most recent major depressive episode or persistent depressive disorder.
- A. Mood reactivity (i.e. - mood brightens in response to actual or potential positive events)
- B.
2
or more of the following:- (1) Significant weight gain or increase in appetite
- (2) Hypersomnia
- (3) Leaden paralysis (i.e. - heavy, leaden feelings in arms or legs)
- (4) A long-standing pattern of interpersonal rejection sensitivity (not limited to episodes of mood disturbance) that results in significant social or occupational impairment
- C. Criteria are not met for “with melancholic features” or “with catatonia” during the same episode
With psychotic features
Delusions and/or hallucinations are present.
- With mood-congruent psychotic features:
- The content of all delusions and hallucinations is consistent with the typical depressive themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment
- With mood-incongruent psychotic features:
- The content of the delusions or hallucinations does not involve typical depressive themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment, or the content is a mixture of mood-incongruent and mood-congruent themes
With catatonia
This specifier can apply to an episode of depression if catatonic features are present during most of the episode.
With peripartum onset
This specifier can be applied to the current or, if full criteria
are not currently met for a major depressive episode, most recent episode of major depression if onset of mood symptoms occurs during pregnancy or in the 4
weeks following delivery.
With seasonal pattern
This specifier applies to recurrent major depressive disorder.
- A. There has been a regular temporal relationship between the onset of major depressive episodes in major depressive disorder and a particular time of the year (e.g. - in the fall or winter). Do not include cases in which there is an obvious effect of seasonally related psychosocial stressors (e.g. - regularly being unemployed every winter).
- B. Full remissions (or a change from major depression to mania or hypomania) also occur at a characteristic time of the year (e.g. - depression disappears in the spring)
- C. In the last
2
years,2
major depressive episodes have occurred that demonstrate the temporal seasonal relationships defined above and no nonseasonal major depressive episodes have occurred during that same period. - D. Seasonal major depressive episodes (as described above) substantially outnumber the nonseasonal major depressive episodes that may have occurred over the individual’s lifetime.
Signs and Symptoms
- Since these symptoms have been part of the individual's day-to-day experience for many years (especially in the case of early onset), patients may not report depressive episodes unless directly prompted (e.g. - “I've always been this way.”)
Screening and Rating Scales
- Cornell Dysthymia Rating Scale is also used, but recently developed.
Pathophysiology
- A number of brain regions (e.g. - prefrontal cortex, anterior cingulate, amygdala, hippocampus) have been implicated in persistent depressive disorder. Possible polysomnographic abnormalities exist as well.
Differential Diagnosis
-
- If there is a depressed mood plus
2
or more symptoms meeting criteria for a persistent depressive episode for2
years or more, then PDD is diagnosed. The diagnosis depends on the2
-year duration, which distinguishes it from episodes of depression that do not last2
years. - If the symptoms meet criteria diagnosis of a major depressive episode at any time during this period, then the diagnosis of major depression should also be noted, but it is coded not as a separate diagnosis but rather as a specifier with the diagnosis of persistent depressive disorder.
- If symptoms currently meet full criteria for a major depressive episode, then the specifier of “with intermittent major depressive episodes, with current episode” would be made.
- If the major depressive episode has persisted for at least a
2
-year duration (i.e. - continuously over the course of 730 days [2 years]!) and is still present, then the specifier “with persistent major depressive episode” is used. - If the major depressive episode criteria are not currently met but there has been at least
1
previous episode of major depression in the last2
years of persistent depressive symptoms, then the specifier of “with intermittent major depressive episodes, without current episode” is used. - If the individual has not experienced an episode of major depression in the last 2 years, then the specifier “with pure dysthymic syndrome” is used.
-
- Depressive symptoms are a common feature in chronic psychotic disorders as well (e.g. - schizoaffective disorder, schizophrenia, delusional disorder). Thus, a separate diagnosis of PDD is not made if the depressive symptoms occur only during the course of the psychotic disorder (including the remission phases).
-
- PDD must be distinguished from a depressive or bipolar and related disorder due to another medical condition. If the history, physical examination, or laboratory findings can attribute the depressive symptoms to a direct pathophysiological effects of a specific medical condition (e.g. - Parkinson's disease, Huntington's disease, stroke, multiple sclerosis), then PDD should not be diagnosed.
-
- A substance/medication-induced depressive or bipolar and related disorder is distinguished from persistent depressive disorder when a substance (e.g. - a drug of abuse, a medication, a toxin) is etiologically related to the mood change.
-
- Often, there is evidence of a coexisting personality disorder in PDD. Thus, both diagnoses may be made.
Investigations
- As clinically indicated.
Treatment
- Medication treatment, or a combination of medication plus psychological treatment is better than psychological treatment alone.[7]
- Most treatment principles follow the treatment for major depressive disorder.