ICD-116A72	DYSTHYMIC DISORDER Dysthymic disorder
ICD-10F34.1	Dysthymia
DSM-5-TRF34.1	Persistent Depressive Disorder

1. Definition and nosology

Dysthymic disorder (ICD-11: 6A72 Dysthymic Disorder; DSM-5-TR: Persistent Depressive Disorder — F34.1) — chronic depressive symptoms lasting at least 2 years (in adults; 1 year in children/adolescents) that do not meet the severity of a major depressive episode. The patient may describe their state as 'I've always been this way'.

DSM-5-TR — the term “Persistent Depressive Disorder” combines dysthymia and chronic major depressive disorder; ICD-11 codes dysthymic and chronic depressive episode separately.

2. History

• Flemming C.F. (1844) — first psychiatric use of the term “dysthymia”; Kahlbaum (1882) — gave it its modern meaning as a chronic, subthreshold depressive state.
• Akiskal H.S. (1980s) — dysthymic temperament as a substage of the depressive spectrum.
• DSM-III (1980) — official diagnosis “Dysthymic Disorder”.
• DSM-5 (2013) — “Persistent Depressive Disorder” — merger of dysthymia and chronic MDD.
• ICD-11 (2019) — dysthymic disorder retained separately.

3. Epidemiology

• Lifetime prevalence: 1.1–6.4% (dysthymia); 12-month prevalence in the US ~0.5%, plus 1.5% for chronic major depression (DSM-5-TR).
• Sex: 2 times higher in females.
• Onset: early (childhood/adolescence — early-onset; ≥ 21 years — late-onset).
• “Double depression” — major depressive episode on a background of dysthymic disorder — occurs in 76.9% of patients within 5 years (Klein D.N. et al. Am J Psychiatry 2000;157(6):931–939).
• Comorbidity: anxiety, BPD, substance use.

4. Aetiology and pathogenesis

• Shared genetic and neurobiological predisposition with major depressive disorder.
• Childhood trauma and chronic psychosocial stress are key environmental risk factors.
• The frequency of depressive disorder or dysthymia is increased in close relatives.

5. Clinical features

• Persistent low mood — present most of the time (≥ half the time, no symptom-free period > 2 months over 2 years).
• At least 2 of the following: low or increased appetite, insomnia or hypersomnia, low energy, low self-esteem, concentration difficulty, hopelessness.
• The patient has adapted to numerous functional compromises — the explanation “I have always been like this” is typical; they often present to the clinic against a background of a major depressive episode.

6. Diagnosis

6.1 Unified diagnostic criteria

A. Persistent depressive mood ≥ 2 years (children ≥ 1 year), most of the day, most of the time.

B. ≥ 2 symptoms during depressive episodes (above)

C. No symptom-free period longer than 2 months within 2 years (1 year).

D. During this period, criteria for a major depressive episode may be continuously present (DSM-5 — new “double depression” synthesis).

E. Never had a manic or hypomanic episode.

F. Not better explained by schizoaffective or other psychotic disorder.

G. Exclusion of substance or medical condition.

H. Significant distress or functional impairment.

6.2 Source-specific clarifications

• DSM-5-TR: “Persistent Depressive Disorder” — combines dysthymia and chronic MDD; qualifiers — early/late onset, with/without anxious distress, melancholic, atypical, peripartum, seasonal, etc.
• ICD-11: dysthymic disorder (6A72) separate; chronic depressive episode within 6A70/71 qualifier.

6.3 Diagnostic algorithm

1. Clinical interview + long-term history (patient may not recall exact onset).
2. SCID-5; PHQ-9, HAM-D, MADRS.
3. Bipolar screening.
4. Personality assessment – differential with BPD.
5. Medical and laboratory (thyroid, anemia, B12).

6.4 Differential diagnosis

7. Examination and assessment

• PHQ-9, HAM-D, MADRS.
• Cornell Dysthymia Rating Scale — dysthymia-specific.
• Medical and laboratory.

8. Treatment

1. Pharmacotherapy: SSRI (sertraline, fluoxetine) — first-line; the effect may take 6–8 weeks (slower than in major depression).
2. Psychotherapy: CBASP (Cognitive Behavioral Analysis System of Psychotherapy — McCullough J.) — specifically developed for chronic depression; CBT, IPT.
3. Combination — superior to monotherapy in dysthymic disorder (Keller M.B. et al. NEJM 2000 – nefazodone + CBASP RCT).
4. In “double depression” — The management includes acute treatment of a major depressive episode + long-term maintenance therapy.
5. Refractory — medication switch, augmentation (lithium, atypical antipsychotic).

Source-specific specifications

• NICE NG222 — recommends long-term cognitive behavioural treatment for chronic depressive symptoms (CBASP is not named in the guideline); CBASP is named by APA 2010.
• APA 2010 — combination superior.
• Keller M.B. et al. NEJM 2000 — nefazodone + CBASP combination significantly superior to monotherapy.

Treatment methods

1. Cognitive Behavioral Analysis System of Psychotherapy (CBASP — Cognitive Behavioral Analysis System of Psychotherapy) — McCullough (McCullough J.) — Approach specifically developed for chronic depression — situation analysis, interpersonal behavior teaching, use of therapeutic relationship as main tool. Keller M.B. et al. NEJM 2000 RCT.
2. SSRI long-term — Sertraline, fluoxetine, escitalopram; slow response; prolonged maintenance.
3. CBT and IPT — Standard depression therapies; modified for chronic form.

9. Prognosis

• Chronic course; spontaneous remission is rare.
• “Double depression” — develops in 76.9% of dysthymic patients without a prior major episode within 5 years (Klein D.N. et al. Am J Psychiatry 2000).
• Functional level improves with long-term treatment.
• Monitoring — periodic scales, compliance, comorbidity.

10. Myths and misconceptions

Myth 1: “Dysthymia is just a ‘gloomy character’, not a medical disorder”

Evidence: persistent functional impairment, suicidality risk, development of “double depression”; should be evaluated as a medical disorder.

Myth 2: “Dysthymic patient does not respond to antidepressants”

Evidence: The response is slow — 6 to 8 weeks, but SSRIs are effective; combination with CBASP superior.

Myth 3: “Chronic depression only requires psychotherapy; medications are ineffective”

Evidence: Keller NEJM 2000 — nefazodone + CBASP combination superior to monotherapy; pharmacotherapy is a core component.

Myth 4: “The patient's explanation 'I've always been like this' is not a basis for diagnosis — it should be accepted as adaptation”

Evidence: This patient perspective creates a problem of under-detection — long-term functional compromise may be a marker of medical condition.

Myth 5: “Herbal preparations are a safe alternative for dysthymia”

Evidence: St John's Wort demonstrates some efficacy in mild depression, but CYP induction interactions; standard antidepressants superior.

11. Sources

1. WHO. ICD-11. 6A72 Dysthymic disorder. 2024.
2. APA. DSM-5-TR. 2022.
3. NICE NG222. 2022.
4. Keller M.B., McCullough J.P., Klein D.N. et al. A comparison of nefazodone, the cognitive behavioral-analysis system of psychotherapy, and their combination for the treatment of chronic depression. NEJM 2000;342(20):1462–1470.
5. Klein D.N., Shankman S.A., Rose S. Ten-year prospective follow-up study of the naturalistic course of dysthymic disorder and double depression. Am J Psychiatry 2006;163(5):872–880.
6. McCullough J.P. Treatment for Chronic Depression: Cognitive Behavioral Analysis System of Psychotherapy. Guilford Press; 2000.