Persistent depressive disorder
Persistent depressive disorder (formerly dysthymia) is chronic, low-grade depressed mood present more days than not for at least 2 years with at least two associated symptoms and no symptom-free interval longer than 2 months. First-line treatment is long-term individual insight-oriented psychotherapy or cognitive behavioral therapy (CBT); a selective serotonin reuptake inhibitor (SSRI) such as sertraline is added when psychotherapy alone fails.
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What this article covers
- Overview
Chronic, low-amplitude depression: persistent depressive disorder (PDD), previously classified as dysthymia, is a depressed mood present more days than not for at least 2 years (at least 1 year in…
- Epidemiology
Shared burden with depressive disorders broadly: depressive disorders as a group, of which PDD is one member, carry a lifetime prevalence of approximately 20% in developed countries; women are affected almost twice as often as men.
- Risk factors
Family history of mood disorders: favors adding pharmacotherapy early rather than psychotherapy alone.
- Pathophysiology
Mood-disorder framework: PDD falls within the broader category of mood disorders, characterized by an abnormal depressed mood associated with psychomotor, cognitive, and vegetative symptoms that cause functional impairment.
- Clinical features
Core duration and symptom-count criteria: depressed mood present most of the time for at least 2 years (at least 1 year in children/adolescents) plus at least 2 of: appetite change, fatigue or low…
- Differential diagnosis
Major depressive disorder: five or more symptoms, including depressed mood or anhedonia, nearly every day for the same 2-week period, versus the 2-year, lower-symptom-count threshold of PDD; the two overlap in double depression.
- Diagnosis
Diagnosis is clinical: confirmed by history establishing depressed mood most of the time for at least 2 years (at least 1 year in children/adolescents), at least 2 associated symptoms, no…
- Management
First, stratify safety: assess suicidal ideation and risk factors at each visit; hospitalize only if actively suicidal or otherwise unsafe, since PDD alone does not require inpatient admission.
- Complications
Double depression: superimposed major depressive episodes on a chronic PDD baseline are common and are the most frequent acute complication requiring reassessment of the treatment plan.
- Prognosis
Chronic by definition: present for at least 2 years (at least 1 year in children/adolescents) and often traces back to childhood or adolescent onset, making spontaneous long-term remission uncommon without treatment.
- Prevention
Universal screening: screen all patients for depression using the two-question PHQ-2, with systems ensuring accurate diagnosis, effective treatment, and follow-up for anyone who screens positive.
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