Persistent depressive disorder (PDD), sometimes called dysthymia, is a long-running, lower-grade form of depression. People with this diagnosis often describe themselves as having always been a little down. That description is part of the clinical picture.
Quick view
- PDD requires depressed mood most of the day, more days than not, for at least two years in adults (one year in children and adolescents).
- Lifetime prevalence in U.S. adults is roughly 1.5 percent, with 12-month prevalence around 0.5 percent (Hasin et al., JAMA Psychiatry, 2018).
- Many patients meet criteria for both PDD and a major depressive episode, sometimes called double depression.
- It responds to the same general treatments as major depressive disorder, but recovery typically takes longer.
DSM-5-TR diagnostic criteria
According to the DSM-5-TR, PDD requires depressed mood for most of the day, for more days than not, for at least two years in adults, along with two or more of: poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, and feelings of hopelessness. The person must not have been free of these symptoms for more than two months at a time, and the symptoms must cause clinically significant distress or impairment.
Importantly, the criteria require that there has never been a manic or hypomanic episode and that the symptoms are not better explained by a psychotic disorder, substance use, or another medical condition. If a manic or hypomanic episode has ever occurred, the diagnosis shifts to a bipolar spectrum disorder and the treatment plan changes.
Epidemiology
The lifetime prevalence of PDD in U.S. adults is approximately 1.5 percent, with a 12-month prevalence of about 0.5 percent (Hasin et al., JAMA Psychiatry, 2018). PDD is more common in women than men by roughly 2 to 1, and the median age of onset is in the early twenties, with a substantial share of cases beginning in childhood or adolescence (Kessler et al., NCS-R, Arch Gen Psychiatry, 2005). Co-occurring anxiety disorders, substance use, and personality disorders are common.
What it can look like
A person who has felt low energy and low motivation for as long as they can remember. A person who assumes everyone feels this tired. A person who has built a life around managing a constant baseline of effort. Some patients describe the diagnosis as a relief, because it names a pattern they had attributed to personality.
How it shows up in different people
- In adults, the most common pattern is a stable, low-grade depression that has been present so long it feels like a personality trait.
- In adolescents, the criterion is one year rather than two, and the presentation often includes irritability rather than sadness.
- In older adults, PDD can be confused with the cognitive and energy changes of medical illness; a careful history is needed.
- In men, PDD is often unreported and may surface only after a partner or primary care visit raises it.
- In women, the rate is roughly twice that in men, with hormonal transitions sometimes amplifying symptoms.
How clinicians sort it out
The key features are duration and pattern. A careful history asks how the person felt in their teens, their twenties, and the years since. The clinician also screens for any past period of unusually elevated mood, since a single past hypomanic episode changes the diagnosis. Lab work (TSH, CBC, B12, vitamin D) and a medication review rule out medical contributors.
Screening
The PHQ-9 captures the symptoms but does not capture the duration that defines PDD; a clinician asks about the time course directly. The Mood Disorder Questionnaire (MDQ) is used to screen for bipolar history when PDD is being considered, since the differential matters for treatment.
When to seek same-day care
New or worsening suicidal thoughts, inability to keep yourself safe, severe withdrawal from food or fluids, or new psychotic symptoms are reasons for same-day care. Call 988, call 911, or go to the nearest emergency department.
Treatment
PDD responds to the same general treatments as major depressive disorder, including antidepressants and structured psychotherapies (cognitive behavioral therapy, the cognitive behavioral analysis system of psychotherapy, and interpersonal therapy all have evidence). Because the pattern is long-standing, treatment often takes longer to show its full effect, and most patients benefit from continuing both therapy and medication well after they feel improved. Combination treatment (medication plus psychotherapy) outperforms either alone in chronic depression (Keller et al., N Engl J Med, 2000).
Sources
- American Psychiatric Association. DSM-5-TR. 2022.
- Hasin DS, et al. Epidemiology of adult DSM-5 major depressive disorder and its specifiers in the United States. JAMA Psychiatry. 2018.
- Kessler RC, et al. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2005.
- Keller MB, et al. A comparison of nefazodone, the cognitive behavioral-analysis system of psychotherapy, and their combination for the treatment of chronic depression. N Engl J Med. 2000.
- National Institute of Mental Health. Depression overview. Accessed 2026.
Related
Major depressive disorder. Treatment. Relapse (glossary).
