Persistent depressive disorder is a form of depression in which low mood lasts for years rather than arriving in episodes. The depressed mood is present most of the day, more days than not, for at least two years, alongside at least two other symptoms such as poor appetite, sleep problems, low energy or hopelessness.
Key points
- Persistent depressive disorder is low mood on most days for at least two years, plus at least two other depressive symptoms.
- Dysthymia is the older name. DSM-5 merged dysthymia and chronic major depression; ICD-11 keeps dysthymic disorder separate.
- The mood is steady rather than dramatic, so many people keep working and go undiagnosed for years.
- Double depression is a major depressive episode on top of the chronic low mood, and often what brings someone to a GP.
- "High functioning depression" is a search term, not a diagnosis, and appears in neither ICD-11 nor DSM-5-TR.
Symptoms
- Low mood most of the day, more days than not; low self-esteem, self-criticism and indecision; a settled belief that this is how life is.
- Low energy or tiredness that rest does not fix; sleeping or eating too little or too much.
- Getting work done while taking little pleasure in any of it; pulling back from friends and family.
Causes and risk factors
- Depression is multifactorial: genetics, social and psychological factors, not a single chemical imbalance.
- Childhood adversity, maltreatment, or loss of a parent; higher rates of chronic depression among close relatives.
- An earlier age at first onset, more traumatic events across a lifetime, high anxiety and neuroticism.
Treatment
- Initial treatment: consider CBT, an SSRI, an SNRI, a tricyclic antidepressant, or CBT combined with an SSRI or tricyclic.
- If no response: further options needing specialist advice, plus vocational and social rehabilitation or befriending.
- Treatment usually takes longer than for a single episode, with progress measured over months.
When to speak to a professional
- Low mood has been present most days for two years or more.
- You cannot remember the last time you felt well.
- The low mood has recently deepened, or new symptoms have appeared.
- You are using alcohol or drugs to cope.
If you need help now: Samaritans, call 116 123, free, 24/7. Shout, text SHOUT to 85258. NHS 111, then choose the mental health option. Call 999 if anyone is in immediate danger.