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Questions and Answers

What is dysthymia or persistent depressive disorder?


Author: Canadian Mental Health Association, BC Division



Dysthymia, now called persistent depressive disorder or PDD, is a mood disorder. It is related depression (major depressive disorder). The difference between the two is in the number of symptoms and the amount of time that they last. Someone diagnosed with PDD would experience two to four of the symptoms below for at least two years with no periods of wellness during that time, while someone diagnosed with major depressive disorder would experience five or more of the symptoms below for at least two weeks.

Symptoms of PDD include:

  • Low mood, hopelessness, or emptiness
  • Low self-esteem
  • Irritability
  • Worry or guilt
  • Loss of interest in things you usually enjoy
  • Difficulties concentrating or making decisions
  • Changes in sleep (too much sleep or not enough sleep)
  • Changes in eating habits (eating too much or eating too little)
  • Fatigue
  • Withdrawal from others
  • Thoughts of suicide

There is a myth that PDD is not as severe an illness as major depressive disorder, but research shows that the disability of the illness, like the ability to work productively and enjoy hobbies, may be as severe in PDD as it is in major depressive disorder. As PDD involves a smaller number of symptoms that last for a very long time, many people begin to assume PDD is just part of their personality rather than an illness that can be effectively treated. So you should most certainly talk to a doctor or mental health professional if you think you might have PDD.

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About the author

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The Canadian Mental Health Association promotes the mental health of all and supports the resilience and recovery of people experiencing a mental illness through public education, community-based research, advocacy, and direct services. Visit



Q&A is for readers who want to take charge of their well-being, support a friend or loved one, find good help, or just learn more about mental health and substance use. Here, the information and resource experts at HeretoHelp will answer the questions that we’re asked most often. We'll offer tips and information, and we'll connect you with help in BC, Canada. If you have a question you’d like to ask, email us at [email protected], tweet @heretohelpbc, or log in to HeretoHelp and post a comment on this page.


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