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Health Guide / Depression

Persistent depressive disorder: long term depression

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Reviewed by Felix Gussone, MD, written by Robert Roy Britt

Last updated: Apr 26, 2021
5 min read

table of contents

  1. Major depressive disorder vs. persistent depressive disorder 
  2. Symptoms of depression
  3. What causes depression
  4. Seeking diagnosis and treatments

Disclaimer

If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

We all feel depressed now and then. But clinical depression, which can be diagnosed by a psychiatrist and can often benefit from treatment, goes beyond brief flashes of sadness. It’s chronic and can be debilitating, getting in the way of work, relationships, and the enjoyment of life. 

There are several different terms used to define and discuss varying types of depression. One distinction psychiatrists will make in a diagnosis involves the duration of symptoms: persistent depressive disorder and major depressive disorder.

If you’re really feeling down, and the feeling won’t go away, and you also feel unable to deal with it, you may have one of these types of clinical depression.

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Major depressive disorder vs. persistent depressive disorder 

There is no single type of depression nor one simple definition or cause (Institute of Medicine (US) Committee on Depression, 2009). Depression can be bipolar (meaning it is matched with a manic phase) or unipolar. 

It can be seasonal or long-lasting, and the underlying causes or triggers can vary greatly. Depending on how it’s defined, depression affects about 10% of US adults in a given year and some 21% during their lives (Hasin, 2018).

Psychiatrists define major depressive disorder as “a serious medical illness that negatively affects how you feel, the way you think and how you act” (American Psychiatric Association, 2013). 

Major depressive disorder, also sometimes called “unipolar major depression,” involves one or more episodes of serious, clinically diagnosed depression, including five or more of the symptoms noted below for at least two straight weeks (Lyness, 2021).

Persistent depressive disorder is similar, but rather than being episodic, it lasts for two years or more. People with persistent depressive disorder (also called dysthymia) often say they’ve been depressed for a long time (Patel, 2020). 

Symptoms of depression

The core symptoms for persistent or major depression are the same, and a diagnosis can be made when a person’s usual level of functioning is hampered by at least some of the following symptoms (American Psychiatric Association, DSM-5, 2013):

  • Sadness or depressed mood most of the day
  • Loss of interest or pleasure in usual activities
  • Weight gain or loss
  • Poor sleep or oversleeping
  • Fatigue or loss of energy
  • Pacing, fidgeting, or other purposeless activity
  • Slowed movement or speech
  • Guilt or a sense of worthlessness
  • Difficulty thinking, concentrating, or making decisions
  • Recurring thoughts of death or suicide

Grief and sadness may come and go based on events or transient experiences and feelings, but clinical depression—whether episodic or constant—is marked by the inability to cope amid feelings of self-loathing or worthlessness.

What causes depression

Depression has many causes. Genetics is thought to be about 40 to 50% responsible for cases of depression (Lohoff, 2010), and heredity—the genes you inherit from your parents—seems to play a greater role in the most severe cases (Sullivan, 2000).

Environment and experience can certainly factor in, however. Traumatic events from childhood or adult life, poverty, alcohol use, even diseases, and other medical conditions can contribute to the disease (Institute of Medicine Committee on Depression, 2009).

Depression can set at any point in life, and it can come and go over time or become a fixture. While children go through many mood phases and naturally have mood swings that can look like depression, about 3% of them actually meet the definition of clinical depression (Ghandour, 2019).

Seeking diagnosis and treatments

If you feel depressed for more than two weeks—based on any of the symptoms above—there is, of course, no need to wait years to learn whether you might experience the episodic nature of major depressive disorder or if your condition might become persistent. It’s time to talk to a medical professional. 

And it’s wise to go in armed with the above information. Most people with depression visit a primary care healthcare provider rather than a psychiatrist. While a family doctor should be able to help with an initial evaluation, studies have shown that the diagnosis of depression is missed in at least 50 percent of depressed primary care patients (Mitchell, 2009). Oftentimes, a referral to a psychiatrist is necessary to properly diagnose and treat depression. 

The persistent depressive disorder isn’t very different from the management of a major depressive disorder and the general principles of pharmacotherapy and psychotherapy remain the same.

Antidepressants and talk therapy are among the most commonly prescribed treatments, regardless of the type of depression. This combination has been shown to be more effective than either treatment independently (Cuijpers, 2009).

When it comes to antidepressants, SSRIs (selective serotonin reuptake inhibitors) such as fluoxetine (brand name Prozac; see Important Safety Information) are often the first-line treatment (Patel, 2020).

People suffering from depression need to be informed of all the treatment options and possible outcomes, especially considering these facts. Therapies for depression have been scientifically proven to be effective for many people with depression.

However, some people—especially children and adolescents—can recover from depression on their own. This so-called spontaneous improvement is still understudied but has become a focus of recent research.

At the same time, many others don’t respond positively to the treatments (Cuijpers, 2020). Talk to your healthcare provider about what treatment option is right for you.

The label of depression can deter people from seeking a professional evaluation of their unending sadness or grief. But depression is common, and in today’s world, it’s certainly understandable.

If your lousy mood becomes persistent and you just don’t know how to deal with it, heed those signs and seek help.

References

  1. American Psychiatric Association. What Is Depression? Retrieved from https://www.psychiatry.org/patients-families/depression/what-is-depression
  2. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, American Psychiatric Association, Arlington, VA, 2013. Retrieved from: https://dsm.psychiatryonline.org/doi/book/10.1176/appi.books.9780890425596
  3. Cuijpers P, Dekker J, Hollon SD, Andersson G. Adding psychotherapy to pharmacotherapy in the treatment of depressive disorders in adults: a meta-analysis. J Clin Psychiatry. 2009 Sep;70(9):1219-29. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/19818243/
  4. Ghandour RM, Sherman LJ, Vladutiu CJ, Ali MM, Lynch SE, Bitsko RH, Blumberg SJ. Prevalence and treatment of depression, anxiety, and conduct problems in U.S. children. The Journal of Pediatrics, 2019;206:256-267. Retrieved from: https://www.jpeds.com/article/S0022-3476(18)31292-7/fulltext
  5. Hasin DS, Sarvet AL, Meyers JL, et al. Epidemiology of Adult DSM-5 Major Depressive Disorder and Its Specifiers in the United States. JAMA Psychiatry 2018; 75:336. Retrieved from https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2671413
  6. Lyness, Jeffrey. Unipolar depression in adults: Assessment and diagnosis. Retrieved 04/2021 from https://www.uptodate.com/contents/unipolar-depression-in-adults-assessment-and-diagnosis
  7. Lohoff F. W. (2010). Overview of the genetics of major depressive disorder. Current psychiatry reports, 12(6), 539–546. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077049/
  8. Mitchell AJ, Vaze A, Rao S. Clinical diagnosis of depression in primary care: a meta-analysis. Lancet. 2009 Aug 22;374(9690):609-19. doi: 10.1016/S0140-6736(09)60879-5. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/19640579/
  9. National Research Council (US) and Institute of Medicine (US) Committee on Depression, Parenting Practices, and the Healthy Development of Children; England MJ, Sim LJ, editors. Depression in Parents, Parenting, and Children: Opportunities to Improve Identification, Treatment, and Prevention. Washington (DC): National Academies Press (US); 2009. 3, The Etiology of Depression. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK215119/
  10. Patel RK, Rose GM. Persistent Depressive Disorder. [Updated 2020 Oct 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK541052/
  11. Pim Cuijpers, Argyris Stringaris, Miranda Wolpert (2020), Treatment outcomes for depression: challenges and opportunities. The Lancet Psychiatry, Feb. 17 https://doi.org/10.1016/S2215-0366(20)30036-5. Retrieved from https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(20)30036-5/fulltext
  12. Sullivan PF, Neale MC, Kendler KS. Genetic epidemiology of major depression: review and meta-analysis. Am J Psychiatry (2000) 157:1552–62. doi: 10.1176/appi.ajp.157.10.1552. Retrieved from https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.157.10.1552
felix gussone
Felix Gussone, MD

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.

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Important Safety Information for Fluoxetine

Warning: Suicidal Thoughts and Behaviors

Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. In short-term studies, antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults under age 24. These studies did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in patients over age 24; there was a reduction in risk in patients 65 and older.

Patients of all ages being treated with antidepressants should be observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially early during antidepressant treatment and when the dose is adjusted up or down. Families and caregivers of patients should look for the emergence of symptoms on a day-to-day basis, since changes may be abrupt.

Call your healthcare provider right away or 911 in an an emergency if you observe any of the following behaviors, especially if they are new, worse, unusual, or worry you: emergence of suicidality, worsening of depression, emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, inability to sit still or restlessness, racing thoughts that you can’t fully control, or becoming easily distracted.

What is the FDA-approved use of fluoxetine?

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) used for acute and maintenance treatment of Major Depressive Disorder (MDD).

Who should not use fluoxetine?

Do not use fluoxetine if:

  • You are taking a class of medications called monoamine oxidase inhibitors (MAOIs). Examples of MAOIs include isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Emsam), and tranylcypromine (Parnate), linezolid, or intravenous methylene blue. MAOIs may increase the risk of serotonin syndrome.
  • You are taking a medication called pimozide or thioridazine. Taking these medications with fluoxetine can increase the risk of prolonged QT interval, which is a potentially dangerous change to the electrical signals that make your heart beat.

How should I take fluoxetine?

You can take fluoxetine with or without food. 

You should take fluoxetine exactly as prescribed, and continue to take fluoxetine as prescribed even after your symptoms improve. You should not change your dosing regimen or stop taking fluoxetine without discussing with your provider first. A gradual reduction in dosage rather than abruptly stopping is recommended whenever possible.

If your symptoms are not improving or you have any questions about changing or stopping medication, reach out to your Ro-affiliated provider for guidance.

What should I tell my Ro-affiliated provider before using fluoxetine?

  • Fluoxetine has many drug interactions. It’s important to tell your Ro-affiliated provider all of the medications you are currently taking, including prescription, over-the-counter medications, vitamins, and herbal and dietary supplements. Some medications to watch out for include:
    • Monoamine oxidase inhibitors (MAOIs), including the antibiotic linezolid (Zyvox) and intravenous methylene blue (rare)
    • NSAIDs, such as ibuprofen or naproxen
    • Aspirin
    • Blood thinners, such as warfarin (Coumadin)
    • Migraine medications called triptans, such as sumatriptan (Imitrex)
    • Benzodiazepines, such as diazepam and alprazolam
    • Other or SSRIs or SNRIs, such as sertraline (Zoloft)
    • Tamoxifen
    • St. John’s Wort
  • It’s important to share your entire medical history with your provider. In particular, tell your provider if you have a past history of:
    • Suicidal thoughts or attempted suicide
    • Family history of Bipolar Disorder or family history of suicide
    • Seizures
    • Irregular heartbeat or heart issues
    • Bipolar Disorder
    • Glaucoma or eye problems
    • Diabetes
  • Tell your provider if you are pregnant, planning to become pregnant, or breastfeeding. SSRI use, particularly later in pregnancy, may increase risk of complications in the newborn. You should discuss with your provider if fluoxetine should be used during pregnancy. There have been reports of fluoxetine passing into breast milk. Talk to your provider about the best way to feed your baby while taking fluoxetine.

Withholding or providing inaccurate information about your health and medical history in order to obtain treatment may result in harm, including, in some cases, death.

What are the most serious side effects that I or a caregiver should monitor for when taking fluoxetine?

If you are experiencing a medical emergency, call 911 or seek immediate medical attention.

These serious side effects are rare, but can occur with fluoxetine. You or a caregiver should carefully monitor for these side effects, especially in the beginning of treatment and with dose changes.

  • Serotonin Syndrome: Serotonin syndrome is an uncommon, potentially life-threatening condition that occurs when taking too much of an SSRI or SNRI at once or when fluoxetine is taken along with other drugs that increase the activity of serotonin in the central nervous system. These medications may include MAOIs, triptans (a class of drugs used to treat migraines), tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. John’s Wort. Monitor for symptoms of elevated body temperature, flushing, sweating, abdominal pain, diarrhea, agitation, and a racing heartbeat.
  • Allergic Reactions and Rash: Tell your provider if you develop a rash or hives. Discontinue use of fluoxetine and seek emergency care immediately if you have a severe allergic reaction. Signs and symptoms of a severe allergic reaction include swelling of the face, eyes, or mouth, or having trouble breathing. 
  • Activation of Mania/Hypomania: Especially at the beginning of treatment, monitor for changes in behavior such as an unusually elevated mood, feeling unusually irritable, a big increase in energy, being more talkative than usual, racing thoughts, or engaging in risky behaviors. These changes in behavior could be signs of undiagnosed Bipolar Disorder.
  • Abnormal Bleeding: Tell your provider if you experience any increased or unusual bruising, bleeding, or nose bleed. Fluoxetine may increase the risk of bleeding when taken with NSAIDs (such as ibuprofen or naproxen), aspirin, or blood thinners such as warfarin (Coumadin).
  • QT Prolongation: Tell your provider right away if you experience fast, slow, or irregular heart rate, shortness of breath, fainting, or dizziness, which may indicate serious cardiac arrhythmia.
  • Cognitive and Motor Impairment: Fluoxetine may impair judgment, thinking, and motor skills. Avoid driving a car or operating hazardous machinery until you know that your performance is not affected. Do not drink alcohol while you take fluoxetine.
  • Eye Effects: In rare instances, antidepressants may cause a certain type of eye problem called acute angle-closure glaucoma. Monitor for eye pain, changes in your vision, or swelling or redness in or around the eye.
  • Low Sodium in the Blood (Hyponatremia): Elderly people may be at greater risk for this condition. Symptoms may include headache, weakness or feeling unsteady, confusion, problems concentrating or thinking, and memory problems.

What are the most common side effects of fluoxetine?

  • Nausea, diarrhea
  • Lack of appetite, weight loss
  • Dry mouth
  • Headache
  • Sexual problems, including decreased sex drive, erectile dysfunction, or trouble ejaculating
  • Change in sleep habits, including insomnia or increased sleepiness
  • Nervousness, anxiety
  • Lack of energy, or feeling generally weak
  • Tremor
  • Sweating

You are encouraged to report negative side effects of prescription products to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

This information is not comprehensive. Please see the full Prescribing Information for complete safety information.