Persistent Depressive Disorder (PDD)
Overview
Persistent Depressive Disorder (PDD) is characterized by chronic, long-lasting depression that is not as severe as major depressive disorder (MDD). Formerly referred to as dysthymia or dysthymic disorder, a diagnosis of PDD requires having experienced a combination of depressive symptoms for two years or longer.[1] More than half of those with PDD will eventually have an episode of major depression.[2,3]
Harvard Medical School notes that PDD is a serious disorder and should not be considered “minor” depression. It is also not an intermediate condition between severe clinical depression and experiencing general sadness or a bad day. In some cases, PDD is more disabling than major depression, especially given the long duration of the disorder.[4]
PDD often begins fairly early in one’s life (i.e., during childhood, teen years or young adulthood) and tends to continue long-term if left untreated.[5] Nearly as common as major depression, roughly 6% of the U.S. population has had PDD at some point. One of the most commonly-seen disorders in those attending psychotherapy, with roughly one-third of clients have reached out for therapy for this debilitating disorder.[6]
Causes
While the exact cause of PDD is not yet known, the Mayo Clinic and Johns Hopkins Medicine note there may be more than one contributing factor. These include:[7,8]
Biological Differences - PDD affects women twice as often as men.
Brain Chemistry - Changes in naturally occurring brain chemicals (i.e., neurotransmitters) may play a large role in the development and treatment of depression.
Inherited Traits - PDD appears to be more common in those whose blood relatives also have the condition, although the exact genes linking to it are currently unknown.
Life Events - Similar to major depression, traumatic and other highly stressful events can trigger PDD in some people.
In addition, certain risk factors appear to make someone more susceptible to developing PDD. Such risk factors may include: a history of other mental health disorders (e.g., a personality disorder) and negative personality traits (e.g., negativity, low self-esteem, high interpersonal dependence, self-criticism and chronically thinking “the worst will happen”.)[9]
Signs & Symptoms
Symptoms of PDD usually appear and fade over a period of years. While the intensity of symptoms can change over time from mild, moderate to severe, they usually don't disappear for more than two months at any given time. It is also important to note that episodes of MDD may occur before or during PDD.[10]
Those experiencing PDD may feel sad and empty, lose interest in daily activities and have difficulty getting things done. They may also experience low self-esteem, feel like a failure and feel hopeless. These depressive feelings can last for years, often interfering with relationships, school/work and life’s daily activities. Others may describe someone with PDD as acting gloomy, constantly complaining or unable to have fun – often in situations where others are upbeat, joyful and having an overall good time.[11]
Symptoms of PDD can cause major disruptions in one’s life and may include:[12]
Sadness or emptiness
Loss of interest in daily activities
Tiredness and lack of energy despite adequate sleep
Low self-esteem, self-criticism or feeling incapable of work and other activities
Trouble focusing clearly and/or making decisions
Problems getting things done well and on time
Quickly becoming annoyed, impatient, or angry
Avoidance of social activities
Unfounded or excessive feelings of guilt and worries over the past
Poor appetite or overeating
Hopelessness
In children, symptoms of persistent depressive disorder may include depressed mood and irritability (i.e., easily annoyed, impatient, or angry).
Complications
The Mayo Clinic notes the following conditions may be comorbid/coexisting with PDD:[13]
Lower quality of life
Major depression, anxiety disorders, and other mood disorders
Relationship difficulties and family conflicts
School or work problems and trouble getting things done
Ongoing pain and/or general medical illnesses
Personality disorders or other mental health disorders
Diagnosis
Johns Hopkins Medicine explains that to diagnose this condition, an adult must have a depressed mood for at least 2 years (or one year in children and adolescents), and experience at least 2 of the afore-mentioned symptoms. The symptoms of this illness may look like other mental health conditions, thus proper diagnosis by a trained medical professional or licensed mental health provider is key.[14]
Typically, a health care provider will take a history of the patient’s mood and other mental health symptoms.[15] Several brief screening questionnaires can be used to test for PDD, including the Hamilton Rating Scale for Depression and the Patient Health Questionnaire. If a patient’s answers suggest the presence of PDD, a standard clinical interview can be used to confirm the diagnosis.[16] In addition, blood and urine tests are also often used to rule out potential medical causes of depression.[17]
Unfortunately, those with PDD often grow accustomed to their mild depressive symptoms or simply think this is “who they are” and therefore do not seek help. However, early diagnosis and treatment are key to recovery and a fuller, happier life.[18]
Treatment
Since PDD can significantly impact one’s daily life as well as increase the risk of suicide, timely and proper treatment is essential.[19] Because this condition usually lasts for longer than 5 years, long-term treatment may be needed.[20]
As Harvard Medical School explains, unfortunately most people with PDD are untreated. This may be due to their general acceptance of the disorder as a normal part of their life of who they are. Conversely, those who do express concern to their family doctors may only note their physical symptoms, causing their disorder to often be undiagnosed. In older persons, PDD may be mistaken as signs of dementia, apathy, or irritability.[21]
Similar to major depression, PDD is often treated with a psychotherapy and medication. Therapy can provide advice, reassurance, sympathy, and education about the disorder. Specifically, cognitive therapy identifies and corrects thought patterns that promote self-defeating attitudes, which are especially prevalent in PDD. Behavioral treatment (such as those learned in cognitive behavioral therapy) can improve social skills and teach ways to manage stress and unlearn learned helplessness. Psychodynamic therapy can help patients resolve emotional conflicts, especially those derived from adverse childhood experiences. Additionally, interpersonal therapy can help patients cope with personal disputes, loss and separation, and transitions between social roles.[22]
Medications often prescribed by a psychiatrist or other physician to treat PDD often include: selective serotonin reuptake inhibitors (SSRIs) like fluoxetine (Prozac) and sertraline (Zoloft), one of the dual action antidepressants such as venlafaxine (Effexor), or a tricyclic antidepressant like imipramine (Tofranil).[23] It is important to note that while medicine is often effective for PDD, they sometimes do not work as well as they do for major depression and may take longer to work.[24] Since it may take 4 to 6 weeks for anti-depressants to have a full effect, patients should continue to take the prescribed medicine, even if it doesn’t seem to be initially working.[25] A patient should never stop taking a medicine on their own, even if they feel better or have side effects – if there are any concerns or questions, their prescribing doctor should be contacted so they can instruct the patient about their medication (i.e., if it should be slowly tapered, discontinued, or switched to another type of medication).[26]
In addition to therapy and medication, Mount Sinai Health System notes that there are a multitude of things a person can try to improve PDD, such as:[27]
Get enough sleep.
Follow a healthy, nutritious diet.
Take medicines correctly and discuss any side effects with your provider.
Learn to watch for early signs that your PDD is getting worse; have a plan for how to respond if it does.
Try to exercise regularly.
Look for activities that make you happy.
Talk to someone you trust about how you are feeling.
Surround yourself with people who are caring and positive.
Avoid alcohol and illegal drugs. These can make your mood worse over time and impair your judgment.
Understand the biological and/or environmental factors that may be behind depressive thoughts and feelings.
Joining a support group for people who are having similar issues (such as depression or PDD) can also help. A therapist or health care provider may be able to recommend a group.
Johns Hopkins Medicine notes that while depression can bring on negative thoughts and feelings that can make someone feel like giving up - but it is important to realize that these negative views are part of the depression and may not reflect reality. In addition to the afore-mentioned steps one can take, JHM recommends the following actions to help combat depressive thoughts and feelings:[28]
Get help. If you think you may be depressed, see a professional as soon as possible.
Set realistic goals and don’t take on too much.
Break large tasks into small ones. Set priorities, and do what you can as you can.
Do things that make you feel better. Going to a movie, gardening, or taking part in religious, social, or other activities may help. Doing something nice for someone else can also help.
Expect your mood to get better slowly, not right away. Feeling better takes time.
It is best to postpone big decisions until the depression has lifted. Before making a big change (e.g., switching jobs, getting married or divorced) discuss it with others who know you well and have a more objective view of your situation.
Remember: People rarely "snap out of" a depression. But they can feel a little better day-by-day.
Try to be patient and focus on the positives. This may help replace the negative thinking that is part of the depression, and the negative thoughts will disappear as your depression responds to treatment.
Let your family and friends help you.
Prevention
While there is no absolute way to prevent PDD, it is important to identify and treat this disorder as early as possible. Because PDD often starts in childhood or during one’s teenage years, identifying children at risk of this condition may help them get early treatment.[29]
Although these suggestions cannot prevent PDD, the Mayo Clinic adds that the following strategies may help reduce or prevent symptoms from occurring:[30]
Take steps to control stress - to increase your ability to recover from problems (i.e., resilience) and to boost your self-esteem.
Reach out to family and friends - especially in times of crisis, to help you get through rough spells.
Get treatment at the earliest sign of a problem - by reaching out to a licensed mental health professional or medical doctor to help prevent symptoms from worsening.
Consider getting long-term treatment - to help prevent a relapse of symptoms of PDD.
If you or someone you know is suffering from symptoms of PDD or major depression, please reach out to a licensed mental health professional (e.g., a psychotherapist, psychologist, or psychiatrist) or primary care physician for guidance and support.
Contributed by: Jennifer (Ghahari) Smith, Ph.D.
references
1 NIH: National Institute of Mental Health. (n.d.) Persistent Depressive Disorder (Dysthymic Disorder). (accessed 12-8-2023) https://www.nimh.nih.gov/health/statistics/persistent-depressive-disorder-dysthymic-disorder#:~:text=Disorder%20(Dysthymic%20Disorder)-,Definition,lasting%20than%2C%20major%20depressive%20disorder
2 Johns Hopkins Medicine. (n.d.) Dysthymia. (accessed 12-8-2023) https://www.hopkinsmedicine.org/health/conditions-and-diseases/dysthymia
3 Harvard Health Publishing: Harvard Medical School. (March 9, 2014) Dysthymia. (accessed 12-8-2023) https://www.health.harvard.edu/newsletter_article/dysthymia
4 Ibid.
5 Mayo Clinic. (Dec 12, 2022) Persistent Depressive Disorder. (accessed 12-9-2023) https://www.mayoclinic.org/diseases-conditions/persistent-depressive-disorder/diagnosis-treatment/drc-20350935
6 Harvard Health Publishing: Harvard Medical School
7 Mayo Clinic
8 Johns Hopkins Medicine
9 Mayo Clinic
10 Ibid.
11 Ibid.
12 Ibid.
13 Ibid.
14 Johns Hopkins Medicine
15 Mount Sinai. (n.d.) Persistent Depressive Disorder. (accessed 12-9-2023) https://www.mountsinai.org/health-library/diseases-conditions/persistent-depressive-disorder
16 Harvard Health Publishing: Harvard Medical School
17 Mount Sinai
18 Johns Hopkins Medicine
19 Mount Sinai
20 Johns Hopkins Medicine
21 Harvard Health Publishing: Harvard Medical School
22 Ibid.
23 Ibid.
24 Mount Sinai
25 Johns Hopkins Medicine
26 Mount Sinai
27 Ibid.
28 Johns Hopkins Medicine
29 Mayo Clinic
30 Ibid.