Dysthymia: A guide to persistent depressive disorder (PDD)

What if you were depressed for so long that you forgot what happiness felt like? What if your low mood started to feel permanent, like part of your personality? This is the reality for many people with dysthymia, or persistent depressive disorder (PDD), a chronic depressive state that lasts two years or more. 

Dysthymia is a mental health condition that’s been described as “smoldering.” Its intensity can vary from month to month. Over the years, depressive episodes might be low-grade, mild to the point that they can be dismissed. Or someone with PDD might cycle through all the symptoms of major depressive disorder (MDD). Dysthymia has also been described as “high-functioning depression,” but its acute depressive episodes can sometimes be debilitating. Like all affective disorders, PDD hits people where it really hurts: in their happiness.

Clinicians recommend that everyone with symptoms of depression should be screened for dysthymia. Let’s take a look at how PDD differs from other mood disorders, and what can be done to address its chronic symptoms. 

What Is Dysthymia? 

What the American Psychiatric Association (APA) now calls persistent depressive disorder is actually a fusion of two earlier disorders: chronic major depressive disorder and dysthymic disorder. Those two disorders were combined in the latest version of the Diagnostic and Statistical Manual of Disorders, or DSM-5.

Persistent depressive disorder might have fewer symptoms than major depressive disorder, but it’s also more insidious, lasting at least two years. That’s a long time to feel down. People with PDD might see the sunshine every once in a while. They can emerge from their depression for up to two months at a time during the course of their disorder and still meet the criteria for dysthymia. But for at least two years they are depressed for most of the day, more days than not. 

A clinician can specify persistent depressive disorder in multiple ways. For example, PDD can be defined as one of the following four subtypes:  

1. PDD with pure dysthymic syndrome: In the last two years, the individual has never met the full criteria for a major depressive episode. 
2. PDD with persistent major depressive episode: In the last two years, the individual has often met the full criteria for a major depressive episode. 
3. PDD with intermittent major depressive episodes, with current episode: In the last two years, there have been periods of at least two months that didn’t meet the full criteria for a major depressive episode. But the individual is currently experiencing a major depressive episode. 
4. PDD with intermittent major depressive episodes, without current episode: Same as above, but the individual is not currently experiencing a major depressive episode.

Persistent depressive disorder can also be defined by severity (mild, moderate, severe), onset (early*, late, or peripartum), remission status (full or partial), and features (e.g., “with anxious distress” or “with atypical features”).

*Early onset is defined as before age 21. An early onset of PDD is associated with personality disorders.

Is Dysthymia a Serious Mental Illness?

Dysthymia, aka persistent depressive disorder, causes chronic mood changes that affect quality of life, so yes, it is a serious mental health condition. Dysthymia blunts the pleasure of day-to-day experience. It harms personal and occupational functioning. And it’s draining on the mind, body, and soul. Even if a depressive episode never reaches acute stages, it can be difficult to navigate the experience of being down in the dumps for weeks or months on end. Dysthymia is also associated with anxiety disorders and substance use disorders.

Dysthymia vs. Depression (PDD vs. MDD)

What is the difference between depression and dysthymia? “Depression” usually refers to major depressive disorder (MDD), a mental health condition that has a pretty clear onset and four more symptoms than persistent depressive disorder (PDD). Major depressive episodes need only last for two weeks, while dysthymia needs to last for two years or more. PDD is also characterized by waxing and waning symptoms. During the course of the disorder, a person might experience short periods of normal mood. And dysthymia/PDD tends to sneak up on an individual (have an “insidious onset”) so it’s not as easy to say exactly when the depression symptoms began. 

But to complicate matters, major depressive disorder can precede PDD. Someone can also have major depressive episodes during the course of their PDD. Lastly, if someone’s symptoms meet the criteria for MDD for two years, then they can be diagnosed with PDD and MDD. 

Dysthymia vs. Cyclothymia

Cyclothymic disorder is characterized by a pattern of mood swings that aren’t extreme enough to meet criteria for bipolar I, bipolar II, or major depressive disorder. The highs of cyclothymia are hypomanias that aren’t severe enough to qualify as manic or hypomanic episodes, and the lows of cyclothymia are depressions that aren’t severe enough to qualify as major depressive episodes. As in PDD, these mood disturbances are chronic, lasting at least two years in adults and one year in children and adolescents.  

Is Dysthymia the Same as Bipolar?

Dysthymia (now known as persistent depressive disorder, or PDD) is a depressive disorder, not a bipolar disorder. PDD may involve periods of normal mood, but not hypomanic or manic mood. 

What Are Dysthymia Symptoms? What Does Dysthymia Do to a Person?

Dysthymia has been called a “soft mood” disorder because its symptoms tend to be more modest than those of major depression. People with persistent depressive disorder may be able to mask their feelings better when they’re in social situations. But that doesn’t mean they’re not suffering. For at least two years they’ve been dealing with a persistent sad mood that’s been affecting their appetite, their sleep habits, their energy levels, their self-esteem, and/or their concentration. They might feel hopeless or indecisive. And they might have been feeling low for so long that they think sadness is an integral part of their personality. Imagine developing dysthymia as a teen at the same time your identity is forming. It would be easy to conflate yourself with your mood. This can all make it hard for mental health professionals to recognize the symptoms of dysthymia disorder. 

Diagnostic Criteria for Dysthymia DSM-5

To diagnose persistent depressive disorder, many American psychiatrists rely on criteria published in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (the DSM-5). Here are those criteria:

A. Adults experience a depressed mood for most of the day, the majority of days, for at least two years. In children and adolescents, this period is shortened to one year. Kids may also seem irritable rather than depressed. 

B. In addition to feeling depressed, someone experiences at least two of the following symptoms:

1. Diminished or increased appetite
2. Sleeping too much or too little
3. Fatigue or low energy levels
4. Low self-esteem
5. Cognitive impairments regarding focus and decision-making
6. Hopelessness

Note: All symptoms of major depression as well, but MDD can also include anhedonia (loss of interest or pleasure), psychomotor agitation or lethargy, and suicidal ideation. 

C. These symptoms never go away for longer than two months.

D. Criteria for a major depressive disorder may be continuously present for 2 years.

In addition, the symptoms can’t be better explained by another disorder, medication, substance abuse, or medical condition. They also must cause clinically significant distress or impairment. There’s no dysthymia test based on biomarkers, so mental health professionals use their best judgment.

What Triggers Dysthymia?

Persistent depressive disorder shares many risk factors with clinical depression:

• Temperamental (negative affectivity, other anxiety disorders)
• Environmental (history of trauma, early dysfunction with family members)
• Genetic and physiological (people with PDD will often have first-degree relatives with PDD)

You can read more about the contributors to different types of depression here. 

Dysthymia Treatments

Persistent depressive disorder can be effectively treated with the same approaches used to treat major depressive disorder. So what is the best treatment for dysthymia? There are two: psychotherapy and pharmacotherapy (prescription drug treatment). They are often combined for the best results.

Psychotherapy

Persistent depressive disorder is often treated with cognitive behavioral therapy (CBT), a type of talk therapy that works to change negative thought patterns. 

Dysthymia Medication

Doctors may prescribe antidepressants to someone with persistent depressive disorder. These include the following:

• Selective serotonin reuptake inhibitors (SSRIs)
• Tricyclic antidepressants (TCAs)
• Serotonin and norepinephrine reuptake inhibitors (SNRIs)

Because persistent depressive disorder is a chronic or lifelong condition, individuals may change their medication over their years. Sometimes a drug loses its efficacy, has negative side effects, or a new doctor recommends adjusting a prescription.