The Difference Between Depression and Persistent Depressive Disorder, aka Dysthymia
What’s it called when you feel sad or hopeless for weeks, months, or even years? If you’re thinking depression, yes, that’s true. But it could also be persistent depressive disorder (PDD), also known as dysthymia.
Persistent depressive disorder is a pretty new clinical diagnosis that describes long-term feelings of sadness and listlessness that don’t quite meet the diagnostic criteria for major depressive disorder.
When most of us think about and talk about depression, we’re referring to major depressive disorder (MDD), sometimes called clinical depression. And even though the criteria for diagnosing MDD is pretty flexible, it’s also possible to have depressive symptoms that don’t quite fit the clinical diagnosis. For some, that’s where a diagnosis of PDD comes in.
This condition made its clinical debut in the DSM-5, the most recent version of the manual mental health professionals use to make diagnoses, published in 2013. Before that, PDD was known as dysthymia and was mainly used to signify that someone was experiencing depressive symptoms for two years or more—but not enough of them, or not in a severe enough form, to diagnose them with major depressive disorder.
Now, anyone who experiences clinically significant depression for at least two years at a time, whether or not it’s severe enough to meet the criteria for major depression, can be diagnosed with persistent depressive disorder.
In order to differentiate persistent depressive disorder from major depressive disorder, let’s first go over what constitutes a diagnosis of major depressive disorder.
In order to be diagnosed with MDD, you must exhibit at least five symptoms from a specific list, and at least one of those symptoms must be either depressed mood or loss of interest or pleasure in things you normally enjoy. Here are some of the other possible symptoms, which you’d need to be experiencing within the same two-week span:
Significant weight loss or gain, or a decrease or increase in appetite
Insomnia or hypersomnia (excessive sleepiness)
Moving either more slowly or more restlessly than usual
Fatigue or loss of energy
Feelings of worthlessness or immense guilt
A harder time thinking, concentrating, or making decisions
Recurrent thoughts of death, recurrent suicidal ideation (even without a specific plan), a suicide attempt, or a specific plan for dying by suicide.
Another crucial aspect of major depressive disorder is that these symptoms cause significant distress and inhibit your ability to function in some way (at work, in social settings, or just in your day-to-day life).
People most often experience major depressive episodes for at least a few months at a time, Katherine L. Wisner, M.D., professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine, tells SELF, though these episodes can sometimes be as short as two weeks.
Persistent depressive disorder, on the other hand, can be harder to pinpoint.
In order to have persistent depressive disorder, you need to experience a depressed mood for most of the day for the majority of days over a period of at least two years, along with a few other specific symptoms.
Of course, even the phrase “depressed mood” is open to interpretation, but for these purposes it can be something you realize on your own or something that your family or friends have picked up on and mentioned to you.
Beyond that, you must also exhibit two or more of the following symptoms:
Poor appetite or overeating
Insomnia or hypersomnia
Low energy or fatigue
Low self-esteem
Difficulty concentrating or making decisions
Feelings of hopelessness
Unlike with MDD, the symptoms of PDD don’t necessarily have to cause significant distress or impairment—but they might.
Since we’re talking about symptoms of depression that last a long time—but aren’t quite debilitating—it can be especially hard for patients and doctors to identify it.
“It has been described as [having] a depressive personality,” Pierre Azzam, M.D., assistant professor of psychiatry at the University of Pittsburgh Medical Center, tells SELF. “People are so accustomed to experiencing pessimism or low mood or feeling gloomy that it almost starts to feel like it's who they are.”
Just because persistent depressive disorder and major depressive disorder are separate conditions doesn’t mean they’re mutually exclusive.
In fact, people can experience both at the same time, a condition sometimes called “double depression,” Dr. Azzam says. You might have persistent depressive disorder for years, then on top of it, endure a major depressive episode.
If you’re starting to think you have persistent depressive disorder, seek treatment as soon as possible, Dr. Wisner says. In addition to getting screened for PDD and/or MDD, it’s also important to get a good medical workup. Symptoms of depression, like severe fatigue, can overlap with conditions like hypothyroidism and anemia. “It is important to treat any underlying illness to get the best response to treatment for PDD,” Dr. Wisner says.
It’s also essential to rule out bipolar disorder, she says. This mental illness can cause feelings of depression coupled with episodes of mania (basically swinging from periods of being down and being elated or really energetic), according to the National Institute of Mental Health.
The distinction between these conditions is important because your doctor may handle bipolar depression much differently than other health issues that cause similar feelings; some medications doctors might prescribe to treat depression have been associated with mania, though more investigation needs to be done. No matter what you’re dealing with, it’s important that your doctor is sure of your diagnosis before beginning treatment.
Treatment for persistent and major depressive disorder is similar, but some experts view PDD as being harder to tame.
Although it depends on the person, treatment for either of these conditions usually involves a combination of medication and psychotherapy.
If you see a doctor who confirms you have PDD or MDD, they might recommend antidepressants, usually selective serotonin reuptake inhibitors (SSRIs). SSRIs block the reabsorption of the neurotransmitter serotonin in your brain, making more serotonin available and potentially lifting your mood. They also tend to cause fewer side effects than other antidepressants, so they’re the most common kind prescribed.
Other forms of antidepressants include serotonin norepinephrine reuptake inhibitors (SNRIs), which block the reabsorption of serotonin and the neurotransmitter norepinephrine in your brain, and atypical antidepressants, which don’t fit neatly into other antidepressant categories and each work in their own ways. Unfortunately, finding the right medication and proper dosage may take some trial-and-error, since each person responds to medicine differently. Here’s more information that can help you find the best antidepressant for you.
When it comes to therapy, several different types can help people with PDD or MDD. For example, cognitive behavioral therapy focuses on changing negative thoughts and behaviors. There’s also interpersonal therapy, which centers around resolving personal relationships and social functioning. Dr. Wisner says another good form of therapy is behavioral activation, in which a therapist helps you to understand which activities you might be neglecting that you can re-incorporate into your life or do more often to positively affect your mood.
Although treatment is often similar for both PDD and MDD, some people find PDD takes longer to respond to treatment, Dr. Azzam says, sometimes up to a few months before any noticeable improvement takes place. Doctors aren’t entirely sure why. “It may be perhaps that the duration of persistent depressive disorder produces neurological changes,” Dr. Azzam explains.
Still, that doesn’t mean you should just try to push through persistent depressive disorder if you think you have it. If you experience any symptoms of depression—even if you don’t think they’re “bad enough”—check in with a health care provider to talk about them. The earlier you receive treatment, the better.
Related:
