Persistent Depressive Disorder (PDD)
Reviewed by: HU Medical Review Board | Last reviewed: October 2023
Persistent depressive disorder (PDD), also called dysthymia, is a mild, chronic form of depression. Unlike the occasional sadness or low mood that everyone experiences at one point or another, PDD is a consistent, long-term condition that can have a big impact on a person’s daily life.1,2
PDD is different from major depressive disorder (MDD) in terms of how long it lasts and how intense it is. With MDD, people experience intense bouts of depression that may last weeks to months. These are followed by periods in which they feel better and symptoms improve.1-3
PDD, on the other hand, involves milder symptoms than MDD. But it is long-lasting, as symptoms can linger for years. This constant, low-grade depression can make it hard for those with PDD to remember a time when they felt "normal" or happy and can still greatly impact quality of life.1-3
Who gets PDD?
PDD can affect both adults and children. PDD often begins in childhood or the teenage years. Around 1.5 percent of American adults experience PDD each year. Women have nearly double the risk of developing PDD than men.2,3
What causes PDD?
Mental health experts do not understand the exact cause of PDD. Factors related to a person’s genes, environment, and nervous system may all play a role.4
Risk factors that may increase a person’s risk of PDD include:1,2,4
- Personal history – People with a history of other mental health disorders have an increased risk of PDD.
- Family history – Having a family member with PDD or another mental health disorder increases the risk.
- Brain chemistry – Imbalances in brain chemicals, such as serotonin and dopamine, are often linked with depression.
- Early trauma or stress – Experiencing trauma or stressful life events during childhood may increase a person’s risk of PDD.
- Social determinants of health – Socioeconomic status, access to healthcare, and social support, among others, can affect PDD. These factors can create barriers to treatment, worsen stressors, and add to the overall burden of the condition.
- Personality traits – PDD is more common in those who are naturally more negative or critical, and in those who have low self-esteem.
What are the symptoms of PDD?
The symptoms of PDD can vary from person to person. They may include:1,2,4
- Low energy or fatigue
- Persistent sadness or hopelessness
- Irritability (more commonly seen in children)
- Changes in appetite or weight
- Difficulty concentrating
- Sleep problems, either oversleeping (hypersomnia) or being unable to sleep (insomnia)
- Feelings of inadequacy or low self-esteem
- Lack of interest or pleasure in activities
- Social withdrawal
How is PDD diagnosed?
Diagnosing PDD can be tricky. Because it is subtle, it can be overlooked. To be diagnosed with PDD, a person must have symptoms for at least 2 years (or 1 year in children), with no more than 2 symptom-free months.1,3
Mental health experts use the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to make a diagnosis of PDD. Undergoing a physical exam and mental health evaluation are the first steps to getting a diagnosis. Other tests such as blood tests, urine tests, and thyroid tests may be needed to rule out other health issues.1,3
How is PDD treated?
The good news is that PDD is treatable, and people can find relief from their symptoms. Since this type of depression lasts for several years, long-term treatment is usually needed. A combination of the following is best when it comes to treating PDD:1,2,4,5
- Psychotherapy – Talk therapy, including cognitive behavioral therapy (CBT) or interpersonal therapy, can help with PDD. Therapy can help people understand and manage their thoughts and emotions.
- Medicine – Antidepressant drugs, such as selective serotonin reuptake inhibitors (SSRIs), can help manage PDD symptoms. These drugs help to balance brain chemicals that are responsible for mood.
- Lifestyle changes – Making healthy lifestyle changes can go a long way in managing a chronic condition like PDD. These changes can include regular exercise, a balanced diet, and a consistent sleep schedule. Avoiding alcohol and drugs is also recommended, as these substances can make depression worse.
- Support networks – Building a support system through friends, family, or support groups can be essential in managing PDD.
Other things to know
PDD is often more problematic than other forms of depression, simply because it can last for a longer time. It also can go undiagnosed because the symptoms might not be as severe or disruptive as those of MDD.5
People with PDD may have bouts of major depression that come and go. This means that it is possible to have PDD and MDD at the same time.1,4
While PDD can have a lasting impact on your life, various treatment options offer hope. If you or someone you know is struggling with persistent low mood and depressive symptoms, seek help from a mental health professional. Crisis support options like the 988 Suicide & Crisis Lifeline (calling or texting 988) are available 24 hours a day, 7 days a week.