Chronic depression or persistent depressive disorder (PDD) is a long-term type of depression. Adult symptoms typically persist for at least 2 years. Treatment for PDD usually involves a combination of psychotherapy and medication.

This article discusses PDD in more detail, including its symptoms, causes, treatments, and diagnosis. The article also answers some of the most common questions about chronic depression.

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PDD is the new Diagnostic and Statistical Manual of Mental Disorders, 5th edition text revision (DSM-5-TR) term for dysthymia or chronic depression. This type of depression lasts a minimum of 2 years but can usually last longer. It is the only depressive disorder where symptoms last this long.

Often, the onset of PDD occurs during childhood, adolescence, or early adulthood. It may be difficult for a person to detect PDD since its symptoms are less severe than major depressive disorder (MDD). Its persistent nature can also cause people to normalize symptoms.

Symptoms of PDD are similar to those of MDD, which include:

However, people with MDD usually alternate between periods of severe depression and periods with no symptoms. A depressive episode is a change from a person’s usual outlook and daily routine to a low mood and accompanying symptoms of depression.

Conversely, people with PDD usually have ongoing symptoms that persist for at least 2 years. Though these symptoms may be less severe than MDD symptoms, they can significantly affect a person’s mindset and overall well-being. They may cause a significant change in how a person views the world.

Learn more about the differences between MDD and PDD here.

Symptoms of PDD are similar to other types of depression, though they last longer and tend to be less severe.

In addition to a depressed mood for at least 2 years, symptoms of PDD include:

It is also possible for a person to experience symptoms of PDD and MDD simultaneously.

Researchers are still learning more about the causes of PDD, which may include neurotransmitters and receptors that influence mood. Medications usually target the neurotransmitter serotonin. However, researchers have found that additional neurotransmitters can also affect mood, including:

Researchers have also discovered areas of the brain showing a significant loss in volume in people with PDD. These include the frontal areas of the brain, principally the anterior cingulate and the orbitofrontal cortex, and the hippocampus.

Additional risk factors for PDD include:

To help treat and manage PDD, a person can make an appointment to speak with a mental health professional. Typically, PDD treatment strategies are similar to MDD treatments and involve a combination of medication and psychotherapy. In general, combining these two treatments is more effective than using one.

Individual treatment plans will vary depending on the causes of depression, the severity of symptoms, and how many symptoms are present.

Interpersonal therapy and cognitive behavioral therapy (CBT) are common psychotherapy types for PDD.

In the near future, doctors may recommend a new type of psychotherapy called the cognitive behavioral analysis system of psychotherapy (CBASP), which mental health practitioners developed specifically to manage chronic depression. However, research into the efficacy of CBASP is still ongoing.

Usually, the first-line antidepressant medications are selective serotonin reuptake inhibitors (SSRIs) due to their effectiveness and tolerability. Atypical antidepressants and serotonin-norepinephrine reuptake inhibitors (SNRIs) may also be effective.

Learn more about the differences between SSRIs and SNRIs here.

For a doctor to diagnose PDD in adults, a person must have a depressed mood for at least 2 years. Children and teenagers must have an irritable mood in place of a depressed mood for at least 1 year for a diagnosis. Additionally, the symptoms must not be absent for longer than 2 months.

Along with a depressed or irritable mood, a person must have at least two of the following symptoms:

  • decreased appetite or overeating
  • insomnia or oversleeping
  • lack of energy or fatigue
  • low self-esteem
  • difficulty concentrating and making decisions
  • hopelessness

A doctor may also rule out medical and organic causes. They may screen for additional DSM-5-TR diagnoses such as:

Below are some of the most common questions and answers about chronic depression.

What are the different types of depression?

The five types of depression are:

People with bipolar disorder also experience depressive episodes.

Can MRI detect depression?

Healthcare professionals do not use MRI scans to diagnose or detect depression.

Researchers often use MRI scans to learn more about depression in scientific studies. However, these scans cannot help doctors diagnose depression.

Can a blood test detect depression?

Doctors do not use blood tests to detect or diagnose depression.

However, research into chemicals in the bloodstream and depression is ongoing.

PDD or chronic depression is a depressive disorder that lasts at least 2 years. People with PDD have ongoing symptoms that are usually milder in severity than MDD. Treatment and management of PDD typically involve a combination of psychotherapy and medications.

A person should speak with a healthcare professional if they are experiencing symptoms of PDD. Healthcare professionals can accurately diagnose mental health conditions and recommend suitable treatments.