Persistent depressive disorder (PDD) and major depressive disorder (MDD) are two forms of depression. Both conditions can affect a person’s daily life.
PDD, formerly called dysthymic disorder, affects 1.5% of adults in the United States. Females are more likely to have PDD than males.
MDD is one of the most common mental health disorders in the U.S., affecting 7.1% of adults in the country. It is also more likely to develop in females than males.
A key difference involves the duration of symptoms. For a doctor to diagnose PDD in an adult, symptoms must have lasted for at least
Below, learn more about the differences between major and persistent depressive disorders. We describe their symptoms, causes, treatment, and more.

PDD and MDD have very similar symptoms. It
MDD symptoms
There are many symptoms of MDD, and not all of them
The
- having a depressed mood that lasts for most of the day
- having less interest or pleasure in most or all activities
- experiencing fatigue
- feeling worthless or guilty
- having difficulty concentrating and making decisions
- unintentionally losing or gaining a significant amount of weight
- having trouble sleeping — insomnia — or sleeping too much
- experiencing a type of restlessness called psychomotor agitation or finding it difficult to think, speak, and do other everyday things, called psychomotor impairment
- having frequent thoughts of death
PDD symptoms
The symptoms of PDD
As with MDD, not every PDD symptom needs to be present at the same time for a person to receive a diagnosis.
PDD symptoms
- feeling depressed or irritable
- having a poor appetite or overeating
- having insomnia or sleeping too much
- experiencing fatigue or low energy
- having low self-esteem
- having trouble concentrating or making decisions
- having feelings of hopelessness
While some causes of MDD and PDD may be similar, there are some crucial differences.
MDD causes
Mood disorders have genetic and external causes. In the case of MDD, scientists
However,
The hippocampus helps with making memories, adapting to stressful situations, and processing emotions. A reduction in the size of this part of the brain can affect its ability to function.
MDD also
The neurotransmitters serotonin, dopamine, and norepinephrine travel through gray matter. When MDD reduces the amount of gray matter, this
Factors that increase the chances of developing MDD
- having had depressive episodes
- experiencing a stressful life event
- having a family history of MDD
- having chronic medical conditions
- having dementia
- having anxiety
- engaging in substance abuse
PDD causes
Research into the causes of PDD is ongoing, but
Other causes of PDD are genetic, environmental, and psychological. Some of these include:
The diagnostic processes for PDD and MDD are similar.
MDD diagnosis
Doctors, including psychiatrists, use the symptoms of MDD to diagnose it.
For a doctor to recognize MDD, a person must have
The symptoms have to adversely affect a person’s social well-being, their job, or other important aspects of their life.
The symptoms that doctors use to diagnose MDD are symptoms of major depressive episodes. For a doctor to recognize the disorder, a person must also have experienced at least two of these episodes separated by at least
PDD diagnosis
Doctors likewise use the symptoms of PDD to diagnose the disorder.
To receive the diagnosis, a person must have
These symptoms need to adversely affect a person’s social well-being, their job, or other important areas of their life.
For a person to receive a diagnosis of PDD, the symptoms cannot have been absent for
Psychiatrists and other doctors use very similar approaches to MDD and PDD treatment.
MDD treatment
There are several treatment options for MDD.
Doctors, including psychiatrists, help determine
For mild MDD, they often recommend psychotherapy and monitoring symptoms. However, a doctor may recommend medication for a person with MDD symptoms of any severity.
Treatments for moderate MDD often include psychotherapy and medication.
Psychotherapy-based treatments
- cognitive behavioral therapy (CBT)
- behavioral activation
- interpersonal psychotherapy
Medications for MDD
- selective serotonin reuptake inhibitors (SSRIs), such as sertraline (Zoloft) and citalopram (Celexa)
- serotonin-norepinephrine reuptake inhibitors (SNRIs), such as venlafaxine (Effexor) and duloxetine (Cymbalta)
- other medications, such as bupropion (Wellbutrin) and mirtazapine (Remeron)
Medication usually starts at a low dosage, to be increased if needed. MDD symptoms could improve in as few as
Using medication and psychotherapy can be
PDD treatment
Treatment for PDD is
- methods of psychotherapy, such as CBT
- medication, including SSRIs or SNRIs
An SSRI is
However, a number of factors go into decisions about medication. Doctors work with people to ensure that the choice and dosage of medication best suits their needs.
PDD and MDD are two forms of depression that have similar symptoms and treatment methods.
The main difference concerns the duration of symptoms. PDD symptoms last for at least 2 years, in adults, while people with MDD experience depressive episodes that are separated by at least 2 months.
Genetic, social, and physical factors cause PDD and MDD. Various parts of the brain play important roles in the development of these disorders.
Treating PDD and MDD may involve methods of psychotherapy, such as CBT, and medications, including SSRIs and SNRIs. These may be especially effective in combination.