How Persistent Depressive Disorder Is Diagnosed

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Persistent depressive disorder, formerly known as dysthymia, is a mood disorder with chronic (long-lasting) symptoms that may be less severe than those of major depressive disorder but last longer.

The exact cause of persistent depressive disorder is unknown. However, there are specific criteria that are used by medical professionals to diagnose persistent depressive disorder. You may also be able to conduct a self-screening as an initial step to seeking help and counsel from a professional.

Knowing how persistent depressive disorder is diagnosed can help you better understand what you’re feeling and lead you to treatment options. Learn more about the steps to diagnosis.

woman sitting alone at home

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Professional Screenings

Professional screenings are the most reliable way to determine if your depressive symptoms meet the criteria for persistent depressive disorder. You can go to your primary care provider to get screened, and they may refer you to a mental health specialist from there. There is nothing you need to prepare before getting screened. However, knowing in advance a little bit of what to expect can help ease your mind.

Screening includes:

  • An overview of your mental health symptoms: This will usually involve you talking about your feelings, mood, sleep habits, and behaviors with your healthcare provider and/or a mental health professional they refer you to.
  • Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria: This is a manual for assessment and diagnosis of mental disorders.
  • PHQ-9 (Patient Health Questionnaire-9): This is another screening tool for depression that screens for the severity of depression.

Preparing for Your Screening

It is important to be open and honest during your screening. To help you during the screening, bring a list of:

  • Symptoms
  • Feelings
  • Behaviors

Having your thoughts written down ahead of time can make it easier to talk with your healthcare provider and may help them get a sense of your previous experience with chronic low mood.

Labs and Tests

Some symptoms of depression overlap with those of other health conditions. So your practitioner might also do a physical exam and order blood and/or urine tests to rule out other conditions.

There are a host of tests your healthcare provider might order to check for other health-related reasons that could be contributing to your depressive symptoms. 

The Importance of Ruling Out Other Health Conditions

It's important to uncover any underlying medical issues that might be present when treating depression.

If the test results come back normal, your healthcare provider is likely to be more confident that your depressive symptoms are not due to an underlying health condition.

This type of screening is important for catching health issues you or your practitioner might not have known about before proceeding to the next step of your recovery.

Self/At-Home Testing

There are informal screenings you can do yourself to help you get a sense of whether your moods, behaviors, and other symptoms might be indicative of persistent depressive disorder. Doing so can then help get the ball rolling on seeking help from a professional. 

Key to Diagnosis

Symptoms of persistent depressive disorder must last for at least two years for you to be officially diagnosed.

In addition to a regularly low mood for at least two years, two or more of the following symptoms must also be present almost all of the time:

  • Feelings of hopelessness
  • Too little or too much sleep
  • Low energy or fatigue
  • Low self-esteem
  • Poor appetite or overeating
  • Poor concentration

Self-Screening Is Not a Replacement for an Expert Evaluation

As straightforward as it might seem to test yourself for depression based on these criteria, remember that self-screening is only part of the process. Getting screened by your healthcare provider or a mental health professional must be done in order for appropriate treatment to commence.

Differential Diagnosis

In addition to ruling out health conditions that might be the cause of depressive symptoms, medical and mental health professionals may conduct a differential diagnosis in which they consider your symptoms in relation to other mental health conditions. In other words, they will use the screening to help differentiate between other mental health conditions that may be behind the presenting symptoms.

Differential diagnoses for persistent depressive disorder include screening for other conditions mentioned in the DSM-5, such as:

  • Major depressive disorder
  • Bipolar disorder
  • Substance/medication-induced depressive disorder
  • Personality disorders


The symptoms of persistent depressive disorder may be less severe than those of major depressive disorder but tend to last longer. To receive a diagnosis, you must see a healthcare professional.

A Word From Verywell

Potentially being diagnosed with persistent depressive disorder can make you feel vulnerable and unsure of what to expect. It is OK to ask for help.

Putting a name to your experience does not define you. Our intent with this article is to give you some starting points for seeking professional help so that you can start on the path to recovery. Getting better and feeling more like yourself is possible, and confronting your experience with the guidance of your healthcare provider or mental health professional gets you one step closer.

You are not alone, and you can and will feel better.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Harvard Health Publishing. Persistent depressive disorder.

  2. MedlinePlus. Depression screening.

By Emily Brown, MPH
Emily is a health communication consultant, writer, and editor at EVR Creative, specializing in public health research and health promotion. With a scientific background and a passion for creative writing, her work illustrates the value of evidence-based information and creativity in advancing public health.