You get up every day and go through the motions. Some days are easier than others, but through it all, you have a sense of heaviness in your heart that’s invisible to the world.

“You don’t look depressed!” you hear from those around you, unsure of what this means. How are you supposed to look when you live with depression?

But then, one day, someone describes you as high functioning. What does that mean?

Depression doesn’t look the same from person to person — and your own depression symptoms may change or evolve over time. If you’re still able to go about your day and people can’t tell you’re depressed, you may be considered high functioning.

As far as official diagnostic criteria goes, you won’t find a condition called high-functioning depression. Although it’s been studied and referred to in medical circles, this isn’t a formal diagnosis or type of depression.

That said, you may still identify as having high-functioning depression or currently feel high functioning, and that’s valid.

As far as diagnoses go, your symptoms and experience might be explained by persistent depressive disorder (PDD).

Some people — including medical professionals — sometimes refer to persistent depressive disorder as high-functioning depression. But this term can be misleading.

Persistent depressive disorder is a type of depression that’s defined by a low mood that’s present for at least 2 years in adults or 1 year in children and teens. It’s also been called chronic depression or dysthymia.

An estimated 1.5% of U.S. adults (more than 3 million people) live with PDD. It’s more commonly diagnosed in females than males.

The symptoms of PDD are similar to those seen in major depressive disorder (MDD), although they’re often not as severe or intrusive.

Because of this, you might live with symptoms and still “function” in many aspects of your life. You may not even be able to pinpoint the moment you started having symptoms.

PDD used to be called dysthymic disorder or dysthymia. The name was changed to persistent depressive disorder to emphasize the duration of the symptoms rather than their severity.

This doesn’t mean your symptoms don’t feel severe enough to take away joy from your activities or hope.

In fact, you might be able to do plenty of things, but inside, you have low motivation and constant sadness. While you might still manage to get out of bed every morning, maybe it’s still really hard.

For some people, PDD might feel like living with a chronic low-grade fever. You can get up and go, but it doesn’t mean you’re 100% well.

Some symptoms of high-functioning depression are the same experienced in other types of depression. The main difference is that symptoms must last at least 2 years or longer for someone to be diagnosed with PDD.

The most common symptom of PDD is a constant low mood, or low mood on most days.

Other symptoms include:

  • poor appetite or overeating
  • sleep issues like insomnia or hypersomnia
  • low energy and fatigue
  • poor self-esteem
  • difficulty concentrating
  • trouble making decisions
  • feelings of emptiness, hopelessness, or despair

Two or more of these symptoms must be present for a diagnosis.

Most people with PDD have experienced major depressive disorder (sometimes known as clinical depression) at least once in their lifetime.

According to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), you’ll fit the criteria for a PDD diagnosis if:

  • during the 2-year period of low mood, you’ve never been without symptoms for more than 2 months at a time
  • you’ve never had an episode of mania, a mixed episode, or hypomania, or experienced any symptoms of cyclothymic disorder
  • your symptoms aren’t better explained by other conditions, such as a psychotic disorder
  • your symptoms aren’t the result of substance use or a general medical condition
  • your symptoms cause significant distress or impairment in some areas of your life

They also note that if major depressive disorder has been continuously present for 2 years, you’ll likely receive a dual diagnosis of PDD and MDD. For example, you’ve had symptoms of PDD for several years now and once had a major depressive episode.

When reaching a diagnosis, your doctor will often start by ordering a few lab tests.

These tests can help them rule out conditions that might also explain your low mood, like:

Once these have been checked and cleared, a health professional may talk with you about:

  • your concerns
  • your thoughts about yourself and the world
  • the state of your past and current relationships
  • details of your daily life

They can then use your responses to see what diagnosis might fit your symptoms best.

If they determine you’ve experienced low mood and other symptoms for most days in the past 2 years, they’ll likely diagnose persistent depressive disorder. If you’re diagnosed before age 21, it’s considered early onset, while after is considered late onset.

The causes and contributing factors of PDD vary and may be linked to a combination of environmental and biological factors, along with personality.

Some potential causes and factors may include:

  • family history of depression or other mental health conditions
  • personal or family history of trauma
  • imbalances in your brain chemistry
  • personality traits such as low self-esteem, or avoidant or pessimistic traits
  • environmental factors such as:
    • death of a loved one
    • having a chronic medical illness
    • history of abuse, trauma, or neglect
    • poverty or deprivation
    • living with other mental health conditions such as anxiety
    • going through a difficult divorce or illness in the family
    • chronic social or academic difficulties

Treatment options for PDD are very similar to those for major depressive disorder. Often, a combo of medication and psychotherapy are recommended.

In fact, a combination of these might work better for some people with PDD than either treatment on its own.

Medications

If you’re prescribed medications, it will likely be an antidepressant. Your doctor will probably start you on a class of antidepressant called selective serotonin reuptake inhibitors (SSRIs).

SSRIs work by blocking serotonin — a neurotransmitter that helps regulate mood — from quickly leaving your brain. This creates more serotonin, which may help relieve depression symptoms.

Some common SSRIs include:

Your doctor may also consider prescribing a serotonin-norepinephrine reuptake inhibitor (SNRI).

SNRIs work by affecting both serotonin and norepinephrine in the brain.

Some common SNRIs are:

Psychotherapy

Cognitive behavioral therapy (CBT), psychodynamic therapy, and interpersonal therapy (IPT) are evidence-based psychotherapy approaches for depression.

In CBT, you and your therapist will focus on reframing negative thinking patterns and behaviors that may be contributing to your depression symptoms.

In IPT, you’ll focus on your interpersonal relationships and social skills to reduce stress in your life.

A new therapeutic model called cognitive-behavioral analysis system of psychotherapy (CBASP) has also started showing promise as a treatment for chronic depression. However, it hasn’t become the standard of care.

CBASP may help you develop a sense of personal safety in your relationships, and to work on reversing interpersonal avoidance patterns that might be causing you distress.

PDD and MDD share similar symptoms, such as fatigue, appetite changes, feelings of hopelessness, and poor concentration.

The main difference between the two conditions is the duration of your symptoms.

When you live with PDD, you may experience low mood and depression symptoms most days of your life for at least 2 years.

If you live with MDD, you might experience depressive episodes of 2 weeks or longer, but they’re often separated by at least 2 months or more.

In PDD, chronic symptoms often feel less severe, allowing you to sometimes function well in your work and relationships — thus the reason you might be described as high functioning.

Also, to receive a PDD diagnosis, you must experience at least two depressive symptoms, while an MDD diagnosis requires at least five.

Persistent depressive disorder also tends to begin early — sometimes in childhood, adolescence, or young adulthood.

Symptoms may also develop slowly, making it difficult for you to identify them at first or leading you to believe they’re just part of who you are.

Depressive episodes are a feature in both PDD and bipolar disorder.

However, when you live with bipolar disorder, you may also experience episodes of mania or hypomania, which can last anywhere from several days to a couple of months.

People with PDD experience what’s called unipolar depression, meaning depression only (no “up” periods).

Some people who are diagnosed with personality disorders also experience symptoms of chronic depression.

One study in 2010 on personality disorders explored how they might overlap in your daily life.

Specifically, those who had a personality disorder and received a diagnosis of dysthymic disorder (now PDD) were more likely to experience longer term symptoms of the personality disorder than those who didn’t have PDD.

This was particularly true for cases of borderline personality disorder and avoidant personality disorder.

Compared to those with only one diagnosis, study participants with both conditions also showed:

  • poorer social adjustment
  • lower life satisfaction
  • more challenges in relationships

Persistent depressive disorder is sometimes referred to as high-functioning depression. However, the latter isn’t a formal diagnosis and can be misleading.

PDD involves long lasting symptoms of depression that might make it harder to function in your daily tasks, even if you feel slightly better at times.

While symptoms may not be as severe as other types of depression, they can still cause great distress.

Reaching out for support — from professionals, your family and friends, and your community — can make a difference in managing your symptoms and improving your quality of life.