At least 21 million Americans experience a major depressive episode. Risk factors include family history, history of trauma, substance use disorders, and other mental health issues.

Sadness, grief, and even passing feelings of hopelessness or despair are part of the human experience. Most people have these feelings from time to time, but they will generally improve within a few days or as the situation changes.

Major depressive disorder (MDD) — also called major depression or clinical depression — involves a low or sad mood that persists for 2 weeks or longer. You might also notice declining energy, loss of appetite, feelings of emptiness, and a loss of interest in the things you used to enjoy.

Untreated depression can affect physical and emotional well-being, as well as your personal life and relationships.

But support from a mental health professional can make a big difference in your symptoms, and you have plenty of options for treatment — including therapy, medication, and complementary treatments.

Depression is common. According to the World Health Organization (WHO), about 280 million people worldwide have depression, including 5% of the world’s adults and 5.7% of adults above age 60.

The National Insitute of Mental Health (NIMH) estimates that 21 million U.S. adults had at least one major depressive episode in 2021. This represents 8.3% of the U.S. adult population.

Still, many people with depression don’t get help for their symptoms, so the actual number of people living with depression may be higher:

  • An estimated 60% of people who have depression don’t seek professional support, in part due to the stigma of depression.
  • The WHO notes that over 75% of people living in low-income or middle-income countries never get treatment for depression due to treatment barriers.

How much have depression rates increased?

According to a 2022 study looking at 2015 through 2020, the rates of depression in the United States increased as follows:


There was no increase in older age groups.

In general, the researchers found that in 2020, having depression for longer than a year occurred in 1 in 10 Americans and almost 1 in 5 adolescents and young adults.

Several types of depression exist. Symptoms may show up in slightly different ways.

Major depressive disorder

When people refer to “depression,” they’re often talking about major or clinical depression.

The NIMH estimates that 21 million adults, or 8.3% of all adults in the United States, had at least one episode of major depression in 2021.

Episodes of major depression were more common among:

  • females (10.3% compared to 6.2% in males)
  • people between the ages of 18 and 25 (18.6%)
  • people who describe themselves as being of two or more races or ethnicities (13.9%)

Persistent depressive disorder

Persistent depressive disorder, or dysthymia, is a type of chronic depression that lasts 2 years or longer. It generally involves milder depression symptoms that are more long lasting.

The mood changes associated with persistent depression may be less severe, but they can still cause plenty of distress.

Estimates suggest that 3% of U.S. people may have this type of depression.

Bipolar disorder

Not everyone who lives with bipolar disorder will experience an episode of depression, but many do.

People with bipolar I disorder have episodes of mania, sometimes followed by episodes of depression. People with bipolar II have alternating episodes of depression and hypomania.

Research from 2018 suggests the lifetime prevalence of people who develop bipolar I is around 1%, though estimates vary.

According to a mix of data from older epidemiological studies, as reported in research from 2018:

  • The lifetime prevalence of bipolar I is around 0.6–1.06%, with additional older data from a 2012–2013 national survey suggesting it could be as high as 2.1% in the United States.
  • The lifetime prevalence of bipolar II is around 1.57%.

Learn more about the types of bipolar disorder.

Seasonal depression

Major depressive disorder with seasonal patterns — sometimes called seasonal affective disorder or seasonal depression — involves changes in mood that happen alongside changes in the seasons.

For many people, this type of depression begins in autumn and lasts through winter, but some experience seasonal depression symptoms in spring and summer.

The American Psychiatric Association notes that around 5% of American adults experience seasonal depression. For these people, symptoms generally linger for around 40% of the year.

Seasonal depression more commonly affects:

  • females
  • young adults
  • people living at higher altitudes

Symptoms of seasonal depression also return each year for almost 70% of people living with the condition.

Postpartum depression

Temporary feelings of sadness and fatigue, along with shifts in mood, are very common after childbirth. These “baby blues” can have a range of causes, including:

  • hormonal changes
  • lack of sleep
  • pressures of caring for a newborn

But if these mood changes intensify or persist for more than a week or two, you could be experiencing major depressive disorder with peripartum onset. This is commonly called postpartum depression.

According to estimates, 6.5–20% of people develop postpartum depression after giving birth. The condition more commonly affects new parents who:

  • are adolescents
  • live in urban areas
  • deliver premature babies

Postpartum depression can lead to social withdrawal, loss of appetite, and unwanted emotions. It can also affect your relationship with your baby.

It’s important to note that this condition doesn’t develop because of anything you did or did not do as a parent.

Learn more about getting support.

Psychotic depression

Major depressive disorder with psychotic features (aka psychotic depression) describes depression that involves psychosis, hallucinations, delusions, or paranoia.

Research on depression with psychotic features remains fairly limited in comparison to research on other types of depression. However, some experts believe this subtype is more common than previously believed.

According to a 2021 research review, depression with psychotic features affects:

  • about 4 in every 1,000 adults
  • between 14 and 30 adults in every 1,000 people over age 60

The same researchers note that symptoms of psychosis develop during an episode of depression for:

  • 10–19% of adults in community samples
  • 25–45% of adults receiving inpatient care
  • 24–53% of older adults receiving inpatient care

The symptoms of depression can range from mild to severe. In the 2019 National Health Interview Survey, adults were asked about their symptoms over the past 2 weeks and found that:

  • 2.8% of adults had severe symptoms
  • 4.2% had moderate symptoms
  • 11.5% had mild symptoms

You may have depression if feelings of sadness or emptiness linger through most of each day for longer than 2 weeks. Other key mental and emotional symptoms include:

  • unusual irritability or difficulty managing anger
  • changes in energy, including restlessness, fatigue, or a sense of being slowed down
  • loss of enjoyment in your usual interests, including hobbies or spending time with friends and loved ones
  • a tendency to ruminate on regrets and fears, mistakes you believe you’ve made, or other dark thoughts
  • brain fog, or difficulty concentrating and making decisions
  • thoughts of death or suicide

Need help now?

Depression can involve deeply distressing thoughts and emotions, including feelings of guilt, worthlessness, and thoughts of suicide.

Living with depression is also known to increase your chances of experiencing suicidal thoughts. In the United States alone, depression leads to about 40,000 deaths by suicide each year.

If you’re feeling overwhelmed by painful and unbearable thoughts, you don’t have to manage them alone. Trained crisis counselors can offer compassionate support by talking through your feelings and exploring options for more support.

Reach out and connect by:

Find more suicide prevention resources here.

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Experts believe depression develops in response to a combination of factors, including brain chemistry, hormones, and genetics. In other words, there’s no single cause of depression.

Some risk factors of depression include:

  • A history of trauma or abuse: A 2021 study in the Netherlands found that among adults with a history of depression or anxiety, at least 48.6% had experienced at least one type of childhood trauma.
  • A history of other mental health conditions: Post-traumatic stress disorder, anxiety disorders, and obsessive-compulsive disorder have all been linked to depression.
  • Chronic conditions: Estimates suggest that 9.3–25% of people living with chronic conditions, such as diabetes or chronic pain, also have depression.
  • Substance use disorders: Anywhere from 12–80% of people with a substance use disorder experience depression at the same time.
  • Family history: People with a family history of depression are at least 3 times as likely to develop depression.

Learn more about potential causes and risk factors for depression.

There are various treatments for depression. According to the American Psychiatric Association, a combination of antidepressants and therapy is, on average, more effective. But both treatments have about the same effectiveness when used alone.

Between 40% and 60% of people taking antidepressants for moderate or severe depression notice improved symptoms after 6–8 weeks. In contrast, between 20% and 40% of people taking a placebo noticed similar improvements.

However, about 23% of people taking antidepressants have a relapse of depression symptoms within a year or two. In contrast, nearly half of those taking placebos have a relapse within the same timeframe.

Evidence-based therapy for depression, such as cognitive behavioral therapy, also led to remission in one-third of subjects, according to a 2021 study.

Online therapy options

Read our review of the best online therapy options to find the right fit for you.

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While you can take steps to lower your risk of developing depression, experts have yet to find a way to prevent it completely. That said, learning to recognize the signs of depression and knowing how to get help when needed can help you address symptoms early before they get worse.

Statistics can absolutely have value, but they may not always seem relevant to your specific circumstances.

Maybe you have no family history of depression, for example, or any other key risk factors. Perhaps you experience symptoms in an uncommon pattern, like depression that worsens in summer.

No matter what symptoms you experience or how they show up, a trained therapist can help you begin to explore possible causes and offer guidance on effective treatments.