Depression Statistics and Resources: Context and Implications of the Disorder

Depression Facts – Overview

Beginning from a national perspective, Stanford Medicine estimates that at least 10% of Americans will experience major depression in their lifetime.¹ In 2021, an estimated 21.0 million adults in the US had at least one major depressive episode (8.3% of all US adults).² These numbers reflect a sobering truth about depression in the US — it is relevant and relatively common, only increasing in the past years.

This is defined here as a period of at least two weeks when an individual might exhibit the following:²

• Depressed mood
• Loss of interest in normal activities
• Majority of specified symptoms such as problem with energy, concentration, and self-worth

The Most Common Types of Depression

A common misconception about depression is that it can be cleanly divided into two categories — requires treatment and does not require treatment. However, depression exists on a spectrum, encompassing many forms, and the experience of one individual does not always mirror that of another. Each type of depression has distinct symptoms, mechanisms, and impacts, making diagnosis and treatment a highly individualized process.

The following list describes five common forms of depression:

• Major depressive disorder (MDD): In 2021, an estimated 21.0 million adults in the US had at least one major depressive episode (8.3% of all US adults).²
• Persistent depressive disorder (PDD): Between 2001-2003, about 1.5% of US adults experienced persistent depressive disorder annually.³
• Bipolar disorder: Between 2001-2003, bipolar disorder affected about 2.8% of the US population age 18 and older.⁴
• Seasonal affective disorder (SAD): In a given year, about 5% of the US population experiences seasonal depression.⁵
• Substance/medication-induced depressive disorder: About 20% of Americans with a mood disorder like depression also have an alcohol or substance use disorder.⁶

Risk Factors for Depression

There are certain risk factors that can make individuals more vulnerable to depression in its various forms and types. Some people believe that the presentation of the disorder is exclusively linked to trauma, situational stimuli, and external events, but the truth is more nuanced.

• 40% of people with depression can trace it to a genetic link.⁷
• People with parents or siblings with depression are almost five times as likely to develop it compared to someone who doesn’t have a relative with depression.⁷
• 60% of people with depression can trace it to environmental factors including:⁸
  • major life changes (good or bad)
  • trauma/stress
  • other illnesses/medication
  • substance abuse

The above-mentioned risk factors — genetic or environmental — are comparable based on the number of incidences. It’s worth noting, however, that many people with depression can trace it back to some combination of the both. In other words, the risk factors that lead to someone’s depression may be both hereditary and situational.

Global Depression Statistics

Switching to a global lens, depression statistics show that it’s a leading cause of disability in the world, and those numbers, which correspond with population growth, are only increasing.⁹

• Approximately 280 million in the world suffer from depression worldwide.⁹
• Between 2005-2015, the global estimate of people living with depression increased by 18.4%.¹⁰
• Almost half of people with depression live in highly-populated global areas.¹⁰
• There’s been a proportionate increase in entire age groups that experience depression more prevalently.¹⁰

Depression Rates by Age

A major depressive disorder can develop at any age; however, the median onset age is 32.5.¹¹ Also, just as depression is a leading cause of disability worldwide, it is the leading cause of disability for ages between 15-44 in the United States.¹² In general, rates of prevalence vary by age, but tend to peak in adulthood.¹⁰

As recently as 2021, researchers uncovered the following information about depression based on age:²

• Prevalence of adults with a major depressive episode was highest among ages 18-25 (18.6%)
• An estimated 5.0 million adolescents (aged 12-17) in the US had at least one major depressive episode.

Depression Rates by Income Level

Many studies also link depression to socioeconomic status, poverty, and income levels. Poverty’s impact on mental health is well documented and countries that have experienced increased poverty levels and an influx of income inequality in recent years may also experience rising rates of depression.

• In two age groups—18-39 and 40-59—people with income below the federal poverty level had higher rates of depression than those with higher income.¹³
• 8.7% of adults with income below federal poverty levels experienced serious psychological stress.¹³
• Between 76-85% of people in low- and mid-income countries receive no treatment for their depression.¹⁴

Depression Rates Within Minority Groups

Major depression statistics and factors associated with depression have also been found more frequently among members of minority groups, namely Hispanic and Black communities.¹⁵ Since the Great Recession, significantly and in relation to the aforementioned data on depression rates and income level, research has shown a considerable economic divide in the US with minority groups falling behind.

• In 2003, major depression was found most prevalent among:¹⁵
  • Hispanics (10.8%)
  • African Americans (8.9%)
  • Caucasians (7.8%).
• The odds of depressive disorders among older Hispanics were 44% greater than among white people.

Depression Rates by Sexual Orientation & Gender Identity

Sexual and gender minority individuals also experience identity-based stressors that contribute to development of depression.¹⁶ While there is still limited research on the topic, existing studies show that there are elevated rates of depression, as well as suicide, social anxiety, generalized anxiety, and exposure to trauma in sexual and gender minority individuals.¹⁶ Not only that, but rates of anxiety and depression in sexual minority individuals are roughly double those of heterosexuals.¹⁶

Depression Rates by Gender

Research shows that depression in women (6.0%) is more common than depression in men (4.0%).¹⁷
Additional depression statistics surrounding gender include:

• Prevalence varies by region, ranging from 2.6% among males in the Western Pacific Region to 5.9% among females in the African Region.¹⁸
• In 2021, prevalence of a major depressive episode was higher in adult females (10.3%) compared to males (6.2%).²
• In 2021, prevalence of a major depressive episode was higher among adolescent females (29.2%) compared to males (11.5%).²
• One study showed that women had a 42% chance of hereditary depression, while men only had a 29% chance.⁸

Depression Rates of People With Co-Occurring Diagnoses

The risk of depression is generally higher among individuals with co-occurring medical diagnoses such as heart disease, stroke, cancer, and diabetes.¹⁹ Unfortunately, warning signs are often discounted or masked by the illness, which results in the treatment of symptoms, but not the treatment of the underlying diagnosis.

• Depression occurs in 40-65% of patients who have experienced a heart attack, and in 18-20% of people with coronary heart disease.¹⁹
• Depression occurs in 10-27% of stroke survivors and typically lasts one year.¹⁹
• One in four people with cancer also suffer from clinical depression.¹⁹
• People with onset diabetes have a 25% chance of having depression.¹⁹

If someone with a co-occurring disease is struggling with depression, both the disease and the disorder need to be treated.

Depression and Suicide

Suicide is one of the leading causes of death in the US, making it a serious health concern. Statistics illustrate how individuals belonging to minority groups, including racial minorities and LGBTQ+ are generally at a higher risk. On a global scale, 703,000 people die by suicide every year.²⁰

• Suicide is the 11th leading cause of death in the US.²¹
• In 2021:²¹
  • 48,183 Americans died by suicide.
  • there were roughly 1.70 million suicide attempts.
  • men died by suicide 3.90 times more often than women.
• The rate of suicide is highest in middle-aged white men.

Treatment for Depression

There are several methods and modalities of treatment for depression. The most common treatment for depression is therapy and antidepressant medications, mainly selective serotonin reuptake inhibitors (SSRIs). The general level of effectiveness in psychotherapy across age groups was medium to high, with lowest effect in children and adolescents.²² In one study with and without antidepressants, about 20-40 out of 100 people who took a placebo noticed an improvement within six to eight weeks, while about 40-60 out of 100 people who took an antidepressant noticed an improvement within six to eight weeks.²³

Additional methods of treatment for depression include:

• Brain stimulation therapies, like transcranial magnetic stimulation (TMS)
• Hypnotherapy
• Group therapy
• Alternative methods like acupuncture and nutrition-related treatment