Mental disorders are common in the United States and internationally. An estimated 26.2 percent of Americans ages 18 and older - about one in four adults - suffer from a diagnosable mental disorder in a given year. When applied to the 2004 U.S. Census residential population estimate for ages 18 and older, this figure translates to 57.7 million people. Even though mental disorders are widespread in the population, the main burden of illness is concentrated in a much smaller proportion - about 6 percent, or 1 in 17 - who suffer from a serious mental illness. In addition, mental disorders are the leading cause of disability in the U.S. and Canada for ages 15-44. Many people suffer from more than one mental disorder at a given time. Nearly half (45 percent) of those with any mental disorder meet criteria for 2 or more disorders, with severity strongly related to comorbidity.

The Numbers Count: Mental Disorders in America

Mood Disorders 

• Major Depressive Disorder 
• Dysthymic Disorder 
• Bipolar Disorder 
• Suicide

Schizophrenia

Anxiety Disorders   

• Panic Disorder  
• Obsessive-Compulsive Disorder (OCD)  
• Post-Traumatic Stress Disorder (PTSD)  
• Generalized Anxiety Disorder (GAD)  
• Social Phobia  
• Agoraphobia  
• Specific Phobia

Eating Disorders

The burden of mental illness on health and productivity in the United States and throughout the world has long been underestimated. Data developed by the massive Global Burden of Disease study conducted by the World Health Organization, the World Bank, and Harvard University, reveal that mental illness, including suicide, accounts for over 15 percent of the burden of disease in established market economies, such as the United States. This is more than the disease burden caused by all cancers.

Mood Disorders
Mood disorders include major depressive disorder, dysthymic disorder, and bipolar disorder.

• Approximately 20.9 million American adults, or about 9.5 percent of the U.S. population age 18 and older in a given year, have a mood disorder.  
• The median age of onset for mood disorders is 30 years.  
• Depressive disorders often co-occur with anxiety disorders and substance abuse.

Major Depressive Disorder  

• Major Depressive Disorder is the leading cause of disability in the U.S. for ages 15-44. 
• Major depressive disorder affects approximately 14.8 million American adults, or about 6.7 percent of the U.S. population age 18 and older in a given year. 
• While major depressive disorder can develop at any age, the median age at onset is 32. 
• Major depressive disorder is more prevalent in women than in men.

Dysthymic Disorder  

• Symptoms of dysthymic disorder (chronic, mild depression) must persist for at least two years in adults (one year in children) to meet criteria for the diagnosis. Dysthymic disorder affects approximately 1.5 percent of the U.S. population age 18 and older in a given year. This figure translates to about 3.3 million American adults.
• The median age of onset of dysthymic disorder is 31.

Bipolar Disorder

• Bipolar disorder affects approximately 5.7 million American adults, or about 2.6 percent of the U.S. population age 18 and older in a given year. 
• The median age of onset for bipolar disorders is 25 years.

Schizophrenia 

• Approximately 2.4 million American adults, or about 1.1 percent of the population age 18 and older in a given year, have schizophrenia.  
• Schizophrenia affects men and women with equal frequency.  
• Schizophrenia often first appears in men in their late teens or early twenties. In contrast, women are generally affected in their twenties or early thirties.

Anxiety Disorders
Anxiety disorders include panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, generalized anxiety disorder, and phobias (social phobia, agoraphobia, and specific phobia).

• Approximately 40 million American adults ages 18 and older, or about 18.1 percent of people in this age group in a given year, have an anxiety disorder. 
• Anxiety disorders frequently co-occur with depressive disorders or substance abuse. 
• Most people with one anxiety disorder also have another anxiety disorder. Nearly three-quarters of those with an anxiety disorder will have their first episode by age 21.5

Panic Disorder  

• Approximately 6 million American adults ages 18 and older, or about 2.7 percent of people in this age group in a given year, have panic disorder.  
• Panic disorder typically develops in early adulthood (median age of onset is 24), but the age of onset extends throughout adulthood.  
• About one in three people with panic disorder develops agoraphobia, a condition in which the individual becomes afraid of being in any place or situation where escape might be difficult or help unavailable in the event of a panic attack.

Obsessive-Compulsive Disorder (OCD) 

• Approximately 2.2 million American adults age 18 and older, or about 1.0 percent of people in this age group in a given year, have OCD.
• The first symptoms of OCD often begin during childhood or adolescence, however, the median age of onset is 19. .

Post-Traumatic Stress Disorder (PTSD)  

• Approximately 7.7 million American adults age 18 and older, or about 3.5 percent of people in this age group in a given year, have PTSD. 
• PTSD can develop at any age, including childhood, but research shows that the median age of onset is 23 years.
• About 19 percent of Vietnam veterans experienced PTSD at some point after the war. The disorder also frequently occurs after violent personal assaults such as rape, mugging, or domestic violence; terrorism; natural or human-caused disasters; and accidents.

Generalized Anxiety Disorder (GAD)

• Approximately 6.8 million American adults or about 3.1 percent of people age 18 and over, have GAD in a given year.
• GAD can begin across the life cycle, though the median age of onset is 31 years old. 

Social Phobia  

• Approximately 15 million American adults age 18 and over, or about 6.8 percent of people in this age group in a given year, have social phobia. 
• Social phobia begins in childhood or adolescence, typically around 13 years of age.

Agoraphobia
Agoraphobia involves intense fear and anxiety of any place or situation where escape might be difficult, leading to avoidance of situations such as being alone outside of the home; traveling in a car, bus, or airplane; or being in a crowded area. 

• Approximately 1.8 million American adults age 18 and over, or about 0.8 percent of people in this age group in a given year, have agoraphobia without a history of panic disorder. 
• The median age of onset of agoraphobia is 20 years of age.

Specific Phobia
Specific phobia involves marked and persistent fear and avoidance of a specific object or situation.

• Approximately 19.2 million American adults age 18 and over, or about 8.7 percent of people in this age group in a given year, have some type of specific phobia.  
• Specific phobia typically begins in childhood; the median age of onset is seven years.

Eating Disorders
The three main types of eating disorders are anorexia nervosa, bulimia nervosa, and binge-eating disorder.

• Females are much more likely than males to develop an eating disorder.
• Only an estimated 5 to 15 percent of people with anorexia or bulimia and an estimated 35 percent of those with binge-eating disorder are male.  
  In their lifetime, an estimated 0.5 percent to 3.7 percent of females suffer from anorexia, and an estimated 1.1 percent to 4.2 percent suffer from bulimia.  
• Community surveys have estimated that between 2 percent and 5 percent of Americans experience binge-eating disorder in a 6-month period.  
• The mortality rate among people with anorexia has been estimated at 0.56 percent per year, or approximately 5.6 percent per decade, which is about 12 times higher than the annual death rate due to all causes of death among females ages 15-24 in the general population.