Mental disorders are common in the United States and internationally. An estimated 22 percent of Americans ages 18 and older—about 1 in 5 adults—suffer from a diagnosable mental disorder in a given year.(1) When applied to the 1998 U.S. Census residential population estimate, this figure translates to 44.3 million people. (2) In addition, 4 of the 10 leading causes of disability in the U.S. and other developed countries are mental disorders-major depression, bipolar disorder, schizophrenia, and obsessive-compulsive disorder(3). Many people suffer from more than one mental disorder at a given time.
In the U.S., mental disorders are diagnosed based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV).(4)
Depressive disorders encompass major depressive disorder, dysthymic disorder, and bipolar disorder. Bipolar disorder is included because people with this illness have depressive episodes as well as manic episodes.
Approximately 18.8 million American adults, 5 or about 9.5 percent of the U.S. population age 18 and older in a given year, 1 have a depressive disorder. Nearly twice as many women (12.0 percent) as men (6.6 percent) are affected by a depressive disorder each year. These figures translate to 12.4 million women and 6.4 million men in the U.S. (5) Depressive disorders may be appearing earlier in life in people born in recent decades compared to the past.(6) Depressive disorders often co-occur with anxiety disorders and substance abuse.(7)
Major Depressive Disorder
Major depressive disorder is the leading cause of disability in the U.S. and established market economies worldwide. 3 Major depressive disorder affects approximately 9.9 million American adults,5 or about 5.0 percent of the U.S. population age 18 and older in a given year. 1 Nearly twice as many women (6.5 percent) as men (3.3 percent) suffer from major depressive disorder each year. These figures translate to 6.7 million women and 3.2 million men. 5 While major depressive disorder can develop at any age, the average age at onset is the mid-20s. 4
Symptoms of dysthymic disorder (chronic, mild depression) must persist for at least 2 years in adults (1 year in children) to meet criteria for the diagnosis. Dysthymic disorder affects approximately 5.4 percent of the U.S. population age 18 and older during their lifetime. (1) This figure translates to about 10.9 million American adults. 5 About 40 percent of adults with dysthymic disorder also meet criteria for major depressive disorder or bipolar disorder in a given year. 1 Dysthymic disorder often begins in childhood, adolesc.ence, or early adulthood. (4)
Bipolar disorder affects approximately 2.3 million American adults, 5 or about 1.2 percent of the U.S. population age 18 and older in a given year. 1 Men and women are equally likely to develop bipolar disorder5. The average age at onset for a first manic episode is the early 20s.(4)
In 1997, 30,535 people died from suicide in the U.S.8 More than 90 percent of people who kill themselves have a diagnosable mental disorder, commonly a depressive disorder or a substance abuse disorder. 9 The highest suicide rates in the U.S. are found in white men over age 85. 8 The suicide rate in young people increased dramatically over the last few decades. In 1997, suicide was the 3rd leading cause of death among 15 to 24 year olds. (8) Four times as many men than women commit suicide; 8 however, women attempt suicide 2-3 times as often as men. (10)
Approximately 2.2 million American adults, 2 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.(11)
Schizophrenia often first appears earlier in men, usually in their late teens or early 20s, than in women, who are generally affected in their 20s or early 30s.(11)
Anxiety disorders include panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, generalized anxiety disorder, and phobias (social phobia, agoraphobia, and specific phobia).
Approximately 19.1 million American adults ages 18 to 54, or about 13.3 percent of people in this age group in a given year, have an anxiety disorder.(12) Anxiety disorders frequently co-occur with depressive disorders, eating disorders, or substance abuse.(7,13) Many people have more than one anxiety disorder.(11) Women are more likely than men to have an anxiety disorder. Approximately twice as many women as men suffer from panic disorder, post-traumatic stress disorder, generalized anxiety disorder, agoraphobia, and specific phobia, though about equal numbers of women and men have obsessive-compulsive disorder and social phobia.(11,14,15)
Approximately 2.4 million American adults ages 18 to 54, or about 1.7 percent of people in this age group in a given year, have panic disorder. (12) Panic disorder typically develops in late adolescence or early adulthood.(11) About 1 in 3 people with panic disorder develop agoraphobia, a condition in which they become afraid of being in any place or situation where escape might be difficult or help unavailable in the event of a panic attack.(11) Obsessive-Compulsive Disorder (OCD)
Approximately 3.3 million American adults ages 18 to 54, or about 2.3 percent of people in this age group in a given year, have OCD. 12 The first symptoms of OCD often begin during childhood or adolescence. (11)
Post-Traumatic Stress Disorder (PTSD)
Approximately 5.2 million American adults ages 18 to 54, or about 3.6 percent of people in this age group in a given year, have PTSD. (12)
PTSD can develop at any age, including childhood.(16) About 30 percent of Vietnam veterans experienced PTSD at some point after the war.(17) 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 4.0 million American adults ages 18 to 54, or about 2.8 percent of people in this age group in a given year, have GAD.(12)
GAD can begin across the life cycle, though the risk is highest between childhood and middle age.(11)
Approximately 5.3 million American adults ages 18 to 54, or about 3.7 percent of people in this age group in a given year, have social phobia.(12) Social phobia typically begins in childhood or adolescence.(11)
Agoraphobia and Specific Phobia
Agoraphobia involves intense fear and avoidance of any place or situation where escape might be difficult or help unavailable in the event of developing sudden panic-like symptoms. Approximately 3.2 million American adults ages 18 to 54, or about 2.2 percent of people in this age group in a given year, have agoraphobia.(12) Specific phobia involves marked and persistent fear and avoidance of a specific object or situation. Approximately 6.3 million American adults ages 18 to 54, or about 4.4 percent of people in this age group in a given year, have some type of specific phobia.(12)
The 3 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 18 and an estimated 35 percent of those with binge-eating disorder 19 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.(20)
Community surveys have estimated that between 2 percent and 5 percent of Americans experience binge-eating disorder in a 6-month period.(19,21)
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.(22)
Attention Deficit Hyperactivity Disorder (ADHD)
ADHD, one of the most common mental disorders in children and adolescents, affects an estimated 4.1 percent of youths ages 9 to 17 in a 6-month period.(23) About 2-3 times more boys than girls are affected(24). ADHD usually becomes evident in preschool or early elementary years. The disorder frequently persists into adolescence and occasionally into adulthood. (25)
Autism affects an estimated 1 to 2 per 1,000 people. (26) Autism and related disorders (also called autism spectrum disorders or pervasive developmental disorders) develop in childhood and generally are apparent by age 3. (27) Autism is about 4 times more common in boys than girls. Girls with the disorder, however, tend to have more severe symptoms and greater cognitive impairment.(27)
Alzheimer's disease, the most common cause of dementia among people age 65 and older, affects an estimated 4 million Americans. As more and more Americans live longer, the number affected by Alzheimer's disease will continue to grow unless a cure or effective prevention is discovered. The duration of illness, from onset of symptoms to death, averages 8 to 10 years.